ASU REVIEW Andrew Taylor,*a Simon Branch,b David Halls,c Marina Patriarcad and Mark Whitee www.rsc.org/jaas Atomic spectrometry update. Clinical and biological materials, foods and beverages a Supra-regional Assay Service, Trace Element Laboratory, Centre for Clinical Science and Measurement, School of Biomedical and Life Sciences, University of Surrey, Guildford, Surrey, UK GU2 7XH. E-mail: [email protected] b The Lord Rank Centre, R. H. M. Technology, Lincoln Road, High Wycombe, Buckinghamshire, UK HP12 3QR c 1A Bloomfield Road, Lesmahagow, Lanark, UK M11 0DF d Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy e Health and Safety Laboratory, Health and Safety Executive, Broad Lane, Sheffield UK S3 7HQ Received 10th February 2005 First published as an Advance Article on the web 3rd March 2005 1 1.1 1.2 1.2.1 1.2.2 1.2.3 1.3 1.3.1 1.3.2 1.3.2.1 1.3.2.2 1.3.2.3 1.3.2.4 1.3.2.5 1.3.3 1.3.3.1 1.3.3.2 1.3.3.3 1.3.3.4 1.3.3.5 1.3.4 DOI: 10.1039/b501936b 1.4 1.5 1.6 1.7 1.7.1 1.7.2 1.7.3 1.7.4 1.7.5 1.7.6 1.7.7 1.7.8 1.7.9 1.7.10 1.7.11 1.7.12 1.7.13 1.7.14 Analysis of clinical and biological materials General reviews and articles Sampling and sample preparation Sample digestion Solid sampling Sample preconcentration Developments in and applications of multi-element techniques Atomic emission spectrometry with the inductively coupled plasma or microwave induced plasma Inductively coupled plasma mass spectrometry and other mass spectrometric techniques Reviews Multielement determination by ICP-MS Laser ablation ICP-MS Secondary ion mass spectrometry Accelerator mass spectrometry X-ray fluorescence spectrometry Reviews Elemental mapping Developments in in vivo XRF determination Determination of elements in tissues by XRF Determination of elements in body fluids by XRF Simultaneous multielement atomic absorption spectrometry Multielement studies using atomic absorption spectrometry Developments in single element techniques Hair and nail analysis Progress for individual elements Aluminium Arsenic Bismuth Boron Cadmium Calcium Chromium Cobalt Copper Gadolinium Gold Iron Lead Lithium 1.7.15 1.7.16 1.7.17 1.7.18 1.7.19 1.7.20 1.7.21 1.7.22 1.7.23 1.7.24 1.7.25 1.7.26 1.7.27 2 3 3.1 3.1.1 3.1.2 3.1.3 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.8.1 3.8.2 3.8.3 3.8.4 3.8.5 3.9 3.9.1 3.9.2 3.9.3 3.9.4 3.9.5 3.9.6 3.9.7 Magnesium Manganese Mercury Molybdenum Nickel Phosphorus Platinum and noble metals Selenium Silver Strontium Titanium Uranides and actinides Zinc Analysis of drugs and pharmaceuticals, traditional medicines and supplements Analysis of foods and beverages Sampling and sample preparation Extraction Digestion Preconcentration Speciation Applications using hydride generation Applications using flame atomic absorption spectrometry Applications using electrothermal atomic absorption spectrometry Applications using inductively coupled plasma-mass spectrometry Applications using other analytical techniques Progress for individual elements Arsenic Lead Mercury Selenium Other elements Single and multi-element analysis of foods and beverages Dietary intake studies Human milk and infant foods Milk and dairy products Wheat, flour and rice Vegetables, nuts and fruits Fish and seafood Drinking waters and non-alcoholic beverages This journal is & The Royal Society of Chemistry 2005 J. Anal. At. Spectrom., 2005, 20, 323–369 323 3.9.8 3.9.9 3.10 3.11 3.12 4 5 Alcoholic beverages Other foods Reference materials and collaborative trials Packaging and cooking Authentication of foods: provenance and origins Conclusions References This annual review covers the literature on the analysis of clinical and biological materials, foods and beverages using atomic spectrometric techniques published in the year up to the end of October 2004. Tables 1 and 2 summarise the details of these publications. Our previous Update1 covered the preceding year up to October 2003. This year, it is evident we are moving into a new phase with many more papers appearing that used dynamic reaction cells or octopole cells with quadrupole ICPmass spectrometers to reduce isobaric interferences, which are so prevalent in biological applications. Innovation and development were also noted with a ‘beam injection’ system for FAAS and the extension of in vivo XRF determination to Ag and As. Speciation of As and Se remains topical and the increased complexity of the situation is now evident with additional species found, many of which still have to be identified. More than 30 years after the appearance of Itai-Itai disease, a consequence of Cd contamination of rice in Japan, it is evident that despite successful remediation work concentrations of Cd in rice are still greater than elsewhere in Asia. This, together with the continuing concern over As in drinking water in Bangladesh, illustrates the importance of vigilance in preventing such tragedies in the future. Abnormally high As concentrations found in fossil skeletons of dinosaur species have led to the suggestion that As toxicity could have contributed to the extinction of dinosaurs in the Chinese Province of Sichuan. Finally, it is appropriate to acknowledge that this is the last Update for which David Halls will be writing. It is not possible to do justice to all that he has contributed. David has written for every one of the Clinical and Biological Materials, Foods and Beverages ASUs since they were established in 1986 and was the Topic Group Coordinator for several years. His contributions are always carefully crafted and, with his long practical experience within the clinical environment, his insight and observations are given with common sense and often with considerable humour too. 1 Analysis of clinical and biological materials 1.1 General reviews and articles In a review entitled Biological fluids as a source of information on the exposure of man to environmental chemical agents, Polkowska et al.2 argued that because the concentrations in biological fluids are low and the matrix complex, direct determination is not possible and some sample pretreatment is necessary. They reviewed techniques for analyte isolation, enrichment and determination for a range of organic and inorganic pollutants and their metabolites. 1.2 Sampling and sample preparation 1.2.1 Sample digestion. A novel total combustion technique was developed by Flores et al.3 Samples of biological material were wrapped in paper and placed on a quartz holder in a quartz vessel used in a commercial microwave oven. Ammonium nitrate was added to the paper and the vessel pressurised to 15 bar with O2. Application of microwave radiation for 20 s ignited the paper with rapid combustion. Residual C was 1.3%, but when an additional reflux step with HNO3 was included, it fell to o0.4%. Results for Cd and Cu in CRMs determined by ETAAS were within 96–105% of certified values. 324 J. Anal. At. Spectrom., 2005, 20, 323–369 Trevizan et al.4 used acid vapour attack to partially digest bovine liver in a modified microwave digestion system. Three sample cups of 4 ml volume were supported in the glass reaction vessel of the microwave oven. Samples of 50–90 mg mass were weighed into the cups and a mixture of NaClO and H2O2 was added. The cups were subjected to attack from the vapour of HNO3–H2SO4 at 120 1C for 15–25 min. The recoveries of Al, Ca, Cu, Fe, Mg, Mn and Zn were evaluated after determination by ICP–AES. Most elements showed quantitative recovery after 25 min heating of a 50 mg sample. For difficult to extract elements, such as Al and Fe, recovery improved when the sample particle size was smaller than 44 mm. 1.2.2 Solid sampling. As part of a study on the determination of Pd by solid sampling ETAAS, Resano et al.5 investigated the determination of Pd in the antihypertensive drug, enalapril maleate. Low levels of Pd remain from the catalyst used in synthesis. Drying and pyrolysis at 1200 1C of 7–10 mg samples repeated five times allowed a total mass of 35–40 mg to be introduced onto the platform. Direct calibration by aqueous solutions was possible and this allowed determination down to an LOD of 0.4 ng g1. The concentration found was 1.9 ng g1 and the method was thus suitable for monitoring concentrations which were expected to be below the legal limit of 20 mg g1. The novel direct flame solid-sampling technique developed by Flores et al. has been applied to the determination of Cu in medicinal plants.6 In this technique, the sample, ground to a particle size of less than 80 mm, is introduced as a dry aerosol into a T-tube below the optical path in an air–C2H2 flame. The aerosol passes through a slit in the tube into the optical path, giving a transient signal which is integrated for 2 s. An LOD for Cu of 0.8 ng was found which corresponded to 1.2 mg g1 if a sample mass of 1 mg was used. 1.2.3 Sample preconcentration. Solid-phase extraction has been explored to obtain greater sensitivity in FAAS. Ganjali et al.7 used octadecyl-bonded silica disks modified with a Schiff base (bis-2-thiophenalpropandiamine) to separate Cd, Cu and Pb from environmental and biological samples. The metal ions were subsequently stripped with acid. The LODs achieved were 0.01, 0.02 and 0.25 mg l1 for Cd, Cu and Pb, respectively. Shamsipur et al.8 modified the octadecyl-bonded silica disks with 1-hydroxy-2-(prop-20 -enyl)-4-(prop-20 -enyloxy)-9,10-anthraquinone to selectively separate Cu from the matrix to obtain enrichment factors of 400 or greater. The LOD achieved was 0.1 mg l1. The success of the method was demonstrated by the determination of Cu in Bovine Liver SRM, tea leaves and a synthetic sea-water sample. Cobalt and Ni were preconcentrated 200-fold by Gopikrishna et al.9 on solid benzophenone as ethyl xanthate complexes at pH 8–10. The solid benzophenone together with metal complexes was subsequently dissolved in DMF for determination by FAAS. The method was applied to the determination of Co and Ni in human hair samples, with trueness demonstrated by analysing the CRMs, NIES Human Hair No. 5 and IAEA Reference Hair HH1. Cloud point formation with mixed micelles was developed by Nascentes and Arruda10 for the preconcentration of Co. The element was complexed with pyridylazo compounds in a mixed surfactant medium of Triton X-100 and SDS. Phase separation was induced by addition of either HCl or NaCl. Cobalt in the surfactant-rich phase was then determined by FAAS. Under optimised conditions, LODs of 1.1 and 1.6 mg l1 were obtained with the use of HCl and NaCl, respectively. Results obtained in the determination of Co in pharmaceutical compounds compared well with those obtained by ETAAS. Further applications of online preconcentration in ETAAS have appeared. Sung and Huang11 combined a laboratory- made FI system with a multielement ETA-AA spectrometer to enable the simultaneous determination of Bi, Cd and Pb in urine. These elements were retained on a microcolumn of Muromac A–1 resin positioned on the autosampler arm and then eluted with 50 ml of 20% v/v HNO3 directly into the graphite furnace. Calibration standards in 0.2% v/v HNO3 went through the same procedure. With a 213 ml sample loop, 10 samples h1 could be analysed and the LODs were 13, 2 and 4.5 ng l1 for Bi, Cd and Pb, respectively. Trueness was demonstrated by analysis of the RMs, Seronorm Trace Elements Urine Level 1 and Level 2. Speciation of Cr in urine was possible in a system developed by Siles Cordero et al.12 With a microcolumn containing Amberlite IRA–910, CrVI was determined and, by replacing with a microcolumn containing silica gel functionalised with 1-(di-2-pyridyl)methylenethiocarbonohydrazide, total Cr could be measured. The concentration of CrIII was obtained by difference. The equipment used is ingeneous as it uses many of the existing facilities on the autosampler. The modified microcolumn replaced the autosampler tip and elution was carried out by sampling eluant (40 ml of 2 M HNO3) and dispensing it into the graphite tube. An external peristaltic pump and rotary valve, used for sampling, were controlled by an electronic control circuit which was initiated by microswitches that were operated when the sampler arm returned to its standby position. The sampling process occurred while the furnace programme was running with the previous sample. No CrVI was found in any of the urine samples examined, although it was satisfactorily recovered from spiked urine samples. Anthemidis et al.13 endeavoured to obtain higher enrichment factors than are normally possible with these on-line systems in ETAAS. They designed a gravitational separator which allowed an organic extract to be effectively separated from a large volume of aqueous phase. In the determination of Cd in natural waters and urine samples by ETAAS after extraction of the complex with ammonium diethyldithiophosphate into IBMK, they obtained an enrichment factor of 24.6, giving an LOD of 2.8 ng l1. and spinal nerves,17 it was found that accumulation of Ca and P was only marked in the trigeminal nerve, with a significant inverse correlation between the S concentration and the concentrations of the major elements, Ca, Mg and P. In human tendons and ligaments,18 again only in one type, the posterior longitudinal ligaments, an increase with ageing was found, this time for Ca and Mg. Iron concentrations decreased significantly with ageing. In an attempt to see whether age-related changes differed between races, these Japanese workers,19studied the accumulation of elements in the arteries and cardiac valves of Thai subjects. They found that accumulation of Ca was generally similar to that found in the Japanese, but was higher in the coronary artery and lower in the thoracic aorta. On-line preconcentration is often used to improve sensitivity to allow other elements to be determined by ICP-AES. Yang et al.20 used a microcolumn in an FI system to preconcentrate and simultaneously determine Bi, Co, Cr, Cu, Y and Yb in biological CRMs with good accuracy. The microcolumn contained nanometer-sized TiO2 loaded with 1-(2-pyridylazo)-2naphthol (PAN). To determine Hg in digested urine, hair and blood samples, Anthemidis et al.21 complexed the Hg on-line with APDC, retained this on PTFE turnings in a column of a combined preconcentration–gas liquid separator module, released the Hg by reduction with SnCl2 and purged the Hg vapor with Ar gas into the ICP. With a 60 s preconcentration time, the LOD was 0.01 mg l1 and 30 samples h1 could be analysed. At a concentration of 1.0 mg l1, the precision was 3.1%. 1.3 Developments in and applications of multi-element techniques 1.3.2 Inductively coupled plasma mass spectrometry and other mass spectrometric techniques 1.3.2.1 Reviews. Traditionally, TIMS has been used for stable isotope studies in humans but, in a review, Sturup22 showed how advances in ICP-MS have led to a broader use of this technique in nutritional research. Developments such as single- and multi-detector ICP-MS and collision and reaction cells have enabled isotope ratios to be measured more precisely and interferences to be removed. The current and future use of ICP-MS in this field was discussed. 1.3.1 Atomic emission spectrometry with the inductively coupled plasma or microwave induced plasma. Matusiewicz and Golik have demonstrated two alternatives to acid digestion in the determination of major and trace elements in solid biological materials by MIP-AES. In the first,14 CRMs were solubilised by TMAH with ultrasonic agitation. After dilution, the suspensions were pumped to a V-groove Babington nebuliser feeding an Ar plasma. Concentrations of major (Ca, K, Mg, Na) and trace (Cu, Fe, Sr, Zn) elements measured in TORT–1 Lobster Hepatopancreas, IAEA–153 Milk Powder and NIST 1577 Bovine Liver agreed satisfactorily with certified values. In the second,15 samples were slurried in 10% v/v HNO3 containing 0.01% v/v Triton X-100 and sprayed with the V-groove nebuliser directly into the microwave cavity torch assembly without desolvation. Calibration was by standard additions. The precision ranged from 7% to 11% and accuracy was demonstrated by the determination of Ca, Cd, Cu, K, Mg, Mn, Na, P, Sr and Zn in three CRMs with satisfactory agreement with certified values. In a further study, Matusiewicz and Kopras16 showed that the hydride-forming elements, As, Bi, Ge, Sb and Se, together with Hg could be determined simultaneously with good sensitivity by trapping the hydrides and Hg vapour at 300 1C on a graphite tube pre-treated with Pd and Au for electrothermal vaporisation at 2100 1C into the MIP. However, the precision and accuracy of the results reported on a range of CRMs leave something to be desired and would suggest that further improvement is necessary. Age-related changes of major elements in parts of the human body were studied using ICP-AES for determination. In cranial 1.3.2.2 Multielement determination by ICP-MS. Sector field ICP mass spectrometers and quadrupole ICP mass spectrometers with collision or reaction cells have become more common and are no longer a research curiosity. These instruments are now occasionally being described in applications because that is what the laboratory has, rather than to solve a problem that older ICP mass spectrometers could not solve. Thus, this review no longer covers applications with these techniques separately. Single element applications of ICP-MS still predominate and these are covered in section 1.7. This section deals with multielement applications. If ICP-MS has a future in the multielement determination of trace elements in serum and urine for a routine laboratory, the method has to be simple. Nakagawa et al.23 examined the determination of As, Cd, Cu, Fe, Pb, Se and Zn in urine after simple dilution 10-fold with 1% v/v HNO3. Matrix interference by NaCl was corrected by the use of added internal standards In, Rh, Tl and Y. Because of isobaric interferences, Fe and Se were measured in collision cell mode with H2–He as the cell gas. A comparison was made with results obtained after microwave digestion of the samples with generally good agreement; however, the acid decomposition introduced more matrix interference from the acid. Results on two urine CRMs showed satisfactory agreement for As, Cu and Pb but results for Cd and Se were higher than the certified or expected values; there were no certified or recommended values for Fe in these CRMs. Simple dilution was also used by de Boer et al.24 in screening for 56 elements in blood and urine samples of a population possibly affected by a firework explosion. Analysis of CRMs and comparison of results with literature values J. Anal. At. Spectrom., 2005, 20, 323–369 325 indicated that results were reasonable for Ba, Cd, Co, Cu, Ni, Sb, Sr, Sn, Tl, Pb and Zn in urine and the same elements in blood except for Ba, Ni, Sb and Sr. Giné et al.25 used on-line dialysis and ID in their method for the determination of Cu, Se, Pb and Zn in serum. The on-line dialysis removed 70% of the Cl, K and Na, thus improving the accuracy by ensuring freedom from matrix effects from the alkaline earths and freedom from isobaric interferences in the determination of 63 Cu, 77Se and 66Zn. Since the recirculation of the sample through the dialysis system took 10 min, one wonders how this method, with its added complexity of ID, could possibly be considered for routine analysis. Forte et al.26 measured Al, Ca, Cu, Fe, Mg, Mn, Si and Zn in urine, serum, blood and cerebrospinal fluid (CSF) of 26 patients with Parkinson’s disease and 13 age-matched controls using ICP-MS and ICPAES. Calcium concentrations in blood, serum and urine and Si in the urine were significantly elevated in the patients. This might have been the result of adjuvants in pharmaceuticals that they were taking. Iron concentrations were elevated in blood and urine while serum Cu and Mg were significantly lower than controls. The authors suggested that Cu and Fe were involved in the pathogenesis of Parkinson’s disease. Interferences in the determination of essential and toxic elements in premature human milk were reduced by the use of H2 in an octopole reaction cell in quadrupole ICP-MS. St. Remy et al.27 demonstrated the reduction of isobaric interference for 52Cr, 54,55,56Fe and 77,78Se. Some interferences were introduced by the cell, e.g., HBr1 affecting 80,82Se. Milk samples were digested with HNO3–H2O2 in a microwave system. Analysis of BCR skimmed milk powder CRM gave results in agreement within the range for those elements (Ca, Cu, Fe, Mg, Na, Pb and Zn) that had certified values. Results on the human milk samples showed that the elemental composition changed during the lactating period. Formula milks used for feeding premature babies showed important differences in essential element composition from natural milk. The elemental composition of plaque deposits in human arteries and aorta was studied using ICP-MS. In calcified plaque, Murungi et al.28 found that the molar ratio of Ca to P suggested that a significant amount existed as hydroxyapatite, but the ratio varied from sample to sample, indicating that other compounds were also present. In soft plaque, the Ca and P concentrations were an order of magnitude lower but the other elements (Al, Ba, Cu, K, Mg, Na, Pb, S, Si and Zn) were present at concentrations of the same order of magnitude as was found in calcified plaque. Comparison of the composition of plaque deposits in human bypass coronary arteries and native arteries by Thiam et al.29 showed no consistent difference. Calcium and P concentrations were relatively high in all cases, but again the ratio did not correspond to hydroxyapatite. Stadler et al.30 were more concerned about the Cu and Fe concentrations in plaque. Measurements of Cu and Fe in healthy human arteries and in carotid lesions by ICP-MS showed significantly elevated levels of Cu and Fe in the lesions. Spectra obtained by EPR were characteristic of non-haem FeIII complexes. They suggested that accumulation of Fe might contribute to the progression of cardiovascular disease. The performance of SF-ICP-MS for multielement analysis of biological tissue samples was evaluated by Engstrom et al.31 Samples were digested with HNO3 using microwave heating. Precision was better than 5% for the majority of the 68 elements and the results of analysis of CRMs were good for all elements except Cl. For elements present in concentrations above 2 mg g1, results were compared with those obtained by ICP-AES; good agreement was obtained. Trace elements in human brain tissue were determined by Gellein et al.32 using SF-ICP-MS. Amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC) were common neurodegenerative diseases in Guam in the 1950s and 1960s. Now, fortunately, these diseases are on the decline. These researchers 326 J. Anal. At. Spectrom., 2005, 20, 323–369 measured the elements Cd, Co, Cu, Fe, Mn, Rb, V and Zn in formalin-fixed brain tissue from eight Guamanian patients with ALS, four with PDC and five controls. In ALS, Cd concentrations were significantly elevated in both grey and white matter. In PDC, Zn was significantly elevated in grey matter. Other differences were found to be insignificant. As part of a study on the effect of chronic exposure to Cd on the intracellular accumulation of essential elements in cultured human intestinal cells (Caco-2 TC7), Noel et al.33 developed a rapid method using closed vessel microwave-assisted digestion and ICP-MS. Three elements, Be, In and Sc, were used as internal standards in the measurement of Ca, Cd, Cr, Cu, Mg, Mn, Mo, Na and Zn. Trueness was demonstrated by the analysis of CRMs and by comparison of results obtained for cells and CRMs with those obtained using ETAAS or FAAS. The results were in good agreement. The release of metals from metallic implants was studied by Okazaki et al.34 in a rat model. The tibia tissues near the implant were lyophilised, acid digested with microwave heating and the metals determined by ICP-MS. Iron was separately determined by ETAAS. Of the four types of alloys examined, the lowest release was from a Ti-15Zr-4Nb-4Ta alloy. 1.3.2.3 Laser ablation ICP-MS. The potential of LA-ICPMS for determination of trace elements in a gel after gel electrophoresis was explored by Chery et al.35 For the elements Ag, As, Cd, Cr, Cu, Li, Mn, Mo, Ni, Pb, Pd, Pt, Se, Tl, V and Zn, they measured LODs, repeatability and linearity. The technique was applied to the determination of selenoproteins in extracts of red blood cells after a one-dimensional (1D) separation and to a two-dimensional (2D) separation of selenoproteins in yeast. Better results were obtained by the use of a DRC to remove isobaric interferences. Of the gases tried in the cell, CO was found to give the best results. Becker et al.36 separated human brain proteins by 2D gel electrophoresis and determined Al, Cu, S, Si and Zn in the protein spots by an LA system coupled to a SF-ICP-mass spectrometer. Ion intensities for P, Si and the metals were expressed as a ratio to the S ion intensity. Laser ablation coupled to a TOF-ICP-mass spectrometer enabled Kindness et al.37 to produce 2D maps of Cu and Zn in liver sections. Use of C as an internal standard improved reproducibility. On a section of sheep liver the precision was 9–47% for Cu and 4–21% for Zn using a line scan. For a raster scan, precisions were 27–59% for Cu and 8–18% for Zn. Although the concentrations of Cu found in the sheep liver were extremely low, the distribution could be mapped. Laser ablation ICP-MS was applied by Uryu et al.38 to the determination of Pb in the tooth enamel of deciduous incisors. Pelletised bone CRMs were used as calibrants to measure the Pb : Ca ratio. The low LOD (11 mg kg1) was adequate to measure Pb concentrations found in the tooth enamel of unexposed individuals (0.1–10 mg kg1). Results obtained for Pb : Ca ratios correlated well with those obtained after digestion of tooth enamel and analysis of the digests. 1.3.2.4 Secondary ion mass spectrometry. The high sensitivity of SIMS enabled Galle et al.39 to study the removal, by the lysosomes of the proximal renal tubular cells, of elements at a much lower concentration than was possible with EPMA. Studies with EPMA required such high doses that the precipitation processes seen were possibly a consequence of the high concentrations used. They studied the elimination of Al and In from the rat kidney and found that these elements, even at ppm concentrations, were removed from the extracellular fluid by the lysosomes within a few hours. The distribution of Gd in human glioblastoma cells treated with a Gd-containing magnetic resonance imaging (MRI) agent was studied by Smith et al.40 Neutron capture therapy with 157Gd for brain tumours such as glioblastoma multiforme was being developed and the authors wished to have a technique suitable for studying the subcellular distribution of Gd. Microscopy with SIMS showed 157Gd mainly concentrated in the cytoplasm of the cell, but distributed very heterogeneously. The other six naturally abundant isotopes of Gd showed a similar distribution. The more usual isotope for neutron capture therapy is 10 B. Oyedepo et al.41 used a laboratory-made SIMS system to image cultured tumour cells incubated in media containing known 10B concentrations and intracranial tumour tissue from animals previously injected with [10B]-p-boronophenylalanine. Calibration for B in tissue standards was made by correlating the measured 10B : 12C ratio with the total B concentration measured by ICP-AES. Ion maps of 10B, 12C, 39K and 23Na and were produced. 1.3.2.5 Accelerator mass spectrometry. Using 26Al as a tracer and detection by AMS, Steinhausen et al.42 measured the absorption, distribution, speciation and excretion of Al in six healthy human volunteers. Typical absorption of Al from AlCl3 was 0.1% and, in serum, the ultrafiltrable fraction of Al was found to be 5.6%. Yumoto et al.43 found, in rat studies, that 26Al was transferred into suckling rats from maternal milk and persisted in the cerebrum, cerebellum and spinal cord long after the young rats were weaned. However, although the liver and kidney Al concentrations, as measured by AMS, increased significantly through transfer from the maternal milk, after weaning the concentrations decreased remarkably. They concluded that considerable amounts of Al taken up into the brains of the suckling rats from maternal milk remained in their brains throughout their lifetime. 1.3.3 X-ray fluorescence spectrometry 1.3.3.1 Reviews. The application of XRF in medical sciences has been reviewed by Borjesson et al.44 Recent advances in in vivo methods and their applications were detailed. 1.3.3.2 Elemental mapping. Mapping of elements in brain tissue has been carried out by microbeam SRXRF. The distribution and chemical state of Fe in substantia nigra in Parkinson’s disease were examined by SRXRF and Fe K-edge X-ray near-edge structure spectroscopy, respectively, in a study on monkey brain tissue by Ide-Ektessabi et al.45 The SRXRF mapping was carried out with a 7.16 keV beam, while the chemical state analysis was performed between 7.16 and 7.12 keV energies. The Fe21 : Fe31 ratios in the neuromelanin granule showed significant variation but correlated with the total Fe concentration. In cells having high Fe concentration most was present as Fe21. As Fe21 has been shown to promote free radical formation, this could have been a factor leading to cell death. The distribution of elements in Parkinson’s disease and amyotrophic lateral sclerosis was studied by SczerbowskaBoruchowska et al.46 A 5 by 2 mm beam scanned human brain and spinal cord tissue sections to produce 2D maps which were compared with histopathological examination. The spatial distribution of certain elements corresponded to the pattern seen under the microscope. Accumulation of elements in the nerve cell bodies and white matter was noted when the patient samples were compared with controls. Liu et al.47 compared the distribution of elements in the brains of iodine-deficient and iodine-supplemented rats. The iodine-deficient rats had higher Br, Ca, Cl and Zn and lower Cu and Fe concentrations in the cerebral cortex. The changes that occur around metallic prostheses coated with biological glasses were followed by Barbotteau et al.48 using microbeam PIXE. One type of glass disappeared after 3 months of implantation to be replaced by bony tissue. They showed that Ti release from the Al–Ti–V alloy began when the metal was exposed to biological fluids, but after a few months of implantation the Ti contamination was stabilised and remained within 30 mm of the surrounding bone. 1.3.3.3 Developments in in vivo XRF determination. The feasability of using in vivo determination of Ag in skin was examined by Graham and O’Meara.49 A 125I source was used with the detector at 901 to the source. Using silver-doped skin phantoms, 3–4 ppm of Ag could be detected in a 10–20 min detection period, which suggested that it could be used for monitoring patients for argyria, an irreversible skin pigmentation resulting from exposure to Ag. Similarly, Studinski et al.50 examined the determination of As in skin using a 109Cd source. The LODs were 3.5 and 10.3 ppm for 901 and 1801 geometries, respectively, for a measurement time of 30 min. A phantom-based feasability study was carried out by Shilstein et al.51 for the in vivo determination of Zn in prostate. Their method would allow determination through a 2–3 mm thick layer of the rectal wall using an XRF topographic technique with minimal interference from Zn in non-prostatic tissue. A special transrectal probe for this was under development. The reason for this interest is apparent from an earlier study from the same group52 in which in vitro XRF measurements were made of Zn in prostate samples taken at surgery. There was a close relationship between prostatic Zn and prostate specific antigen in blood. They believed that a combination of the two measurements would improve the separation between prostate cancer and benign prostate hyperplasia and thus allow more accurate diagnosis. The Zn concentration in prostate was not uniform so that they concluded that several measurements would need to be made at various locations. 1.3.3.4 Determination of elements in tissues by XRF. In a further publication on differences between Greenlandic Inuit and Danes, Milman et al.53 reported concentrations of Se in liver measured by XRF. The higher Se content in the Inuit (mean 26.6 mmol kg1 dry mass) than in Danes (17.7 mmol kg1) was due to a higher Se intake from fish and meat from sea mammals. Inuit men showed a negative correlation between liver Se concentration and age, whereas Danish men showed a positive correlation. There was no similar correlation for the women of both races. Concentrations of Cu, Fe and Zn in biopsy samples of the liver of patients with chronic hepatitis or hepatic cirrhosis caused by the hepatitis C virus were measured by Ebara et al.54 using PIXE. Comparison with controls showed that the only factor significantly different was the higher Cu content in the liver parenchyma. Differences in the concentrations of selected elements in primary and permanent teeth were reported by Gierat-Kucharzewska et al.55 Total reflection XRF was used to analyse the roots and crowns from the caries-affected teeth of 27 children aged from 4 to 11 y and 36 adults between the ages of 36 and 71 y. Concentrations of Cu, Mn, Pb and Sr were higher in permanent teeth than in primary teeth, while concentrations of Ca, Cr and Fe were similar. Concentrations of Ni and Zn were higher in the teeth of children than those of adults. 1.3.3.5 Determination of elements in body fluids by XRF. Total reflection XRF using the Compton peak as internal standard enabled Hernandez-Caraballo and Marco-Parra56 to measure Cu, Fe, Se and Zn in serum samples from 27 cancer patients and 33 controls. Artificial neural networks were evaluated to use the data for prediction of disease. In the cerebrospinal fluid of patients with amyotrophic lateral sclerosis, Ostachowicz et al.57 found that Cl and Zn concentrations differed significantly from those of controls. They measured Br, Ca, Cl, Cr, Cu, Fe, K, Mn, Ni, Rb and Zn by TXRF. Concentrations of Br, Ca, Cu, K, Pb, Rb, S and Zn in whole blood samples of a non-occupationally exposed population living in Mexico Valley were measured by Martinez et al.58 using TXRF. Comparison of the results with those reported for other countries showed that Ca, Cu, Pb, Rb, S and Zn concentrations were similar while Br and K were higher, possibly related to differences in diet, geography and environJ. Anal. At. Spectrom., 2005, 20, 323–369 327 mental factors. The Pb results were also covered in a separate publication.59 To improve the LOD for Pb, Fe was removed from the digested sample by extraction. The results obtained in 2001 (geometric mean: 2.00 mg dl1) were much lower than those obtained in 1980 (geometric mean: 22.2 mg dl1), reflecting a general decrease in environmental Pb exposure. Changes in Cu, Fe and Zn concentrations in the erythrocytes and serum of patients with thyroid disorders before and after 131 I therapy were studied by Zhang et al.60 using XRF. The changes seen were related to the change in the thyroid status after therapy. Both serum Cu and Zn showed a significantly positive correlation with triiodothyronine (T3) and thyroxine (T4). However, no differences were found in the erythrocyte Cu and Zn, except that erythrocyte Zn concentration showed an increase in patients with hypothyroidism and a marked negative correlation with T3 concentration. 1.3.4 Simultaneous multielement atomic absorption spectrometry. For this technique, there is a need to choose elements of relatively similar volatility, as compromise conditions will be needed for pyrolysis and atomisation. Hsiang et al.61 determined the four elements As, Co, Mn and Ni using Pd as a modifier. For the THGA, optimal compromise furnace temperatures were 1350 1C for pyrolysis and 2100 1C for atomisation. Improved recovery for As was obtained when the pyrolysis stage was split into two, the first with 5% H2–95% Ar as the internal gas and the second with pure Ar. Recoveries in urine for the four elements ranged from 88% to 95%. Trueness was confirmed by determination of the elements in the RM Seronorm Trace Elements in Urine. A W–Rh permanent chemical modifer was used by Correia and Oliveira62 in the determination of Cd and Pb in whole blood. Temperatures of 400 1C and 1500 1C for pyrolysis and atomisation were chosen. Samples were diluted 1 þ 9 with a diluent containing 0.11% m/v Triton X-100 and 1.1% v/v HNO3. Calibration by simple aqueous standard solutions was shown to be accurate and verified by analysis of three Seronorm RMs. For determination of Cd and Pb in urine,63 they used an end-capped graphite atomiser to obtain greater sensitivity (14% for Cd and 25% for Pb). Samples were diluted 1 þ 4 with a diluent containing Triton X-100, HNO3 and NH4H2PO4, the latter acting as the chemical modifier. Pyrolysis was at 500 1C and atomisation at 1800 1C. Again, calibration with simple aqueous standards was shown to be accurate. In both methods for blood and urine, furnace programme times were minimised— 63 s for blood and 57 s for urine. 1.4 Multielement studies using atomic absorption spectrometry The effect of whole body irradiation on tissue Cu, Fe, Mg, Mn and Zn concentrations was studied in a rat model by Cengiz et al.64 The results obtained on analysis of heart, lung and kidney samples by FAAS showed that Cu and Fe had significantly increased in the kidney, but there were no significant changes in the concentrations of all the elements in the heart and lung. Trace elements in pregnancy remains a popular theme for study. Awadallah et al.65 followed changes in plasma concentrations of Cu, Fe and Zn in 186 Jordanian women using measurements by FAAS. Iron concentrations remained similar in the three trimesters but plasma Cu increased and Zn decreased. In the third trimester, anaemic women (haemoglobin o11.0 g dl1) had significantly lower plasma Fe and Zn concentrations than non-anaemic women. The concentrations of Cu and Fe were significantly higher in cord blood than maternal blood, whereas the Zn concentration was lower. There was a significant positive correlation between the neonatal birth weight and the cord blood plasma Zn concentration. A further indication of concern about depletion of Zn came in a study by Cengiz et al.,66 who recommended Zn 328 J. Anal. At. Spectrom., 2005, 20, 323–369 supplementation along with folic acid in pregnancy. They studied women whose pregnancies were terminated because of foetal neural tube defects and found significantly lower serum Se and Zn concentrations than in women with normal pregnancies. Whole blood Pb and plasma Cu were higher than the controls. Copper and Zn were measured by FAAS, Pb by ETAAS and Se by HGAAS. Effects of Ca, Mg, Pb and Zn on the development of hypertension in pregnancy were studied by Magri et al.67 Comparison of results on 33 women in the third trimester of pregnancy with results from 110 normotensive pregnant women showed no difference in plasma Ca (ionised and total), Mg and Zn. Blood Pb, however, was significantly related to blood pressure, even after correcting for age and body mass index. Reduction of environmental exposure to Pb was seen as an important priority. Studies are increasing our knowledge of trace elements in cancer. Kizilay et al.68 measured concentrations of Cu, Fe, Se and Zn by AAS in acid digests of diseased larynx and skin tissues from patients with epidermoid cancer. Comparison with results from healthy tissues from patients without cancer showed that the diseased tissues had significantly lower Fe and Se concentrations. Copper and Zn concentrations were not markedly different. Interpretation of changes in plasma trace element concentrations in cancer are complicated because of the effect of the inflammatory response. Mayland et al.69 used C-reactive protein (CRP) as a marker of the inflammatory response and measured by AAS techniques, Cu, Mn, Se and Zn in the blood of 50 patients with various malignancies. Although concentrations of Se and Zn were often lower than the respective reference ranges and Cu and Mn higher than the reference range, none of these elements showed a significant correlation with CRP. The results suggest that the inflammatory response does not fully explain the reduction of Se and Zn in cancer and depletion of these elements should be considered. Infection with HIV is associated with changes in trace element concentrations. In 45 Nigerian patients diagnosed as HIV-positive, Ajayi and Omilabu70 found that the plasma Mg, Se and Zn concentrations were significantly lower than those in healthy controls and all three measurements correlated with the CD4 lymphocyte count. Copper did not show the same relationships. The authors suggested that supplementation of these patients with Mg, Se and Zn would be helpful. Analysis of pus is uncommon, but as Bryant et al.71 pointed out, knowledge of the composition of pus can help understand how the host defends itself against microbial growth. They used AAS to measure Ca, Cu, Fe, Mg and Zn and fluorimetry to measure Se in pus. Iron and Zn concentrations exceeded those in normal serum. Calcium concentrations were 2- to 3fold lower than in serum while Mg was 2- to 3-fold higher. In a study on patients with childhood asthma, Kocyigit et al.72 found increased plasma Fe and decreased plasma Se, which they thought might be responsible for the oxidant/ antioxidant imbalance in these patients. Compared with healthy controls, the patients had significantly lower plasma Mn, Se and total antioxidant capacity (TAC) and significantly higher plasma Fe and malondialdehyde concentrations. Plasma Cu, Zn and albumin concentrations did not differ significantly. Massanyi et al.73 reported concentrations of Cd, Cu, Fe, Ni, Pb and Zn in the semen of the bull, ram, boar, stallion and fox. In fact they reported it before in a publication in 2003 which was covered in last year’s Update.1 For those who are interested in repeats, rams have the highest concentrations of Cu, Fe and Pb, boars the highest Zn and bulls the highest Ni. The concentrations of Cd are similar in all species. Kosmala et al.74 believed that they might have discovered evidence that low level Cd exposure might contribute to the development of left ventricular diastolic dysfunction in patients with coronary artery disease. Using AAS techniques, they measured blood Cd and Pb, serum Cu, Se and Zn in samples from patients with indices of left ventricular diastolic dysfunction and in samples from subjects with normal coronary arteries. None of the subjects were occupationally exposed to heavy metals. The results did not show a significant difference between the two groups, but, on univariate and multivariate analysis, blood Cd significantly correlated with echocardiographic parameters of left ventricular diastolic function, mitral inflow velocity ratio and deceleration time of inflow. Other metals did not show this correlation and the correlation was absent in the control group. 1.5 Developments in single element techniques Surprisingly, there appear to have been no significant developments in novel AAS or AFS techniques as applied to clinical and biological analysis and there is nothing to report. 1.6 Hair and nail analysis Hair and nail arsenic measurements have been used in studies of high As exposure in West Bengal. Mandal et al.75 found that hair, fingernail and urine As concentrations correlated positively with water As concentration and recommended nail As as a biomarker of exposure in affected areas. Speciation of water extracts of hair and fingernails showed mainly AsIII (hair 58.9%; nail 62.4%) and AsV (hair 34.8%; nail 20.2%) with smaller amounts of MMA and DMA. Whether this reflects the speciation of As in the hair and nails is a relevant question, as the inorganic and organic As species may show different binding affinity to the proteins in hair/nails. According to Samanta et al.,76 As is not the only toxic element involved in this problem in West Bengal. Using ICP-MS, they measured ten elements in digests of hair, nails and skin scales taken from subjects in the affected area. The results showed not only high As concentrations, but also Mn, Ni and Pb concentrations higher than expected from other literature data. The use of hair and nail Cd and Pb concentrations for assessing exposure was evaluated by Mehra and Juneja.77 In occupationally exposed subjects, hair Cd and Pb concentrations ranged from 0.01 to 22.1 mg g1 and 1.02 to 409.7 mg g1 and nail Cd and Pb from 0.21 to 35.7 mg g1 and 8.13 to 765.3 mg g1, respectively. For both elements, there was a significant correlation between hair and nail levels. In a population minimally exposed to these elements, hair Cd and Pb concentrations ranged from 0.11 to 1.16 mg g1 and 0.12 to 25.16 mg g1 and nail Cd and Pb from 0.03 to 8.11 mg g1 and 1.08 to 65.6 mg g1, respectively. In this group a correlation between hair and nail levels was found for Cd, but not Pb. There were significant differences between the exposed and unexposed group for hair Pb, nail Pb, nail Cd but not hair Cd. It would have been interesting if this study had included a comparison with blood Cd and Pb concentrations. Gan et al.78 improved the sensitivity 13.4-fold in the determination of Pb in human hair by FAAS through the use of HG with K3Fe(CN)6–HCl. The LOD was 2.8 mg l1 and recovery of added Pb was in the range 96–99%. In a study of the temporal variation of blood and hair mercury concentrations in pregnancy in a population living along the St. Lawrence River in Canada, Morrissette et al.79 found that Hg exposure was related to fish consumption. However, fish on the general market as fresh, frozen or canned fish was a more important source than local fish. Blood and hair Hg concentrations, measured by CVAAS and CVAFS, respectively, correlated well with each other. Both blood and hair concentrations fell in the second and third trimester of pregnancy. The cord blood Hg concentration was significantly higher than the maternal blood Hg concentration at birth. There is not very convincing evidence that the concentrations of essential elements in hair and nails are a satisfactory measure of nutritional status, except perhaps for Se. Never- theless, many studies begin with the assumption that hair or nail measurement is a useful guide. Rush et al.80 examined whether there was seasonal variation in hair Zn concentration in an apparently well-nourished New Zealand population. Samples were washed, digested with HNO3 and Zn determined in the digest by FAAS. No seasonal variation was found and hair Zn was unrelated to hair colour, dietary variety, ethnicity and gender in this population. Changes in hair and plasma Zn during pregnancy were studied by Cavdar et al.81 using FAAS for the determination. Both plasma and hair Zn concentrations decreased significantly in the second trimester of pregnancy. Although there was a significant difference between plasma Zn in a well-nourished group and a poorly-nourished group, hair Zn concentrations were not significantly different. A study from southern Sweden82 compared the concentrations of 34 elements in the hair of 47 females living in an area with drinking water of low pH with those found in the hair of 43 females living in an area with alkaline drinking water. Measurements in hair digests and in drinking water were by ICPAES and ICP-MS. Concentrations of Ca, Fe, Mo, Se and Sr were higher in the alkaline group, while B and Ba were significantly higher in the acid group. There was a positive correlation between the hair and water concentrations for Ca, Mo, Pb and Sr. The authors concluded that this indicated the importance of intake from drinking water, but can they be right? This is the same type of water that the subjects regularly use to wash their hair and could this not just be exogenouslybound element? Lipsky et al.83 compared toenail Se concentrations in patients with prostate cancer with controls and found no significant difference. Measurements were by DRC-ICP-MS after microwave-assisted digestion of the samples. No correlation was found between nail Se and age, body mass index and smoking status. The authors questioned the protective effect of Se on prostate cancer, but perhaps they should have also questioned how reliable toenail Se concentrations were as an indicator of Se status. 1.7 Progress for individual elements 1.7.1 Aluminium. Two groups described studies on Al metabolism using 26Al tracers. Steinhausen et al.42 monitored Al absorption, distribution and excretion in six healthy volunteers and two patients with chronic renal failure, following a single administration of 26Al. Serial blood and urine samples were collected and the concentration of 26Al determined using AMS. In the same work, the time dependence of 26Al binding to low Mr serum species was also investigated. The authors reported absorption rates of the order of 103 for AlCl3 and observed differences in the rates of Al absorption and excretion between healthy volunteers and individuals with chronic renal failure. Yumoto et al.84 determined the uptake of Al from maternal milk into the brain of suckling rats using a 26Al tracer. Tissue concentrations of Al were quantitatively determined using AMS. Lactating rats were injected subcutaneously with 26 AlCl3 from day 1 to day 20 post-partum and suckling rats weaned at day 21 post-partum. Concentrations of Al in cerebrum, cerebellum, spinal cord, kidney and liver increased significantly in suckling rats between day 5 and day 20. Whilst Al concentrations in liver and kidney declined rapidly after weaning, up to 20% of the Al present in brain tissue at day 20 remained in the tissue at day 730 post-partum. The researchers concluded that a significant proportion of Al taken up in the brain of suckling rats remains in the brain throughout their lifetime. The renal handling of Al was investigated in two studies that applied particularly innovative approaches. Shirley and colleagues85 combined micropuncture sampling with ETAAS to determine Al concentrations along the renal nephron. Anaesthetised rats were infused with different doses of AlCl3 and micropuncture samples taken from the Bowman’s capsule, J. Anal. At. Spectrom., 2005, 20, 323–369 329 proximal convoluted tubule and early distal tubule for quantitative determination of Al. The authors reported that filtration into the Bowman’s capsule was significantly greater than that predicted by an in vitro model and was essentially freely filtered. They concluded that Al, when complexed with citrate, was efficiently excreted through a combination of glomerular filtration and minimal re-absorption. Galle et al.39 used SIMS to examine the subcellular localisation of Al and In in lysosomes of rat kidney proximal tubule cells. Within a few hours of administration of low physiological doses of the two elements, lysosomes had extracted the elements from the extracellular fluid and precipitated them as insoluble phosphate salts. They hypothesised that this concentration and precipitation mechanism was a physiological process rather than purely pathological process for renal handling of Al and In. Polec-Pawlak et al.86 combined both HPLC and CE with ICP-MS to investigate intracellular binding of AlIII in neuroblastoma cells incubated with aluminium lactate. They reported that exposed cells synthesised a low Mr ligand, which bound all metabolised AlIII as a negatively charged complex. The ligand could not be characterised, however, either by ES-MS or by its chromatographic behaviour. 1.7.2 Arsenic. This review period has continued to see further work on the characterisation and quantitative determination of As species and metabolites in biological matrices. B’Hymer and Caruso87 presented a comprehensive review on the application of HPLC coupled with ICP-MS for arsenic speciation in biological and environmental samples. Several groups have determined As species in human urine. The study by Sloth et al.283 determined As species in two human urine CRMs (NIES 18 and NIST2670a) and urine quality control materials. Samples were diluted 1 þ 3 v/v and As species separated by gradient chromatography on cation and anion exchange columns for quantitative determination using ICP-MS. Nine As species were determined in the urine samples. Two of these dimethylarsinoylacetic acid and trimethylarsoniopropionate were reported for the first time in human urine. The calculated sums of the individual species matched the reference value for total As in the reference materials. In an important study, Hansen and colleagues89 cautioned on the need for correct characterisation of As metabolites in urine. The authors described the generation of a sulfur containing As species when DMAV was reduced by Na2S2O5–Na2S2O3. This species could, they argued, be mistaken for the highly toxic DMAIII species. They characterised the species as dimethylarsinothioic acid by HPLC-ICP-MS coupled simultaneously to HPLC-ES-MS and ES-Q-TOF-MS and identified the species as a naturally occurring As metabolite in the urine and wool of sheep consuming high quantities of arsenosugars in a seaweed diet. In a similar vein, Lai and colleagues90 reported markedly different patterns of urinary As excretion in subjects consuming seafood. The researchers noted arsenobetaine (AB) and DMA were the major urinary As species together with a significant amount of an unknown species. They noted that two volunteers eliminated high quantities of AB even though no arsenic rich seafood had been consumed 72 h before urine sampling. They argued that a better understanding of human As metabolism is still needed. Shinohara et al.91 separated five As species, AsV, MMA, DMA, AsIII and AB from human urine using HPLC with an eluent containing 10 mM NH4NO3, 0.05% HNO3 and 0.1 mM EDTA. Three further As species, arsenocholine, TMAO and TMI were subsequently co-eluted in a single peak. The concentrations of the As species were quantitatively determined by coupling the eluent from the chromatograph directly to the nebuliser of a hexapole collision cell ICP-mass spectrometer. As with Lai and colleagues, different patterns of excretion of As species were noted by these authors which were due to different dietary habits of the 330 J. Anal. At. Spectrom., 2005, 20, 323–369 volunteers. Okina et al.92 described a method for the determination of trivalent methylated As species in rat urine using LCICP-MS. Rats were administered either DMAV or MMAV at 200 mg ml1 in drinking water. The trivalent species were extracted from the urine matrix by complexation with DDC into CCl4 and the trivalent species DMAIII and MMAIII quantitatively determined. It is pertinent to note the likely problem of using this method in many countries where restrictions have been placed on the use of CCl4. Sample digestion methods for the quantitative determination of As in blood and urine were investigated by Syaslova and Sperackova.93 For urine samples, dry ashing with Mg(NO3)2 and microwave digestion with (NH4)2S2O8 were both satisfactory for the quantitative determination of As using ETAAS. For blood samples, complete recovery of spiked As was achieved with a two-stage digestion process involving microwave digestion with HNO3–H2O2 followed by dry ashing on a hot plate. Bruhn et al.94 evaluated In, Pd and Rh as permanent chemical modifiers for the determination of As in digests of human hair and marine biological matrices using ETAAS with a tungsten coil atomiser. A 1.9-fold improvement in relative sensitivity was reported for 2 mg of Rh pre-reduced on the tungsten filament and this treatment extended the lifetime of the atomiser to 300–400 firings. An absolute LOD of 29 pg was reported and the method validated by analysing a number of CRMs. The authors used the method to monitor As concentrations in the hair of exposed workers. A very sensitive and precise method for the determination of As in microtomed cross-sections of human hair using nano-SIMS was described by Audinot and colleagues.95 The authors suggested that the method may be sufficiently sensitive to differentiate As in the medulla, cortex and cuticle and so distinguish As intoxication by ingestion from surface contamination. Whilst studies on As are normally related to the toxicity of the element, two groups reported studies on the therapeutic potential of As2O3 for treatment of solid tumours. Shen et al.96 treated esophageal carcinoma cells transplanted into immunodeficient mice with intra-tumour injections of As2O3. Concentrations of As in the tumour and other organs were determined using AAS. Levels of As remained high in the tumour tissue and were accompanied by apoptosis and necrosis of tumour cells. Arsenic was also detected in other organs but no pathological changes were observed. Kito et al.97 examined the effect of i.v. or intra-tumour administration of As2O3 on an hepatocellular carcinoma murine xenograft. Tissue concentrations of As were determined using PIXE and the authors noted that As accumulated more in the tumour than other tissues. Both groups hypothesised that intra-tumour administration of As2O3 has potential for the treatment of solid tumours. Finally, in a departure from other mass extinction hypotheses, a role for As in the mass extinction of dinosaurs was suggested by Zhou et al.98 The authors determined As in fossil skeletons of four dinosaur species using HG-AFS. Samples were digested with aqua regia in a boiling water bath and an LOD of 0.03 mg l1 was reported. The As concentrations determined were abnormally high and together with other available data supported the hypothesis for As toxicosis as a contributory factor to the mass extinction of dinosaurs in the Sichuan Province of China. 1.7.3 Bismuth. Sung and Huang11 used a laboratory-made FI system coupled to simultaneous ETAAS for the simultaneous determination of Bi, Cd and Pb in urine. Metal ions were adsorbed onto a Muromac A-1 resin micro-column and eluted directly into the graphite furnace using 20% v/v HNO3. Aqueous standard solutions taken through the same pre-concentration step were used for calibration. Reported LODs for a 213 ml sample loop were 13 ng l1, 2 ng l1 and 4.5 ng l1 for Bi, Cd and Pb, respectively. The method was validated by analysing a urine RM at two concentration levels. Determined values for the three elements were between 90% and 110% of the reference values. 1.7.4 Boron. A sensitive method for the determination of B in small volumes of undigested plasma and urine using ID-ICP-MS with DIN sample introduction was described by Bellato et al.99 One ml samples were spiked with enriched 10B solution and equilibrated for 1 h. Proteins were precipitated with HNO3 to remove interferences from C on the 11B signal. Aliquots (50 ml) of the supernatant were directly introduced into the plasma for measurement of 10B : 11B isotope ratios. An LOD of 0.6 mg l1 was reported. Total B concentrations in plasma ranged between 100 and 135 mg l1 and between 0.5 and 3.02 mg l1 in urine. Oyedepo et al.41 described the results of preliminary studies on the use of SIMS to determine 10B in cultured tumour cells incubated with p-boronophenylalanine (BPA) and in tumorous brain tissue of animals injected with BPA. Calibration was performed by analysing tissue standards and correlating the B : C ratio determined by SIMS with the total B concentration determined by ICP-AES. The researchers identified 10B hotspots in brain tissues and the intracellular localisation of 10B in cultured cells. They concluded that SIMS could show the distribution of 10B at ppm levels in cells and normal and cancerous brain tissues. Muhtaroglu100 examined the relationship between serum and urine B and bone markers in menopausal women. Serum and urine B were determined using ETAAS with a pyrolytically coated tube. Both serum and urine B levels were significantly lower in menopausal women compared with a control group. The authors hypothesised that the low levels were due to low intake of B by menopausal women. 1.7.5 Cadmium. Hernandez-Caraballo et al.101 described an extremely fast method for the direct determination of Cd in urine using ETAAS. Urine samples were diluted 1 þ 1 v/v with 4% HNO3 and 10 ml volumes injected into a transversely heated graphite atomiser pre-heated to 110 1C. The normal drying and pyrolysis steps were substituted with a 300 1C drying step and the lack of a chemical modifier other than HNO3 allowed an atomisation temperature of 1200 1C. The total thermal cycle was reduced to 42 s. An LOD of 0.12 mg l1 was reported for the optimised conditions and the method was validated by analysis of a human urine RM. A rapid method for the simultaneous determination of Cd and Pb in whole blood using ETAAS was described by Corriea et al.62 A mixture of Rh and W was used as a permanent chemical modifier, allowing compromise pyrolysis and atomisation temperatures of 400 1C and 1500 1C, respectively, and a total furnace programme time of 63 s. Blood samples were diluted 1 þ 9 v/v with 0.11% Triton X-100 and 1.1% HNO3 and calibration was performed with aqueous standards. The method was validated by analysis of whole blood CRMs and the reported LODs were 0.03 mg l1 and 0.8 mg l1 for Cd and Pb, respectively. The same workers63 also described a method for the simultaneous determination of Cd and Pb in urine using ETAAS. For this matrix, the researchers used an end-capped transversely heated atomiser and an NH4H2PO4 chemical modifier. Urine samples were diluted 1 þ 4 v/v with 0.125% Triton X-100, 2.5% HNO3 and 0.31% NH4H2PO4. Compromise pyrolysis and atomisation temperatures for quantitative determination of the two elements were 500 1C and 1800 1C, respectively. The use of an end-capped tube improved analytical sensitivities for Cd and Pb by 14% and 25%, respectively, giving reported LODs of 0.03 mg l1 for Cd and 0.57 mg l1 for Pb. Results from the analysis of a urine CRM were in good agreement with the certified value. Anthemidis and colleagues13 developed a synchronised online solvent extraction and pre-concentration system coupled with ETAAS for the determination of Cd in natural waters and urine. The Cd in the aqueous sample was chelated with ammonium diethyldithiophosphate and extracted with IBMK using a novel gravitational phase separator. An enrichment factor of 24.6 was reported giving an LOD of 2.8 ng l1. The sampling frequency was 30 h1. 1.7.6 Calcium. Many previous methods for the quantitative determination of Ca in human serum using ICP-MS have employed oxalate precipitation of Ca from the protein matrix. The reported problem with this approach is the requirement for at least 500 ml of serum. To overcome this potential problem, Chen et al.102 described a simple acid equilibration procedure in which a 20 ml serum sample was mixed with 2 ml of HNO3 and equilibrated at room temperature. The 42Ca : 43 Ca ratio in the supernatant was quantitatively determined using magnetic sector ICP-MS. The authors established the optimum acid concentration and equilibration time for accurate determination of Ca isotope ratios. The 42Ca : 43Ca ratio results obtained using this method for serum samples obtained from healthy volunteers administered enriched 42Ca were consistent with results obtained from oxalate precipitated serum samples. 1.7.7 Chromium. Cordero and colleagues12 developed a novel laboratory-built system for the on-line pre-concentration and speciation of Cr in natural waters and urine prior to quantitative determination using ETAAS. The autosampler tip was replaced with two microcolumns packed with chelating or ion-exchange resin. Control of the rotary valve, for switching columns, and the peristaltic pump were automated with an electronic control device. Using a 60 s pre-concentration time, with a sample flow rate of 2 ml min1, and a 40 ml eluent injection volume, the enrichment factors were 7.4 for CrIII and 5.6 for CrVI. The reported LODs were 0.14 mg g1 for CrIII and 0.08 mg g1 for CrVI. 1.7.8 Cobalt. Methods employing the cloud point precipitation phenomenon continue to be described for pre-concentration of trace elements for quantitative determination by AAS. Nascentes and Arruda10 described a mixed micelle extraction method in which Co was complexed with a pyridylazo compound in an aqueous Triton X-100–SDS solution and subsequently extracted into the surfactant-rich phase after phase separation by addition of HCl or NaCl. The Co concentration in this surfactant rich phase was determined using FAAS. Recoveries from spiked solutions were 98–102%. With HCl as the phase separating electrolyte the reported LOD was 1.1 mg l1, whilst with NaCl the LOD was 1.6 mg l1. The method was used to determine Co concentrations in pharmaceutical preparations. Gopikrishna et al.9 described a method for the quantitative determination of Co and Ni in hair samples using FAAS. To eliminate matrix interferences and improve analytical sensitivity, the elements were extracted and pre-concentrated from the hair matrix by complexation with ethyl xanthate on benzophenone at pH 8–10. The solid complexes were dissolved in 5 ml of DMF and the solution introduced into the nebuliser of the flame spectrometer for determination of Co and Ni. The method was validated by analysis of two hair CRMs and the results obtained were in good agreement with the certified values. The method was used by the authors to examine Co and Ni concentrations in hair samples from inhabitants of different Indian states. Following on from earlier volunteer studies demonstrating skin absorption of Co powder, Filon and colleagues103 described findings from an interesting series of experiments to investigate the mechanisms for in vitro percutaneous absorption of Co. Skin permeation was calculated using the Franz J. Anal. At. Spectrom., 2005, 20, 323–369 331 diffusion cell method with the Co powder suspended in a synthetic sweat solution and a physiological solution as the receptor phase. Concentrations of Co in the receptor solution were determined using ETAAS, whilst ionic Co21 in both donor and receptor phases was determined using differentialpulse polarography. The researchers calculated a steady state permeation rate of 0.0123 mg cm2 h1 with a lag time of 1.55 h. They concluded that Co powder was oxidised in the sweat solution and that the Co21 ions readily permeated across the skin. Brodner et al.104 reported findings of a study of serum Co levels in patients one to five years after metal-on-metal total hip arthoplasty. Serum Co levels were determined using AAS. Median serum Co levels were 1 mg l1 one year following surgery and fell marginally to 0.7 mg l1 after 5 years. The researchers concluded that there was systematic release of Co from metal-on-metal articulation throughout the study period but concentrations remained in a constant range and did not reflect a run-in wear period for such articulations. Faccioni et al.105 investigated in vivo metal release from fixed orthodontic appliances. Mucosal cells were collected from the cheeks of orthodontic patients and control subjects and the cellular concentrations of Co and Ni quantitatively determined using ICP-MS. Intracellular concentrations of Co and Ni were 2.4fold and 3.8-fold higher, respectively, in orthodontic patients compared with controls. Cell viability was lower and DNA damage, as assessed by the alkali comet assay, was higher in the orthodontic patients. Significant positive correlations were found between cellular Co and Ni levels and the number of comet cells. The authors hypothesised that the release of Co and Ni from orthodontic appliances could induce DNA damage in oral mucosa cells. 1.7.9 Copper. Shamsipur et al.8 described a rapid and simple method for the determination of ultra-trace concentrations of Cu in aqueous biological samples using AAS. Copper was quantitatively and selectively extracted from aqueous samples and digests by adsorption onto a C18 membrane disk modified with a novel anthraquinone derivative. The adsorbed Cu was then eluted with a minimal volume of HNO3. An enrichment factor of 400 was reported giving an LOD of 100 ng l1. The method was validated by analysing a number of biological CRMs. Determination of the ratio of free and protein-bound serum Cu is one of a number of preliminary tests for diagnosis of Wilson’s disease. Bohrer and colleagues106 compared two alternative approaches for the determination of free and protein-bound serum Cu. One approach used a small column packed with polyethylene powder for the solid-phase extraction of protein-bound Cu. Satisfactory adsorption and elution were achieved using Mg(NO3)2 as carrier solution and CH3OH as eluent. Copper in the column effluent (unbound fraction) and eluate (protein-bound fraction) were quantitatively determined using ETAAS. The second method employed simple ultra-filtration with a 20 kDa cut-off. Total plasma Cu and ultra-filtrate Cu concentrations were determined and the protein-bound fraction calculated by simple subtraction of ultrafiltrate Cu from total Cu. Analysis of serum samples from 10 individuals gave comparable results using the two approaches. With the growing accessibility of multi-element spectrometric techniques, researchers are focusing more on combinations of elements rather than single element studies. Kindness et al.37 examined the application of LA-ICP-MS for 2D mapping of Cu and Zn in liver. Line scans and 2D maps of thin sections of sheep liver revealed zoning of Cu in the tissue. The authors concluded that the precision of the ablation method was sufficient to identify non-uniform distributions and changes in elemental concentrations in tissue sections. The involvement of Cu and other transition metals in a range of diseases has been investigated and discussed in this 332 J. Anal. At. Spectrom., 2005, 20, 323–369 review period. Stadler et al.30 examined the controversial involvement of transition elements in atherosclerosis. The researchers employed minimally invasive techniques to avoid disruption of metal–protein interactions. EPR spectroscopy and ICP-MS were used to quantitatively determine Cu and Fe in ex vivo healthy human arteries and carotid lesions. They determined significantly elevated levels of both Cu (7.5 pmol mg1 versus 2 pmol mg1) and Fe (0.53 nmol mg1 versus 0.17 nmol mg1) in lesions compared with healthy tissue. Topuzoglu et al.107 compared the concentrations of Cu, Mg and Zn in serum samples from patients with dilated cardiomyopathy using AAS. They observed that patients with the disease had raised serum Cu levels and lower serum Zn levels compared with healthy controls but found no significant differences in serum Mg between the two groups. Domellof et al.108 investigated the relationship between maternal mineral status and the concentrations of Cu and Zn in human milk. Concentrations of the elements in plasma and milk samples collected from Honduran and Swedish women were quantitatively determined using AAS. Mean milk concentrations of Cu and Zn were higher in Honduran women compared with Swedish women (0.16 mg l1 versus 0.12 mg l1 for Cu and 0.7 mg l1 versus 0.46 mg l1 for Zn). Milk Cu and Zn concentrations were not significantly correlated with maternal plasma concentrations of the elements and the authors concluded that milk concentrations of the elements are not associated with maternal mineral status, indicating an active transport mechanism in the mammary gland for these elements. 1.7.10 Gadolinium. Neutron capture therapy (NCT) with Gd for the treatment of certain brain tumours has recently gained some attention. Smith and colleagues40 used SIMS ion microscopy to undertake subcellular imaging of 157Gd in a human glioblastoma cell line incubated with 25 mg ml1 Gd– DTPA, an MRI contrast enhancing agent. The researchers determined the intracellular distribution of 157Gd and the six other naturally occurring Gd isotopes. Gadolinium was heterogeneously distributed in the cells and nuclear Gd was significantly lower than cytosolic Gd. They considered that SIMS offered an important role in the development and validation of Gd containing NCT drugs and new MRI imaging agents. 157 1.7.11 Gold. Higginbotham and colleagues109 investigated the tolerance and pharmacokinetics of a novel chemotherapeutic agent tetrakis(trishydroxymethyl)phosphinegold(I) chloride (MU-Gold) in dogs. Levels of Au in the serum of dogs administered MU-Gold (10 mg kg1) intravenously were determined using AAS. Serum Au levels between 10 and 50 mg ml1 were determined with no observed clinical toxicities. A two-compartment model with elimination half-life of 40 h and mean volume of distribution of 0.66 kg was developed to describe the pharmacokinetics of the compound. 1.7.12 Iron. Ohno et al.110 determined 56Fe : 54Fe and Fe : 54Fe isotope ratios in human erythrocytes using multicollector ICP-MS. To eliminate non-mass spectrometric interferences on the measured ratios, the Fe ions were separated from the organic matrix and major elements using ion chromatography. The ArO and ArOH interferences on the 56Fe and 57Fe isotopes were minimised by operating a dry plasma with a desolvation nebulizer for sample introduction. The precision of the ratio measurements was sufficient to monitor natural variations in Fe isotope ratios. The authors used the method to examine the seasonal variation of Fe isotope ratios in human volunteers over 12 months. They reported no significant seasonal changes in Fe ratios, which they hypothesised was due to the small contribution of daily Fe intake (1 mg) on the total body content of Fe (2–4 g). They did note, however, 57 that Fe isotope ratios in the female volunteer were different from the mean of the male volunteers, which they hypothesised may be due to differences in the efficiency of Fe uptake from the diet. Jin111 also described work on the determination of Fe isotope ratios using ICP-MS for iron nutritional studies. This researcher used double focusing ICP-MS to determine 54Fe : 56 Fe, 57Fe : 56Fe and 58Fe : 56Fe isotope ratios in food samples and human faeces. Argon oxide interferences on the 54 Fe and 56Fe masses were overcome by operating the instrument in a high resolution mode. Several studies have examined Fe status in patients with various diseases. Leveque and colleagues112 examined levels of Fe and ascorbic acid in dermis from healthy individuals and individuals with psoriasis. The Fe and ascorbic acid concentrations were determined in micro-dialysates from healthy and psoriatic dermis using AAS and GC-MS, respectively. Levels of Fe in ‘involved’ psoriatic dermis (57 mg l1) and ‘uninvolved’ psoriatic dermis (49 mg l1) were significantly higher than in healthy dermis (21.8 mg l1), whilst ascorbic acid levels in both psoriatic tissue types were significantly lower than in healthy dermis. Kucharzewski et al.113 investigated Fe levels in serum and tissue of patients with colorectal cancer, patients with colon and rectal polyps and healthy individuals. Serum and tissue Fe levels were determined using TXRF. The mean serum Fe level in colorectal cancer patients was significantly lower (54.5 mg g1) compared with patients with polyps (91.3 mg g1) and control subjects (108 mg g1), a pattern that was also reflected by serum ferritin but not by albumin or haemoglobin. Finally, in studies to examine the potential role of Fe species in Parkinson’s disease, Ide-Ektessabi et al.45 examined the distribution of Fe in the substantia nigra region of the brain of monkeys injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Elemental mapping was performed using SR-XRF and X-ray absorption near edge structure (XANES). Powders of FeO (Fe21) and Fe2O3 (Fe31) were used as reference samples for XANES measurements. The researchers noted that cells with a high Fe content had high levels of Fe21 ions and hypothesised that the greater potential for this species to generate free radicals may be a contributory factor to oxidative stress and cell death. 1.7.13 Lead. Reported studies on Pb have declined significantly in this review period as more attention is focused on multi-element studies. The introduction of standards and guidelines on uncertainty estimates for analytical measurements has resulted in more attention being paid by laboratories to the calculation and reporting of uncertainty with their analytical results. Patriarca and colleagues114 published a comprehensive and informative working example for estimation of uncertainty of blood Pb determination using ETAAS, based on the EURACHEM/CITAC guidelines. Blood samples were diluted 1 þ 1 v/v with 0.2% Triton-X100 and injected with NH4H2PO4 (5 g l1) and Mg(NO3)2 (0.5 g l1) chemical modifiers. Matrix matched standards were used for calibration. Trueness of analytical results was assessed by analysis of CRMs and by comparison with target values for other blood reference materials. The expanded uncertainty for blood Pb measurements ranged from 16% to 20% depending on the blood Pb concentration. Groups continue to investigate alternatives to venous blood samples for the biological monitoring of occupational Pb exposure but still reach the same conclusions as pioneering researchers over 30 years ago. Taylor et al.115 examined the use of capillary earlobe blood samples for biological monitoring of Pb. Both earlobe and venous blood samples were taken from exposed workers and the Pb concentrations determined using ETAAS. A mean difference of 38 mg dl1 was found between earlobe and venous blood samples taken from the same individual and more than 50% of earlobe samples had Pb levels more than twice the level in the corresponding venous sample. These enormous differences clearly highlight the contamination risks associated with biological monitoring if sampling is not appropriately controlled. The authors reported that 54% of workers surveyed preferred earlobe sampling. However, considering the biological monitoring action level for blood lead is between 50 mg dl1 and 70 mg dl1 for many countries, it would be interesting to note what the response might be if told that earlobe sampling gave a 50% chance of a false result which might lead to suspension from work. The authors rightly concluded that earlobe sampling was still not appropriate for biological monitoring of Pb exposure. Studies continue to examine body burdens of Pb and the monitoring of continuing falls in environmental Pb exposures. The well recognised relationship between body Fe burden and Pb absorption led Wright and colleagues116 to investigate whether the haemochromatosis genotypes C282Y or H63D (HFE variants) were associated with body Pb burden in elderly men. Volunteers from a national ageing study were genotyped for the two HFE variants and patella and tibia Pb levels determined using K-XRF. Multivariate linear regression models were constructed to adjust for age, smoking and education. The adjusted data showed that elderly men with the HFE variants had lower patella Pb levels and suggested that alterations in Pb toxicokinetics may be mediated by Fe metabolic pathways regulated by HFE gene products. Dorea117 produced a comprehensive review on environmental exposure to Hg and Pb and the transfer of these elements from mother to foetus and infant. The review concluded that diets consumed by lactating mothers pose no significant health hazards to breast-fed infants but that formula feeds based on cow’s milk posed a greater risk of infant exposure. Ettinger et al.118 also investigated the relationship between maternal bone Pb stores and concentrations of Pb in human milk through a large scale study of women in Mexico City. The concentrations of Pb in umbilical and maternal blood were determined in 310 women at the time of delivery. Subsequently, levels of Pb in human milk, blood and patella and tibia bone were determined in the same women one month post-partum. Levels of Pb in human milk ranged from 0.21 to 8.02 mg l1 (geometric mean 1.1 mg l1) and blood Pb levels ranged from 1.8 to 29.9 mg dl1 (geometric mean 8.4 mg dl1). The researchers determined statistically significant relationships between human milk Pb and umbilical Pb, with maternal blood Pb at delivery and one month post partum and with patella Pb. However, maternal age, length of residence in Mexico City and use of lead glazed ceramics were not significant predictors of human milk Pb. They estimated that a 5 mg dl1 increase in maternal blood Pb was associated with a 33% increase in human milk Pb and that a 20 mg g1 increase in patella Pb with a 14% increase in human milk Pb. They concluded that human milk Pb levels were influenced by both current and past Pb exposure. Martinez et al.59 determined blood Pb levels in a randomly sampled population from the Mexico Valley. Blood samples were acid digested and Fe extracted with IBMK to improve the analytical sensitivity for determination of Pb using TXRF. The authors reported a mean blood Pb level of 2 mg dl1 compared with a mean value of 22 mg dl1 determined for a similar population in 1980. Soldin and colleagues119 also reported a significant decline in blood Pb levels in a large paediatric population from the Washington DC area. A median blood Pb level of 3.3 mg dl1 was reported which was significantly lower than levels determined for a similar population in 1991. There is significant supporting data from other studies to show that these are genuine declines in environmental exposure rather than improvements in analytical techniques. Finally, two groups described methods to determine the Pb content of tooth enamel. Uryu et al.38 determined the Pb : Ca ratio in the enamel of deciduous teeth using LA-ICP-MS. A pelletised bone CRM was used as a single point calibrant and J. Anal. At. Spectrom., 2005, 20, 323–369 333 the reported LOD was 11 mg kg1. The authors considered the method to be of value for the assessment of in utero Pb exposure. Gomes et al.120 took superficial enamel biopsies from deciduous teeth for quantitative determination of Pb using ETAAS. The enamel biopsies were taken from four to five year olds living in industrial and suburban areas of Piracicaba City, Brazil. The researchers established that biopsy depths greater than 3.9 mm gave the most reproducible results. Enamel Pb concentrations in children from industrial areas (169 mg g1) were significantly higher than those from children in non-industrial areas (118 mg g1). 1.7.14 Lithium. The narrow therapeutic range of Li for treatment of depressive disorders requires regular monitoring of plasma Li levels in patients on such medication. To test the hypothesis that the Li concentration in erythrocytes is a better indicator of brain Li levels, Camus et al.121 compared Li concentrations in plasma, erythrocytes and the calculated ratio (LiR) in patients classified into three groups: therapeutic drug monitoring, acute intoxication and acute-on-chronic intoxication. Plasma and erythrocyte Li concentrations were determined using AAS. The researchers found a good correlation between plasma and erythrocyte Li concentrations (r ¼ 0.81). They also reported that plasma Li was more elevated in cases of acute intoxication whilst Li accumulated preferentially in erythrocytes in acute-on-chronic intoxication. They concluded that measurement of both plasma and erythrocyte Li and the calculated ration LiR may be sensitive markers of Li intoxication. 1.7.15 Magnesium. Bohn and colleagues122 investigated the merits of determining Mg in urine and erythrocytes to monitor Mg absorption as alternatives to the conventional method of faecal Mg measurement. Ten volunteers were given 2.2 nmol of 25 Mg in water, together with bread, followed by an i.v. injection of 0.6 nmol 26Mg. Urine and faeces were collected for 6 days and a blood sample taken on day 14 following administration of the Mg isotopes. Isotope ratios were determined in urine and faecal samples using TIMS and in erythrocytes using ICP-MS. Determination of Mg absorption was based on either six day or 24 h urine pools, six day faecal pools or a single blood sample taken 14 days after intake of Mg isotopes. The researchers found no significant differences in the mean Mg absorption (42%) determined by the different measurement approaches except when based on a six day urine pool, when the calculated absorption figure was 33%. They concluded that Mg absorption can be accurately determined from 24 h pooled urine samples or a single blood sample as alternatives to faecal monitoring. 1.7.16 Manganese. Speciation of Mn in human milk was comprehensively studied by Michalke and Schramel123 using both ICP-AES and ICP-MS. In a preliminary investigation, human milk was centrifuged and the Mn content of the supernatant and pelleted fraction determined using ICP-AES. The total concentration of Mn in the defatted milk fraction was 2.85 mg l1 and the Mn concentrations in the low Mr supernatant and pelleted fractions were 2.6 mg l1 and 0.25 mg l1, respectively. The defatted milk fraction was further investigated by on-line coupling of SEC and anion exchange chromatography to ICP-MS. Manganese was predominantly associated with low Mr species, with masses around 300 Da. Inorganic Mn and Mn–citrate complexes were positively identified. Other low Mr species were found but could not be characterised. Whilst studies show increased risks of pneumoconiosis and other respiratory diseases related to exposures to welding fumes, manganism resulting from exposure to welding fume is still something of a controversial issue. Yu et al.124 investigated the 334 J. Anal. At. Spectrom., 2005, 20, 323–369 distribution of Mn in brain tissue of rats exposed to welding fumes generated from manual metal-arc stainless steel. Rats were exposed to fumes containing either 1.6 mg m3 Mn or 3.5 mg m3 Mn for 2 h per day over a 60-day period. Concentrations of Mn in blood, brain, lung and liver were determined using AAS. Dose and time dependent increases in liver and lung Mn were reported but only slight increases in blood Mn were observed. Statistically significant increases in the Mn content of brain cerebellum were also reported together with slight increases in Mn concentrations in the substantia nigra and basal, temporal and frontal cortex. The authors concluded that the tissue distribution of Mn derived from welding fume was different from that resulting from dietary manganese exposures. 1.7.17 Mercury. The contribution of dental amalgam to an individuals Hg body burden continues to be investigated. Two groups examined exposure to Hg from amalgam fillings. Halbach and Welz125 described a novel method for the real-time direct determination of Hg in intra oral vapour using AAS with Zeeman effect background correction. Intra oral air was aspirated through a disposable mouthpiece and pumped to the spectrometer using computer-controlled valves and a programmable timer. The researchers adapted the system to investigate the emission of Hg from amalgam in situ and from amalgam samples in vitro. A series of measurements on an individual volunteer gave a coefficient of variation between 18% and 25% and the method was sufficiently sensitive to measure a significant increase in the emission of Hg following insertion of new fillings. Hansen et al.126 developed a standardised procedure for evaluating the Hg exposure of individuals with amalgam fillings and monitored over 2000 patients to establish a reference database to act as a diagnostic tool. The researchers quantitatively determined Hg in scalp hair and urine, before and after administration of dimercaptopropane sulfonate (DMPS), using AAS. Release of Hg from dental amalgam was monitored by a chew test with quantitative determination of Hg in the chewing gum. The reported 50th percentiles were 1.3 mg g1 creatinine in basal urine, 32 mg g1 creatinine after administration of DMPS and 454 ng g1 in hair. The measured concentrations in the chewing gum were reported to correspond to a release of 1 mg Hg per minute of chewing. Several groups have described methods for the determination of total Hg in different biological matrices. Anthemidis et al.21 developed a method for the determination of trace levels of Hg in a variety of biological matrices using on-line micro-column pre-concentration coupled with CV-ICP-AES. Mercury in acid digested samples was complexed with APDC and adsorbed onto fine PTFE turnings packed in the lower compartment of a combined pre-concentration column and gas–liquid separator. The mercury was subsequently released from the PTFE as vapour by reduction with SnCl2 and pumped directly from the gas–liquid separator into the plasma. Using a 60 s pre-concentration step, the authors reported an LOD of 0.01 mg l1. The method was validated by analysing a marine CRM (BCR CRM 278). Barbosa et al.349 described an improved method for the determination of Hg in whole blood, which eliminated on-line microwave digestion and overcame the problem of protein precipitation and resulting high back pressure associated with this approach. Blood samples (300 ml) were mixed with an equal volume of 10% TMAH and incubated at room temperature for one hour. The samples were further diluted 1 þ 4 v/v with 2% HCl for quantitative determination using FI-CV-AAS. The method was validated by analysing whole blood CRMs and samples from a proficiency testing scheme. The reported LOD was 0.2 mg l1. Methods for the quantitative determination of methylmercury in biological matrices were described by two research groups. Chen et al.127 determined methylmercury in fish tissue using GC-MS, following derivatisation of the methylmercury with Cu21 and sodium tetrapropylborate. Tissue samples were microwave digested with alkaline TMAH for derivatisation of Hg and extraction into n-heptane. The extracted derivative was injected and adsorbed in the splitless injection port of the gas chromatograph. The method was validated by analysing three marine tissue CRMs and the results obtained were in good agreement with the certified values. Montuori et al.128 established the optimised digestion conditions for human hair samples in order to minimise the degradation of methylmercury prior to aqueous phase ethylation and quantitative determination of methylmercury using GC-CVAFS. Clough and colleagues129 determined the concentrations of inorganic Hg and methylmercury in two CRMs using ID-SF-ICP-MS for quantitative determination of the mass fraction of Hg in NIST 2710 and HPLC coupled with ID-ICP-MS for quantitative determination of the mass fraction of methylmercury in DORM-2. The researchers examined the temporal equilibration of the ID spike by monitoring the 200Hg : 199Hg ratio. Complete equilibration in the NIST CRM was only achieved with microwave digestion using 10% HNO3. For the DORM-2 CRM, complete equilibration was achieved with a 50 : 50 H2O : CH3OH solvent containing 0.01% mercaptoethanol. The researchers also calculated uncertainty budgets for each of the quantitative determinations. Morrissette et al.79 studied the temporal variations of blood and hair Hg concentrations in pregnant women living along the St. Lawrence river. The authors recruited 159 pregnant volunteers, who completed detailed questionnaires on fish consumption before and during pregnancy. Blood samples were taken in the three trimester periods and a further blood and hair sample taken at the time of delivery. Blood Hg was determined using CVAAS and hair Hg using CVAFS. Both blood and hair Hg levels increased during the second and third trimester. Cord blood Hg was higher than maternal blood Hg at birth and a strong correlation was observed between the frequency of fish consumption and Hg concentrations in mothers and their newborn. Multivariate analysis showed that market and frozen fish was a more important contributor to body burden of Hg than local fish from the St Lawrence river. 1.7.18 Molybdenum. Turnlund and Keyes130 investigated the effect of dietary Mo intake on plasma Mo levels using ICP-MS. Twelve male volunteers were put on a low Mo (22 mg d1) diet for 24 days, after which they were divided into different study groups and administered different regimes of low and high daily dietary Mo intake. During the intial 24 day period on low Mo intake, the mean plasma Mo concentration fell from 8.2 nmol l1 to 5.1 nmol l1 at day 24. Subsequently the plasma Mo concentration reflected the low and high dietary intake within 14 days of a change in Mo intake. The study was performed so as to obtain data, from which, dietary intake recommendations could be made. 1.7.19 Nickel. The speciation of Ni in tissue extracts from healthy and cancerous colon tissue was investigated by Bouyssiere and colleagues.131 Sequential anion exchange chromatography and SEC, coupled with SF-ICP-MS, resolved and quantitatively determined several nickel-binding biomolecules from the tissue extracts. No significant differences in the pattern of Ni species were found between the cancerous and normal tissue. A similar study to that described earlier in the section on cobalt was undertaken by Eliades et al.132 who investigated the cytotoxicity of ions released from nickel–titanium and stainless steel orthodontic alloys. Full sets of stainless steel orthodontic brackets and nickel–titanium wires were incubated in 0.9% saline for one month. Concentrations of elemental ions released into the incubation solution were quantitatively deter- mined using ICP-MS. Cytotoxicity of the incubation medium was assessed using periodontal and gingival fibroblasts. No measurable release of ions was observed with the nickel– titanium wires, but Cr and Ni were quantitatively determined in the stainless steel incubation medium. Neither of the two incubation media had any cytotoxic effect on the fibroblast cell lines. 1.7.20 Phosphorus. Innovative uses of DRC-ICP-MS have been published in this review period. Bandura et al.133 determined P and S, as PO1 and SO1, in cell culture digests using ICP-DRC-MS with O2 as the reaction gas in the DRC. The reported sensitivity allowed the determination of pmol ml1 concentrations of phospho-proteins using S as an internal standard. The method was used to examine P : S ratios in cell cultures from malignant and non-malignant cell lines. The researchers reported that the PO1 : SO1 ratio in human colorectal adenocarcinoma cells was 1.75 times higher than in normal tissue from the same patient. In the same paper, the researchers described the quantitative determination of the phospho-protein phosvitin at nanomolar levels in 1D polyacrylamide gels using LA-ICP-MS. Becker et al.36 also used LA-ICP-MS to determine P, S and metal elements in human brain proteins separated by 2D gel electrophoresis. Quantitative determination of the elements in single protein spots was achieved using a SF-ICP-mass spectrometer. 1.7.21 Platinum and noble metals. In previous ASU reviews, the large proportion of papers on the determination of Pt in biological matrices has been related to studies on Pt based anticancer drugs. This review period has seen growing interest in the assessment of environmental exposures to platinum group elements (PGEs). Zaray and colleagues134 determined Pt in urine samples collected from 100 adults living in the city centres of Budapest and Vienna. Urine samples were simply diluted 1 þ 9 v/v with distilled H2O for quantitative determination of Pt using HR-ICP-MS. Particulate air samples were also collected from the two city centres. The polycarbonate filters were acid digested in a microwave digestion system for determination of Pt, also using high resolution ICP-MS. Mean concentrations of Pt in residents of Budapest were about three times greater than levels in the Vienna residents. This difference was reflected in the concentrations of Pt in the respirable fraction of the aerosol samples collected from the two city centres. Bocca et al.135 presented the findings of a comprehensive study of environmental exposure to platinum group elements (PGEs) in the Italian population. Urine samples were collected from 257 adult residents from two representative cities, one a small urban environment characterised by low traffic density (Foligno) the other a large city with constant high traffic density (Rome). Urine samples were diluted 1 þ 4 v/v and PGEs determined using SF-ICP-MS. The researchers found significant differences in the concentrations of Pt and Rh between the two populations. The ranges of urine Pt and Rh levels in the Foligno population were 0.24 to 3.08 ng l1 and 0.53 to 14.8 ng l1, respectively, compared with ranges of 0.49 to 8.31 ng l1 for Pt and 4.1 to 38.6 ng l1 for Rh in the Rome population. The same group of researchers136 monitored exposure to airborne Pt in traffic officers from the Rome City police force. Urine samples were collected from 103 traffic officers and a control group of 58 office workers. Urine concentrations of Pt were quantitatively determined using SF-ICP-MS. Although the Pt concentrations determined were higher than values reported for other urban populations, the researchers found no difference in urine Pt levels between the traffic officers (4.45 ng l1) and the office workers (4.56 ng l1). Bettinelli et al.137 presented a method for the quantitative determination of Pt in biological fluids using ICP-MS in which J. Anal. At. Spectrom., 2005, 20, 323–369 335 the analytical uncertainty for Pt determination in different matrices was assessed using the EURACHEM/CITAC guidelines. The researchers reported LOQs of 1 mg l1 for plasma, 0.1 mg l1 for plasma ultra-filtrate and 2 mg l1 for urine matrices. They argued that the estimation of uncertainty of measurements of Pt in clinical samples had important implications when used to interpret the pharmacokinetics and optimised therapy regimes for Pt anticancer agents. Fan and colleagues138 described a novel method for the quantitative determination of PGEs in biological and environmental samples using ETV-ICP-MS. The elements were separated from the sample matrix by chelation with DDC. Using a low vaporisation temperature of 1100 1C, PdII, PtII and RhIII were introduced into the plasma as the gaseous dithiocarbamate complexes. With optimised conditions for complexation and thermal treatment, the authors reported LODs of 1.4 ng ml1, 5.4 ng ml1 and 0.8 ng ml1 for Pd, Pt and Rh, respectively. Zimmermann et al.139 evaluated a method for the quantitative determination of ultra-trace concentrations of PGEs in small quantities of biological tissue using ETAAS following microwave digestion of the tissue samples. Tissue samples were obtained from mussels experimentally exposed to PGE salts and ground automobile catalytic converter material. Reported LODs ranged from 13 ng g1 for Rh to 270 ng g1 for Pt. The authors compared this method with reference methods using high pressure ashing and CSV for Pt and Rh and TXRF after co-precipitation with mercury for Pd. They concluded that ETAAS was sufficiently sensitive for routine analysis of tissue samples with concentrations of PGEs in the upper ng g1 range. Several groups have described pharmacokinetic studies on platinum based anticancer drugs. Hann and colleagues140 determined cisplatin and its degradation products mono- and di-aquacisplatin in aqueous solutions and urine samples using HPLC coupled with ICP-MS. The researchers established the degredation kinetics of cisplatin in aqueous solutions of different Cl concentrations. They reported that no equilibration was established between cisplatin and its products, which decayed after several hours. The urine samples contained a large fraction of mono-aquacisplatin and several uncharacterised Pt species. Warren et al.141 determined the pharmacokinetics of carboplatin when administered in combination with lobradimil to paediatric patients with brain tumours. Carboplatin was administered at a dose rate to achieve target areaunder-the curve (AUC) concentrations of 3.5 mg min ml1. Plasma ultrafiltrate Pt was determined using AAS and the AUC derived. The authors observed that the measured AUC exceeded the target AUC in all patients by a median value of 35%, and they concluded that the failure of adaptive dosage of carboplatin with lobradimil to meet the target AUC concentration was due to an unexpected drug interaction. Ghezzi et al.142 investigated the intracellular uptake and accumulation of Pt in a breast cancer cell line (MCF-7) using ICP-MS. Cultured cells were incubated with cisplatin, carboplatin and oxaliplatin. The results led the authors to hypothesise a passive diffusion mechanism for cellular uptake. Hagrman and colleagues143 studied the binding of Pt drugs to glutathione in conditions mimicking the cell cytosol. The reactions were monitored by UV spectroscopy and HPLC coupled with AAS. The authors derived first order reaction kinetics for different Pt compounds, noting that the reaction of carboplatin with GSH was 32 times slower than for oxaliplatin and 23 times slower than that for cisplatin. 1.7.22 Selenium. Different sample preparation methods for the determination of Se in plasma using magnetic sector ICP-MS were examined by Featherstone and colleagues.144 The authors reported the most suitable method to be a 1 þ 9 v/v dilution of plasma using 0.5% v/v CH3CH2OH with an internal standard 336 J. Anal. At. Spectrom., 2005, 20, 323–369 of In or Sc. Interference from 40Ar37Cl precluded the quantitative determination of Se based on the measurement of 77Se in low resolution mode and reliable results were only achieved with measurement of the 82Se isotope in high resolution mode. The authors used the method to determine Se in plasma samples from a healthy population and a mean plasma Se concentration of 102 mg l1 was reported. The stability of Se in plasma samples was investigated by Sabe et al.145 The authors compared two calibration methods: matrix matching and standard additions. They found significant differences in the measured plasma Se concentrations using the two calibration procedures. They established that plasma Se levels remained stable for up to one year when stored at 20 1C. Mazej et al.146 determined Se in human milk using HGAFS. Satisfactory digestion of the sample matrix was achieved with H2SO4– HNO3–H2O2 and the method was sufficiently sensitive for quantitative determination of Se in a 1 ml sample volume. An LOD of 0.25 ng g1 was reported and a mean Se concentration of 12 ng g1 was found in milk samples from healthy lactating women in North Eastern Italy. The same group147 also used HGAFS to determine Se in digests of water soluble proteins and peptides. Protein solutions were digested with HNO3–H2O2 and an LOD of 0.2 ng g1 was reported. Chery et al.35 presented a comprehensive and systematic study on the quantitative determination of metalloproteins using LA-ICPMS, following separation of proteins by polyacrylamide gel electrophoresis (PAGE). The researchers used this approach to determine yeast extract selenoproteins separated by 2D PAGE and selenoproteins from erythrocyte extracts after 1D separation by PAGE. The use of a DRC with CO or He as reaction gas eliminated interferences on the most abundant 80Se isotope and gave reported LODs of 0.07 mg g1 for single hole ablation and 0.15 mg g1 for translational ablation. In common with recent past reviews, much of the work on Se this period has focused on Se speciation. Huerta et al.148 described two sample preparation methods for the characterisation of Se species in urine using ES-MS-MS. The selenocompounds were separated from the urine matrix and preconcentrated by sequential steps of SEC, reversed-phase HPLC and freeze-drying. The authors used the method to characterise Se-methyl-N-selenohexosamine in urine from rats administered selenomethionine. Gammelgaard and Bendahl149 separated ten Se species from urine samples collected from two volunteers consuming selenised yeast. Urine samples were pre-concentrated up to 100fold by evaporation under N2 and CH3OH extraction. The Se species were separated by reversed-phase and ion-pair chromatography for quantitative determination using ICP-MS. Eluent from the chromatograph was introduced into the plasma through a micro-concentric nebuliser or DIN, for samples with high concentrations of dissolved solids. Only two Se species were characterised. The major urine species was Se-methylacetylgalactosamine, whilst Se-methyl-N-acetylglucosamine was a minor constituent present at a concentration less than 2% of the acetylgalactosamine species. In a subsequent report,150 the same researchers characterised a third urinary Se metabolite using nano-ES-MS. Basal urine samples from volunteers not given Se supplements were lyophilised and Se species extracted with CH3OH for separation and pre-concentration using reversed-phase HPLC and SEC. In addition to the two Se species reported in the previous paper, the authors identified Se-methylselenogalactosamine. This species was present in higher concentrations than Semethyl-N-acetylgalactosamine and led the authors to hypothesise that this may be the main urinary metabolite in basal urine. Braga and colleagues151 investigated the in vitro reaction of selenite with plasma thiol compounds glutathione, cysteine and homocysteine. The reaction products were characterised using HPLC-ES-MS and quantitatively determined using HPLCICP-MS. The use of a collision cell and H2 reaction gas allowed selective monitoring of 77Se, 78Se and 80Se masses. The reaction products were effectively separated on a C8 column with a mobile phase of 12% CH3OH–0.05% heptafluorobutyric acid and LODs below 1 mg l1 were reported. The selenotrisulfide derivatives were also determined in extracts from liver cytosol extracts from Se exposed rats. Lipsky et al.83 compared the concentrations of Se in toenails from a group of patients with recently diagnosed prostate cancer and a healthy control group. Nails were acid digested with microwave heating and Se quantitatively determined using ICP-MS with a DRC. Median concentrations of Se in toenails in the cancer and control groups were 528 ng g1 and 502 ng g1, respectively. The lack of any significant difference in nail Se concentrations between the two groups led the authors to question the protective role of Se for prostate cancer. Strambi et al.152 compared the Se status of adequatefor-gestational age (AGA) and small-for-gestational age (SGA) infants in the first months of life. Selenium status was assessed by quantitative determination of Se in erythrocytes and plasma using ETAAS. The authors observed lower plasma Se levels in breast-fed and formula-fed SGA infants compared with AGA infants. Breast-fed SGA infants had higher plasma Se levels than formula-fed SGA infants, which led the authors to caution that Se intake, unless supplemented, is likely to be inadequate in bottle-fed SGA infants. 1.7.23 Silver. Graham and O’Meara49 investigated the potential of XRF for the in vivo determination of Ag in skin. The spectrometer used an 125I excitation source, sample and detector arranged in a 901 geometry. With this arrangement, the analysis of Ag doped skin phantoms indicated an LOQ of 3–4 ppm (3–4 mg g1). The authors considered the system had sufficient sensitivity to be considered for non-invasive monitoring of Ag exposed workers, particularly to identify individuals with increased risk of exhibiting argyria. 1.7.24 Strontium. Vonderheide et al.153 investigated different instrumental systems for the determination of 90Sr in urine using ICP-MS. Quadrupole ICP-MS with a hexapole collision cell was insufficiently sensitive for the quantitative determination of 90Sr in the urine matrix. However, double-focusing SF-ICPMS operated with a cool plasma and medium mass resolution was sufficiently sensitive. Strontium was extracted from the urine matrix using a crown ether extraction resin, giving an enrichment factor of 200. An LOD of 0.4 pg l1 was reported and recovery of 90Sr from spiked urine samples was 82–86%. 1.7.25 Titanium. Titanium prostheses may often be coated with a biological glass to prevent corrosion. The glass coating isolates the metal implant from surrounding tissue until the coating is replaced by new bone after some three months of implantation. Barbotteau and colleagues48 examined the release of Ti from glass coated metallic prostheses using PIXE. They observed that after several months of implantation, Ti concentrations in tissue surrounding the implant were stabilised and restricted to the first tens of micrometres of surrounding bone. Wennerberg et al.154 examined Ti release from metallic oral implants in both in vitro and in vivo studies using SRXRF and SIMS. The researchers implanted titanium oral implants, with different degrees of surface roughness, into rabbit tibiae. They determined Ti release 12 weeks and one year after implantation and observed no significant correlation between the degree of surface roughness and ion release. 1.7.26 Uranides and actinides. Bouvier-Capley et al.155 presented a comprehensive review of the performance of ICP-MS for the quantitative determination of actinides in urine for monitoring of exposed populations, which they considered could be used as a guide for laboratories to select the most appropriate procedure for their particular investigation. Whilst in the recent past much of the work on these elements was related to exposures of Gulf war veterans, interest has now also focused on exposures in the general population. Gwiazda et al.156 used HR-ICP-MS to determine U isotope ratios in urine samples from American Gulf war veterans exposed to depleted U. The 235U mass was fully resolved with an instrument resolution of 4000. The authors studied three groups of veterans: exposed soldiers with embedded shrapnel, exposed soldiers with no embedded shrapnel and a reference group of deployed soldiers not exposed to depleted U. Urine U concentrations in soldiers with embedded shrapnel were significantly higher than in the other two groups, and 16 of the 17 soldiers monitored had detectable depleted U in their urine. In exposed soldiers with no embedded shrapnel, depleted U was determined in urine from 10 of the 28 soldiers studied. The researchers concluded that assessment of depleted U exposure must be based on U isotope ratio measurements rather than total U determinations. Durakovic and colleagues157 also determined U isotopes in 24 h urine samples collected from Gulf war veterans. The 238U : 235U ratio was determined using TIMS. The authors reported urinary U concentrations of 3.27 105 mg per 24 h for exposed veterans and 1.46 108 mg per 24 h in unexposed veterans. They used the measured urinary concentrations together with calculated dissolution half-times for ceramic depleted uranium oxide to estimate time zero lung burdens of depleted U. They estimated that the lung burden of depleted U at time zero could be accurately determined as late as nine years after initial exposure. Pappas et al.158 described a rapid method for the direct determination of 239Pu in urine using magnetic sector ICP-MS with a desolvating sample introduction system. The 239Pu was separated from U and potentially interfering polyatomic species in a 1 ml urine sample by solid phase extraction. The reported LOD was 1.4 fg ml1 in the presence of 1000 ng l1 of depleted U. The researchers considered the method to be sufficiently sensitive for emergency exposure assessment. Vanhaecke et al.159 also developed a rapid method the determination of total U concentrations in urine using sector field ICPMS. Urine samples were diluted 1 þ 9 v/v with 0.14 mol l1 HNO3 and calibration was performed with external standards rather than standard additions or ID to achieve a high sample throughput for epidemiological studies. The use of Re as an internal standard and optimised carrier gas flow minimised matrix interferences on the 238U : 187Re signal ratio. An LOD of 0.2 ng l1 was reported. The authors used the method to determine concentrations of U in non-exposed populations from Belgium and the Netherlands. A typical urinary U concentration of 3–4 ng l1 was found, though some urinary U values exceeded 10 ng l1. Finally, Al-Jundi et al.160 examined the influence of age and residential area on urinary Th and U in a non-exposed Jordanian population. Urine concentrations of 232Th and 238U were quantitatively determined using ICP-MS. The mean urinary concentration of both elements was found to be proportional to age up to 60 years and a noticeable drop in urinary levels was observed in subjects over 60 years old. 1.7.27 Zinc. Stenberg et al.161 described a detailed study of the isotopic composition of Zn in different biological matrices using multi-collector HR-ICP-MS. Sample preparation involved acid digestion followed by anion exchange chromatography. Most interferences were reduced to negligible levels using a high resolution setting and residual spectral interferences from species such as 35Cl16O2 and 40Ar14N2 were resolved instrumentally. Only the 35Cl2 interference on 70Zn could not be eliminated instrumentally and required further sample preJ. Anal. At. Spectrom., 2005, 20, 323–369 337 treatment for accurate quantitative determination of the 70Zn isotope. A number of studies examined Zn status and metabolism in different populations and different clinical conditions. In an important study, Vartsky et al.52 used XRF to determine Zn concentrations in prostate tissue samples removed during surgery. They reported a relationship between prostate tissue Zn concentrations and corresponding prostate-specific antigen levels in blood, which gave improved differential diagnosis of prostate cancer and benign prostate hyperplasia. The authors considered the combined measurement of these parameters provided a powerful tool for more accurate diagnosis of prostate disease and argued for the need to develop the capability for in vivo determination of Zn in the prostate. Rush et al.80 evaluated Zn determination in recently grown hair as a biomarker of current Zn status. The researchers examined seasonal variation in hair Zn levels in a healthy adult population from New Zealand. Hair samples were taken at monthly intervals between June and December. The samples were thoroughly washed and digested with HNO3 for quantitative determination of Zn using FAAS. No seasonal variation in Zn levels was found. Tanzer et al.162 investigated the impact of socioeconomic status on the Zn status of Turkish children and whether Zn status had any effect on anthropometric parameters. Blood samples were taken from 432 randomly selected children aged between 7 and 11 years. Each child’s height and weight were also recorded. Serum Zn concentrations were determined using AAS. Mean serum Zn concentrations in children with low and middle socioeconomic status were 56.3 and 86.6 mg dl1, respectively, whilst those in the highest socioeconomic status had a mean serum Zn concentration of 110.7 mg dl1. A height for age Z-score of 2 or lower was recorded for 56% of children with a low socioeconomic score compared with less than 10% of children with a medium or higher socioeconomic score. Cavdar et al.81 described the results of a longitudinal study of plasma and hair Zn levels in pregnant women. Plasma and hair Zn concentrations were quantitatively determined using AAS. The authors reported that both hair and plasma Zn declined significantly during the second trimester of pregnancy. They also noted a significant difference in plasma Zn levels between well-nourished and poorly-nourished study groups. Analyses of clinical and biological materials are recorded in Table 1. 2 Analysis of drugs and pharmaceuticals, traditional medicines and supplements This subject spans the clinical and food topics, particularly with yeasts and plant-based remedies, which represent an obvious link between these application areas. In addition to discussion here, there are entries within both Tables and, because of the importance of measurements in tissue specimens, in Part 1 within the sections on individual elements (e.g., for boron and platinum). Alexiu et al.163 evaluated modifiers to stabilise Hg in its determination in pharmaceuticals by ETAAS. Under optimised conditions, the two systems examined (4% H2O2-4% HCl and 10% PdCl2) gave LODs of 0.1 and 0.02 mg l1, respectively. The latter was used in the final method, which was applied to the determination of Hg in thimerosal batches and in gammaglobulinic vaccines. Satisfactory recovery of added Hg (96-102%).was demonstrated. The toxic elements, As, Cd and Hg, were determined by Kim164 in 55 calcium supplements available on the Korean market. Arsenic and Cd were determined by ETAAS with Zeeman background correction; Hg was determined with a dedicated Hg analyser. Supplements made from shark cartilage had the highest Cd and Hg concentrations (mean: 0.13 and 0.06 mg kg1, respectively), but the daily intake of these elements would still be well within the 338 J. Anal. At. Spectrom., 2005, 20, 323–369 Provisional Tolerable Daily Intake set by the FAO/WHO Joint Food Additive and Contaminants Committee. Traditional plant-based medicines all around the world are being examined for their trace element content or so it would seem from the publications in this review year. In Pakistan, Sahito et al.165 determined 15 elements in different parts of the plant Azadirachta indica by FAAS. High concentrations of the essential elements Cu, Fe and Zn were found together with disturbingly high concentrations of the non-essential element Al (48-99 mg g1). Herbal medicines in Brazil were analysed for their Cd, Hg and Pb content.166 Caldas and Machado digested samples of ten different types of herbal remedies with HNO3 and determined the elements by AAS. Most levels were low enough to not be a health concern, but the Pb concentrations found in 3 out of 15 samples of horse chestnut (Aesculus hippocastanum) were high: 153, 156 and 1480 mg g1, respectively. Consumption of this on a regular basis would provide up to 440% of the Provisional Tolerable Weekly Intake for Pb. Also from Brazil, Flores et al.6 applied their direct solid analysis technique in FAAS to the determination of Cu in medicinal plants. This technique, described in more detail in section 1.2.2, allowed more than 50 samples h1 to be measured with an LOD of 1.2 mg g1. Results agreed well with those obtained after wet digestion and conventional FAAS. In Serbia, Razic et al.167 determined nine elements in Echinacea purpurae by FAAS and FAES. The composition in root, stem, leaves and flowers differed significantly but evaluation of the data by multivariate methods revealed two distinct groups of elements showing similar patterns—one containing Cu, Fe, Li and Mn and a second consisting of Ca, Mg, Ni and Zn. A method using ETAAS for the determination of Cd in the Chinese medicine, Dioscorea zingiberensis, was developed by Chen.168 Palladium was chosen as the chemical modifier. Arsenic and Hg in seven Chinese medicinal herbs were determined by Long et al.169 with HGAFS and CVAFS, respectively, after microwave-assisted pressure digestion. The LODs were 0.1 and 0.03 mg l1 for As and Hg, respectively. Results agreed well with those obtained by ICP-AES. Yang et al.,170 also using HGAFS, were able to speciate AsIII and AsV in a leachate of Chinese medicines by using prior ion exchange separation. Simultaneous determination and speciation of As and Sb in extracts of Chinese medicinal herbs was possible in the method developed by Sun et al.171 They used HG with a dual-channel AF spectrometer to measure AsIII, SbIII, total As and total Sb. In a comparison of different extraction systems, Soxhlet extraction was the preferred technique. Much of the published work referring to yeast, garlic and medicinal plants is concerned with the procedural detail of speciation, mainly for Se, with some interest in As. Two groups examined speciation and bioavailability of Se from yeast-based supplements and intervention agents used in cancer prevention studies. In the study by Dumont et al.172 yeast supplements were subjected to in vitro simulated gastrointestinal digestion. Selenium species in the digests were separated by HPLC for quantitative determination using ICP-MS and characterisation using ES-MS-MS. Chromatographic conditions were chosen to be compatible with both mass spectrometric techniques. The main Se species extracted by both gastric and intestinal digestion was SeMet. Two minor Se species Se-Cys and Se-(O)methionine were also identified. Larsen et al.173 extracted Se species from yeast based intervention agents using proteolytic digestion and quantitatively determined the released species using ion-exchange HPLC coupled with ICP-MS. Selenomethionine was again the predominant species released in the digest, together with three other unidentified species. The authors noted marked differences in the relative amounts of the Se species in batches of tablets from the same manufacturer and between tablets from different producers. In more recently produced tablets, SeMet represented some 54–60% of total Se compared with only 27% in the tablets used for the national Table 1 Clinical and biological materials Element Matrix Technique; atomisation; presentation Actinides Urine MS;ICP;L Ag Skin XRF;-;- Al Brain (rat) AMS;-;S Al Neuroblastoma cells MS;ICP;SEC MS;ICP;CE Al Blood, serum, urine AMS;-;- Al AA;-;L Al Amino acids (human blood) Serum, glomerular filtrate (rat) Al Kidney (rat) SIMS;-;- As Tissue (mouse) PIXE;-;- As Chinese herbal medicines AF;-;- As Urine MS;ICP;IC As Urine (rat) MS;ICP;LC As Hair (human), clam AA;ETA;L As Chinese herbal medicines AF;HG;L As Skin (rat) AA;ETA;- As Algae, blood, packed blood cells, serum, urine and simulated gastric fluid Traditional Chinese medicines MS;ICP; L AF;HG;MS;ICP; HPLC MS/ MS;ES;HPLC As AA;ETA;L AF;HG;LC Sample treatment/comments Ref. The performance of ICP-MS for the determination of actinides in urine was investigated and compared with other available techniques The capability for measuring Ag concentrations in skin was investigated using an 125I source to excite the Ag K X-rays and a 901 geometry. The lowest detectable concentration was 3–4 ppm after 10–20 min measurement periods 26 Al from maternal milk reached the brain of suckling rats and a considerable fraction (12–20%) remained in the brain tissue throughout their lifetime (ca. 2 y) The main Al species in neuroblastoma cells exposed to Al lactate were Al–transferrin complex in control cells and a low Mr Al-complex in neuroblastoma cells Al toxicokinetics in patients with chronic renal failure and controls were investigated using 26Al (given as a single oral or i.v. dose) as tracer and AMS for the detection of the tracer in blood, urine and serum fractions The binding of Al to amino acids present in human blood was investigated in vitro by combining IC, ultrafiltration and AAS In an experimental study of renal handling of Al in rats infused with Al citrate, Al concentrations in serum and glomerular filtrate indicated greater Al filtration than predicted from an in vitro model and minimal (19–26%) reabsorption The high sensitivity of SIMS was exploited to obtain images of the distribution of Al and In in rat kidney and to confirm the mechanism of elimination of low doses of Al and In, after their accumulation in the lysosomes of the proximal tubule cells In an investigation of As2O3 for the treatment of solid tumours in a murine xenograft model, As was preferentially accumulated in tumour rather than other tissues AsIII was measured in a Chinese herbal medicine (Niuhuang Jiedu tablets), using 3.6–5.8 mol l1 HCl and 2.0–2.5% NaBH4, followed by reduction of AsV to AsIII and determination of total As. The concentration of AsV was calculated by difference. RSD was 0.8–2.9%. Analytical recovery was 96.7–116.3% and 109.0–116.8% for AsIII and AsV, respectively Total As, AsIII, AsV and DMA were determined simultaneously by isocratic elution using anionic IC coupled with ICP-MS. LODs were 0.31 ng ml1 (AsIII), 0.45 ng ml1 (Asv), and 2.09 ng ml1 (DMA) DMAIII, MMAIII and TMA, extracted in CCl4 as the diethylammonium DDC complexes, were determined by LC-ICP-MS without significant changes in their concentration during storage or pre-treatment Ir, Pd and Rh were evaluated as permanent chemical modifiers for the determination of As in digested biological samples by tungsten coil ETAAS. The highest sensitivity was obtained with Rh (2.0 mg). LOD was 29 pg, RSD 4.4% and analytical recovery 94 8%. Sample throughput was 21 h1 A method was developed for the simultaneous determination of total As, AsIII, total Sb and SbIII by HG-double channel AFS. Samples (1 g) were extracted with 9 þ 1 CH3OH–H2O in a Soxhlet extractor and the aqueous fractions diluted with HCl or acetate buffer for the determination of the total content or the trivalent species, respectively. LODs were 9.4 ng g1 (AsIII), 5.6 ng g1 (total As), 6.3 ng g1 (SbIII) and 1.9 ng g1 (total Sb). Analytical recovery of added As and Sb was 495 and 492%, respectively Following intradermal injections of NaAs2O3 in rats, increased vascular permeability was observed. After an initial increase, tissue As declined rapidly and returned to baseline levels within 1 h The human metabolism of arsenosugars from the Chinese seaweed Laminaria was investigated in experimental studies, using NAA, ICP-MS and HGAFS to determine total As in algae and human samples, and HPLC-ICP-MS and HPLC- ES-MS/MS to investigate As species 155 The determination of both AsIII and AsV in traditional Chinese medicines was achieved using ion exchange chromatography and HGAFS. LOD was 89 ng ml1 and recovery ranged from 91 to 109% 49 84 86 42 278 85 39 97 206 279 92 94 171 280 281 170 J. Anal. At. Spectrom., 2005, 20, 323–369 339 Table 1 340 (continued ) Element Matrix Technique; atomisation; presentation As Skeleton fossils (dinosaur) AF;HG;AE;ICP;L As Chinese medicinal herbs AF;HG;L AF;CV; L AE;ICP;L As Hair SIMS;-;- As Urine MS;ICP;HPLC As Skin XRF;-;- As Urine AA;HG;HPLC As Blood, urine AA;ETA;L AA;HG;L As MS;ICP;HPLC As Environmental and biological samples Urine, wool extract As Urine MS;ICP;HPLC As Fingernail, hair, urine MS;ICP;HPLC As Urine (CRMs, RMs) MS;ICP;HPLC As Dietary calcium supplements AA;ETA;L AA;CV;L Au Serum (dog) AA;-;L B Soft tissue SIMS;-;AE;ICP;- B Serum, urine AA;ETA;L B Blood plasma, urine MS;ICP;L MS;ICP;HPLC MS;ES;HPLC MS;ES;L J. Anal. At. Spectrom., 2005, 20, 323–369 Sample treatment/comments Ref. Samples of skeleton fossils of dinosaurs unearthed in China were digested with aqua regia at 100 1C, prior to As determination by HGAFS and ICP-AES (for comparison). LOD was 0.03 mg l1 and recovery ranged from 97 to 109%. Higher As concentrations were found in the skeleton fossils suggesting that As toxicosis contributed to their extinction As was determined by HGAFS and Hg by CVAFS in Chinese medicinal herbs after closed-vessel microwave digestion. Analytical conditions were optimised using an orthogonal design. ICP-AES was used for comparison (As). LODs were 0.1 ng ml1 (As) and 0.03 ng ml1 (Hg) Using nano-SIMS 50, ion imaging was performed on microtomed hair cross-sections to determine As concentration and distribution. The linearity of the relationship between the SIMS signal and As concentration was demonstrated As species were determined in urine by HPLC-ICP-MS with a hexapole collision cell and an ion-exchange column. The mobile phase was 0.1 mmol l1 EDTA–10 mmol l1 NH4NO3–0.05% HNO3. AsV, MMA, DMA, AsIII and AB were separated within 14 min, but AC, TMAO and TMI eluted together at about 40 min The preliminary results of the development of an XRF system to measure skin As in vivo were reported. LODs were 3.5 0.2 and 10.3 0.5 ppm in 90 and 1801 measurement geometries, respectively, for a measurement time of 30 min A method for the simultaneous quantification of AsIII, AsV, MMA, DMA and TMAO in human urine by HPLC-HGAAS via a FI interface was presented. LODs ranged from 1.1 (TMAO) to 2.6 mg l1 (AsV) Methods for blood and urine mineralisation in the presence of different As species, prior to the determination of As by HGAAS or ETAAS, were investigated A review of As toxicity and currently used sample treatment and detection procedures for As quantification and speciation was presented Dimethylarsinothioic acid was identified (by HPLC, coupled simultaneously to ICP-MS and ES-MS, quadrupole TOF-ES-MS and 1 H NMR) as the main product of the in vitro reduction of methylated AsV species with Na2S2O5/Na2S2O3 and was also found in urine and wool extract from sheep feeding on seaweed AB and DMAV were the major As species excreted (together with other unknown metabolites) in urine from 9 volunteers who ate a meal of blue mussels. Individual difference in the excretion patterns were observed As species in samples (urine, H2O–CH3OH extract of freeze-dried red blood cells, TCA treated plasma, and water extract of hair and fingernails) from Bangladesh people and controls were investigated as biomarkers of As exposure As species were determined in two CRMs (NIES 18 and NIST SRM2670a) and three other RMs, diluted 1 þ 3 prior to analysis by gradient elution anion or cation exchange HPLC-ICP-MS. Of several As species, 9 were identified. As species concentrations added up to the target values for total As Mean concentrations of As, Cd and Hg in calcium supplements, as determined by Zeeman-effect ETAAS after microwave-aided digestion (As, Cd) and by an Hg analyser, were 0.48, 0.02 and 0.01 mg kg1, respectively The preclinical tolerance and pharmacokinetics of a novel chemotherapeutic agent, tetrakis(trishydroxymethyl)phosphine AuI Cl, were assessed in dogs Dynamic SIMS was used to obtain images showing the distribution of 10B in biological tissues, as part of research into B NCT. Results obtained on tissue standards, as B : C signal ratios, correlated to B measurements by ICP-AES B concentrations were significantly lower in serum and urine of menopausal women compared with controls B was determined in blood plasma and urine by ICP-MS, using ID and a high efficiency DIN. Protein precipitation with HNO3 removed 98 169 95 91 50 282 93 87 89 90 75 283 164 109 41 100 99 Table 1 Element (continued ) Matrix Technique; atomisation; presentation Sample treatment/comments Ref. 1 Bi Urine AA;ETA;FI Ca Serum MS;ICP;L Ca Diet, faeces, urine and sweat AA;-;- Cd Cd Urine Natural waters, urine AA;ETA;FI AA;ETA;FI Cd Chinese herbal medicine AA;ETA;- Cd Urine AA;ETA;L Cd Blood AA;ETA;L Cd Biological and environmental samples AA;-;L Cd Medicinal herbs AA;-;- Cd Biological and environmental samples AA;ETA;- Cd Urine AA;ETA;L Cd Hair, nail AA;F;AA;ETA;- Cd Biological CRMs AA;ETA;L Cd Dietary calcium supplements Serum AA;ETA;L AA;CV;L AA;ETA;L Co 94% of C. LOD was 0.6 ng ml and RSD o2.0% for blood plasma and o1.3% for urine samples On-line preconcentration with a laboratory-made FI system coupled to multi-element ETAAS was applied to the simultaneous detection of Bi, Cd and Pb in urine. LODs were 0.013 (Bi), 0.002 (Cd), and 0.0045 (Pb) mg l1. Analysis of RMs yielded results within 90–110% of the target values Proteins in serum samples (20 ml) were precipitated with diluted HNO3 and the 42Ca : 43Ca ratio in the supernatant measured by magnetic sector ICP-MS with a precision o0.5%. Results compared well with oxalate precipitation, requiring at least 0.5 ml serum Mineral (Ca, Mg, P) balance studies were carried out on Japanese volunteers over a 14 y period. The Ca, Mg and P content of diet, faeces, urine and sweat were measured by AAS (Ca, Mg) and UV spectrophotometry (P) See Bi, ref. 11 A new phase separator improved the separation of organic extracts from large volumes of aqueous phase. With NH4 diethyldithiophosphate in IBMK, the enrichment factor for Cd was 24.6, LOD 2.8 ng l1 and RSD at 0.2 mg l1 Cd 3.2% Pd was chosen as the chemical modifier for the determination of Cd in Dioscorea zingiberensis, a Chinese herbal medicine. LOD was 0.075 ng ml1 and RSD 3.8%. Analytical recoveries were between 90–110% Cd and Pb were determined by means of simultaneous ETAAS with end-capped THGA in urine samples diluted 1 þ 4 with 0.125% (m/v) Triton X-100–2.5% (v/v) HNO3–0.31% (m/v) NH4H2PO4. LODs were 0.03 mg l1 (0.36 pg) for Cd and 0.57 mg l1 (6.8 pg) for Pb. Increased sensitivity (14% and 25% for Cd and Pb, respectively) was observed in comparison with standard tubes Blood samples were diluted 1 þ 9 with 0.11% (m/v) Triton X-100 – 1.1% (v/v) HNO3 prior to Cd and Pb simultaneous determination by Zeeman-effect ETAAS. W (250 mg)–Rh (200 mg) was used as permanent chemical modifier. Charring and atomisation temperatures were 400 1C and 1500 1C, respectively, and total analysis time was 63 s. LODs were 0.03 mg l1 (Cd) and 0.8 mg l1 (Pb) and analytical recovery 101% (Cd) and 98–100% (Pb) Cd21, Cu21 and Pb21 in environmental and biological samples were separated and preconcentrated by solid phase extraction on C18 membrane disks modified with bis-2-thiophenal propandiamine, prior to analysis by AAS. LODs were 0.01 (Cd), 0.02 (Cu) and 0.25 (Pb) ng ml1 The content of Cd, Hg and Pb in herbal medicines used in Brazil was determined by AAS after HNO3 digestion. LODs were 0.20, 0.01 and 2.0 mg kg1, for Cd, Hg and Pb, respectively. Only Pb intake from horse chestnut taken on a long-term basis may be of health concern The efficiency of HNO3, Ni, Pd and Th as chemical modifiers for the determination of Cd by ETAAS, using platform and fast temperature programs, was compared. Ni (with HNO3) gave the highest sensitivity. LOD was 0.03 ng ml1 and m0 0.35 pg Cd was determined in 10 ml urine after 1 þ 1 dilution with 4.0% HNO3. Analytical conditions were optimised using a fractional factorial design. LOD was 0.12 mg l1 and m0 1.78 pg Hair and nail Cd concentrations were significantly correlated in both exposed and non-exposed subjects, but only nail levels were significantly higher in exposed subjects. Hair and nail Pb levels were significantly correlated only in exposed subjects, but both were higher than in controls A novel digestion procedure for organic materials was reported. Samples (50–250 mg) were wrapped in paper and placed in a microwave oven for 20 s at 1400 W after addition of NH4NO3 and O2. After combustion and a reflux step with concentrated HNO3 the residual C concentration was o0.4% See As, ref. 164 Serum Co levels after metal-on-metal total hip arthroplasty were only slightly increased compared to controls and remained stable over a 5 y period 11 102 284 11 13 168 63 62 7 166 285 101 77 3 164 104 J. Anal. At. Spectrom., 2005, 20, 323–369 341 Table 1 342 (continued ) Technique; atomisation; presentation Element Matrix Co Vitamin B12 tablets AA;F;L AA;ETA;L Co Oral mucosa cells MS;ICP;- Co Skin, sweat (synthetic) AA;ETA;L Co Hair AA;F;L Cr Saline solutions AE;ICP;L Cr Natural waters, urine AA;ETA;L Cu Serum, nails AA;-;- Cu Liver tissue MS;ICP;LA Cu Serum AA;-;L Cu Serum AE;ICP;L Cu Plasma, human milk AA;-;L Cu Liver PIXE;-;- Cu Serum AA;-;L Cu AA;-;L Cu Biological and environmental samples Nails, serum AA;-;- Cu Brain (rat) AA;-;L Cu Erythrocytes AA;-;- Cu Erythrocytes, serum XRF;-;- Cu Serum (dromedary) AA;F;L J. Anal. At. Spectrom., 2005, 20, 323–369 Sample treatment/comments Ref. The preconcentration of Co complexes with pyridylazo compounds (PAN, PAR, 5-Br-PADAP) was achieved using Triton X-100 and SDS, as a novel mixed micellar system, and inducing phase separation by HCl or NaCl addition. LOD was 1.6 mg l1, linear range 25–200 mg l1 and extraction recovery 98–102%. The results were compared with ETAAS Co and Ni levels in oral mucosa cells were about 3-fold higher in orthodontic patients than controls and significantly and positively correlated with the results of cell viability and comet assays Measurements of Co by ETAAS and Co21 by differential-pulse polarography in human skin, donor and/or receiving phases, as parts of an in vitro system, demonstrated for the first time how Co can permeate through the skin A solid phase extraction and 200-fold preconcentration procedure for the determination of Co and Ni in hair was developed. Their ethyl xanthate complexes, quantitatively retained on benzophenone in the pH range of 8.0–10.0, were dissolved in 5 ml of DMF and analysed by FAAS The release of metals from stainless steel and Ni–Ti orthodontic alloys, kept in a 0.9% NaCl solution for 1 month, was measured by ICP-AES. No effect was observed on the survival and DNA synthesis of human fibroblasts exposed to the immersion media The preconcentration and separation of Cr species in natural waters and urine was obtained by an automated combination of chelation or anion exchange chromatography and ETAAS. LODs for CrIII and CrVI were 0.14 and 0.08 ng ml1, respectively In patients with migraine, serum Cu and Mn levels were higher and Zn lower than in controls, but, in nails, only Mn levels were significantly higher in patients The precision of a method for two-dimensional mapping of Cu and Zn in liver sections, based on LA-ICP-TOF-MS, was assessed on a pig liver CRM, using C as an internal standard, and ranged from 1.6 to 6.1% Patients with dilated cardiomyopathies had higher Cu and lower Zn concentrations in serum than controls. Mg levels did not differ significantly A method for the simultaneous determination of Cu and Fe in serum by UV detection of their complexes with 2-(5-bromo-2-pyridylazo)-5(N-propyl-N- sulfopropylamino)aniline was compared with ICP-AES. LODs were 0.4 mg l1 (Cu) and 0.2 g l1 (Fe) and RSD was o1% In a study of 191 mothers, Cu, Fe and Zn levels in milk were not dependent on maternal trace element status, as assessed from plasma Cu and Zn concentrations and indices of Fe status (haemoglobin, plasma ferritin, soluble transferrin receptors and zinc protoporphyrin) The liver content of Cu, Fe and Zn in patients with chronic liver disease caused by hepatitis C virus was measured in thin-needle biopsy specimens. Cu levels were higher in patients with hepatocellular carcinoma Maternal and cord blood serum levels of Cu, Fe and Zn in a sample of Jordanian women and their newborns were reported See Cd, ref. 7 10 Cu, Mn and Zn concentrations were determined in nails and serum from patients with epilepsy and controls. Cu in serum and Mn in nails were significantly higher in patients than controls Cu, Fe and Zn levels in rat cerebral cortex were measured after wet ashing to investigate alterations of physiological conditions due to subacute or subchronic exposure to formaldehyde In patients, who had undergone high-dose chemotherapy and autologous stem cell transplantation, erythrocyte Fe and Zn, but not Cu, levels, increased together with oxidative stress markers In patients with hyperthyroidism, serum, but not erythrocyte, Cu and Zn levels changed significantly after therapy with 131I and were positively correlated with triiodothyronine and thyroxine Cu supplementation had no effect in dromedaries with normal Cu serum levels, but serum Cu increased to normal values in Cu deficient animals 105 103 9 132 12 286 37 107 287 108 54 65 7 288 289 290 60 291 Table 1 (continued ) Element Matrix Technique; atomisation; presentation Cu Cu Plasma Human arteries AA;-;L MS;ICP;- Cu MS;ICP;SEC Cu Metallothionein fractions (rat liver and kidney) Serum, ultrafiltrate AA;ETA;L Cu Medicinal plants AA;F;S Cu Cu Biological CRMs Human milk and infant formulas AA;ETA;L AA;ETA;L Cu Plasma AA;-; L MS;ICP;L Cu Serum AA;F; L AA;ETA;L Fe Cancer tissue XRF;-;- Fe Fe Fe Fe Fe Serum Brain (substantia nigra) Plasma, human milk Liver Serum, transferrin AE;ICP;L XRF;-;XANES;-;AA;-;L PIXE;-;MS;ICP; HPLC Fe Fe Fe Fe Serum Brain (rat) Erythrocytes Food, human faeces AA;-;L AA;-;L AA;-;MS;ICP;- Fe Fe Erythrocytes, serum Erythrocytes XRF;-;MS;ICP;L Fe Human arteries Gd Human glioblastoma cells Hair MS;ICP;EPR;-;SIMS;-;- Hg AF;CV;GC Hg Brain, kidneys, liver (mouse) AA;CV;- Hg Hg Medicinal herbs Scalp hair, urine AA;-;AA;-;- Sample treatment/comments Ref. Zn supplementation in infants did not influence Cu status The quantification of Cu and Fe by EPR spectroscopy and ICP-MS provided evidence for increased levels of Cu and Fe in carotid lesions in comparison with healthy human arteries The binding of metals (Cu and Hg) in tissues of rats fed cinnabar and controls was investigated 292 30 Solid phase extraction and ultrafiltration were compared for the separation of free and protein-bound serum Cu 0.05–1.5 mg of ground sample (o80 mm) were introduced directly into the flame as a dry aerosol using a T-quartz cell set between the burner and the optical path. Characteristic mass was 0.8 ng Cu and absolute LOD 1.2 ng. The results were compared with those obtained after sample digestion See Cd, ref. 3 The influence of gastric pH in the first stage of enzymolysis on the bioavailability of Cu from human milk and infant formulas was evaluated in vitro A method was reported for the selective extraction of exchangeable Cu from blood plasma, based on dialysis in the presence of histidine and subsequent Cu pre-concentration with Chelex-100 Albanian immigrant mothers and their neonates (n ¼ 820) had significantly lower serum Cu and Se levels than Greek mothers and their children (n ¼ 1118), as a consequence of lower animal protein, Cu and Se intakes In a prospective randomised trial, Fe concentrations in intestinal cancer tissue and in colon and rectum polyps were investigated by TRXRF See Cu, ref. 287 XRF and XANES were applied to investigate the distribution and chemical state of Fe in brain tissue See Cu, ref. 108 See Cu, ref. 54 In a study of the binding patterns of V to serum transferrin by anion-exchange HPLC-HR-ICP-MS, 56Fe, 32S and 51V could be monitored simultaneously at a resolution of 4000 in samples of 1 ml serum or 2 mg transferrin See Cu, ref. 65 See Cu, ref. 289 See Cu, ref. 290 Fe isotope ratios were determined in food and human faeces by double focusing ICP-MS, using a resolution of 3000 to overcome interferences (40Ar16O, 40Ar14N) See Cu, ref. 60 Isotope ratios (56Fe : 54Fe and 57Fe : 54Fe) were measured in erythrocytes by MC-ICP-MS. Interferences were reduced using a desolvating nebuliser and separation of Fe from the matrix by IC See Cu, ref. 30 106 In support of NCT, SIMS was applied to map the subcellular distribution of 157Gd and the other 6 naturally occurring Gd isotopes, in human glioblastoma cells Methylmercury was determined in hair by GC-CV-AFS, after headspace solid phase microextraction. Both the GC-CV-AFS interface set-up and the digestion parameters (acid type, concentration, temperature and time) were optimised, to avoid methylmercury degradation. The stability of the digested samples was evaluated The determination of Hg content in tissues of albino and pigmented mice treated with Hg-containing skin-lightening creams showed that Hg was readily absorbed through the skin, but melanin had a protective role See Cd, ref. 166 A standardised procedure evaluating Hg burden was developed based on measurements of Hg in scalp hair and urine samples from 2223 subjects (before and after administration of DMPS) and Hg release from dental amalgams by a newly developed, amalgam specific chew test 293 6 3 294 295 296 113 287 45 108 54 297 65 289 290 111 60 110 30 40 128 298 166 126 J. Anal. At. Spectrom., 2005, 20, 323–369 343 Table 1 Element Matrix Hg Metallothionein fractions (rat liver and kidney) Chinese medicinal herbs Hg Technique; atomisation; presentation Sample treatment/comments Ref. MS;ICP;SEC See Cu, ref. 293 293 See As, ref. 169 169 The use of PdCl2 (10%) as the chemical modifier gave a better LOD (0.02 mg ml1) than 4% HCl–4% H2O2 (0.1 mg ml1). Ashing and atomisation steps were carried out at 250 1C and 1800 1C, respectively. Recovery was 96–102% Hg was measured, by CVAAS and CVAFS, respectively, in blood and hair samples from pregnant women and their newborns. Hg levels in cord blood were significantly higher than in maternal blood and influenced by fish consumption before and during pregnancy An on-line pre-concentration procedure, based on solid phase extraction with automatic sequential dispensing, was devised. With the aid of a laboratory-made device, connected directly to the ICP-AES torch, the APDC–Hg complex was retained on PTFE turnings, SnCl2 added, and Hg purged into the plasma using an Ar flow. The method was linear over the range 0.02–5.0 mg l1, LOD was 0.01 mg l1 and RSD 3.1% at 1.0 mg l1. Under the stated conditions, sample throughput was 30 h 1 Hg was determined by FI-CVAAS in 300 ml blood, diluted 1 þ 1 v/v with 10% v/v TMAH, incubated for 1 h at room temperature and further diluted 1 þ 4 v/v with 2% v/v HCl. LOD was 0.2 mg l1 and bias 2.5%. Precision (o10%) was better than with on-line microwaveassisted digestion The evidence of exposure to Hg and Pb and the mechanisms of acquisition and storage of these metals at early stages of human development were reviewed The release of Hg0 from in situ fillings and in vitro amalgam specimens was investigated using Zeeman-effect ETAAS coupled with an electronic controlled apparatus allowing aspiration of (oral) air under a standard protocol. RSD for repeated sampling from a single patient ranged from 18 to 25%. The increase in Hg0 levels after insertion of new fillings was detectable even in the presence of old ones See As, ref. 164 163 Hg Pharmaceuticals AF;HG;L AF;CV;L AE;ICP;L AA;ETA;- Hg Blood (maternal and cord), hair AA;CV;L AF;CV;- Hg Seafood (CRM), blood, hair and urine AE;ICP;CV Hg Blood AA;CV;FI Hg Human and cow milk -;-;- Hg Oral air AA;ETA;L Hg Dietary calcium supplements Kidney (rat) Erythrocytes, blood plasma AA;ETA;L AA;CV;L SIMS;-;AA;-;- Mg Mg Serum Serum, hair and lenses AA;-;L AA;-;- Mg Faeces, erythrocytes, urine TIMS;-;MS;ICP;L Mg Diet, faeces, urine and sweat Serum, nails Blood, brain, lung, liver (rat) Nails, serum Human milk AA;-;- In Li Mn Mn Mn Mn 344 (continued ) AA;-;AA;-;AA;-;AE;ICP;L MS;ICP;HPLC Mn Vitamin-mineral tablets AA;ETA;S Mo Blood plasma MS;ICP;L Ni Oral mucosa cells MS;ICP;- J. Anal. At. Spectrom., 2005, 20, 323–369 79 21 88 117 125 164 See Al, ref. 39 In a retrospective study of 165 patients treated with Li salts, the concentrations of Li1 in erythrocytes and plasma and their ratio were evaluated as indices of toxicity See Cu, ref. 107 Mg and Zn were measured in serum, hair, and lens from diabetic and nondiabetic patients, who underwent surgery for senile cataracts. Only lens Zn levels were significantly higher in diabetic than in nondiabetic patients Mg absorption was determined from the concentration of the tracer 25 Mg in 24 h urine pools or erythrocytes collected 14 days after challenge as an alternative to faecal collections See Ca, ref. 284 39 121 See Cu, ref. 286 Mn content was increased in tissue but not in blood of rats exposed to stainless steel welding fumes See Cu, ref. 288 Mn species in subfractions of human milk obtained by centrifugation were investigated by ICP-AES and SEC-ICP-MS. The defatted fraction contained approx. 2.9 mg l1 Mn, most of which was in the low Mr fraction. Both Mn21 and Mn citrate complex were identified in the respective SEC fractions by strong anion exchange ICP-MS Finely-ground samples were introduced directly into the furnace by means of a solid autosampler system. Calibration with aqueous standards, standard additions or solid certified standards was investigated. The results were compared with those obtained after acid digestion Plasma Mo levels, determined by ID-ICP-MS in an experimental human study, reflected dietary Mo intake See Co, ref. 105 286 124 107 299 122 284 288 123 214 130 105 Table 1 (continued ) Element Matrix Technique; atomisation; presentation Ni Ni Ni Saline solutions Hair Tissue extracts AE;ICP;L AA;F;L MS;ICP;HPLC P Biological samples MS;ICP;L P AA;-;- Pb Diet, faeces, urine and sweat Blood AA;-;- Pb Pb Urine Tooth enamel AA;ETA;FI MS;ICP;LA Pb Pb Pb Urine Blood Blood AA;ETA;L AA;ETA;L AA;ETA;L Pb AA;-;L Pb Biological and environmental samples Blood, milk (cow) AA;-;L Pb Pb Medicinal herbs Teeth AA;-;AA;ETA;- Pb Hair AA;F;HG Pb Hair, nail Pb Blood AA;F;AA;ETA;AA;ETA;L Pb Blood, bone, human milk Pb Bone AA;ETA;L XRF;-;MS;ICP;L XRF;-;- Pb Blood AA;ETA;L Pb Dialysis concentrates AA;HG;FI AA;ETA;L Pb Human and cow milk Bone, blood -;-;- Pb XRF;-;AA;ETA;L Sample treatment/comments Ref. See Cr, ref. 132 See Co, ref. 9 Seven Ni species were separated from tissue extracts by a novel procedure based on the coupling of sequentially applied anion-exchange and SEC with SF ICP-MS P and S were detected as PO1 and SO1 by DRC-ICP-MS, using O2 as the reaction gas. The method was applied to the detection of phosphoproteins in HCl digests. The P : S ratio allowed differentiation of malignant cell lines from primary cultures and cancerous from normal tissue in needle biopsies (0.2–0.5 mg) from 4 patients. Phosphoproteins were detected from polyacrylamide gels using LA-ICP-MS with a LOD of 0.6 mg g1, but S detection was hampered by the high S content of blank gels See Ca, ref. 284 132 9 131 In a paediatric population blood Pb levels were significantly reduced over the period 1991–2001. Blood zinc protoporphyrin increased sharply only at blood Pb concentrations above 18 mg dl1 See Bi, ref. 11 LA was compared with sample digestion for the determination of the Pb : Ca ratio in the enamel of deciduous incisors (a biomarker of in utero Pb exposure) by ICP-MS. LOD for Pb was 11 mg kg1 and the RSD for the Pb : Ca ratio was 3.4% See Cd, ref. 63 See Cd, ref. 62 Pb was determined in blood by ETAAS using Pt as chemical modifier. Tantalum foil lining extended the tube life. LOD was 1.74 mg l1, RSD o5% and analytical recovery 96%–103% See Cd, ref. 7 119 The circadian variations of Pb in blood and milk of dairy cows after intravenous administration of CH3COOPb in winter were investigated See Cd, ref. 166 Pb was determined by ETAAS in the superficial enamel of deciduous teeth from pre-school children (Brazil). The sampling technique involved application of 5 ml of 1.6 mol l1HCl in 70% (v/v) glycerol to a delimited tooth area (1.6 mm diameter). Biopsies deeper than 3.9 mm gave more reliable results Nebulisation assisted by HG with K3Fe(CN)6–HCl improved the sensitivity (13.4 fold) of Pb determination in hair. LOD was 2.8 mg l1 and the analytical recovery range 96–99% See Cd, ref. 77 Pb concentration was significantly higher in earlobe than in corresponding venous blood samples from 126 occupationally exposed subjects The relationships between Pb in blood and bone (as indices of previous or current exposure) and Pb in human milk were investigated in a sample of lactating Mexican women Because body Fe burden is inversely associated with Pb absorption, the association of the C282Y and/or H63D haemochromatosis gene with body Pb burden was investigated among elderly men in the Normative Aging Study The estimate of uncertainty from performance data was demonstrated using the determination of Pb in blood by Zeeman-effect ETAAS as an example and comparing different approaches to the estimate of trueness Pb levels ranging from 10 to 70 ng ml1 were determined in dialysis concentrates by FI-HG-AAS. LOD was 0.7 ng ml1 for a 500 ml injection volume. RSD was 3.7% at 20 ng ml1. Results were compared with those obtained on the same samples by ETAAS after removal of the matrix by solid phase extraction with Chelex 100 See Hg, ref. 117 In a study of bone and blood Pb levels in minorities living in the Boston (USA) area, statistical analysis of data suggested higher bone Pb levels in subjects 455 y, even when compared to white subjects of similar profiles 133 284 11 38 63 62 300 7 232 166 120 78 77 115 118 116 114 301 117 302 J. Anal. At. Spectrom., 2005, 20, 323–369 345 Table 1 Element Matrix Technique; atomisation; presentation Pb Blood AA;ETA;L Pb Blood, bone XRF;-;AA;ETA;L Pd Animal tissue (mussels) AA;ETA;L XRF;-;- Pd Polymers, pharmaceuticals, auto catalyst RM AA;ETA;S Pd AE;ICP;ETV Pd Biological and environmental samples Urine MS;ICP;L Pt Water, urine MS;ICP;HPLC Pt Liver (rat) AA;-;- Pt Pt Animal tissue (mussels) Breast cancer cells AA;ETA;L XRF;-;MS;ICP;- Pt Reaction buffer AA;-;- Pt Biological and environmental samples Urine, airborne particulate matter AE;ICP;ETV Pt Pt Urine Plasma, ultrafiltrate, and urine MS;ICP;L MS;ICP;L Pt Urine MS;ICP;L Pt Ultrafiltrates AA;-;L Pu Urine MS;ICP;L Rh Animal tissue (mussels) AA;ETA;L XRF;-;- Pt 346 (continued ) MS;ICP;L J. Anal. At. Spectrom., 2005, 20, 323–369 Sample treatment/comments Ref. In a longitudinal study (Instanbul) of infants up to 2 y old, blood Pb levels increased with age. Consumption of herbal tea and living with smokers in centrally heated homes were identified as risk factors for higher blood Pb levels as well as fathers’ occupations as manual workers In a prospective study, changes in renal function in relation to baseline Pb levels in blood, patella and tibia (mean values: 6.5 mg dl1, 32.4 mg g1, and 21.5 mg g1, respectively), diabetes, and hypertension were assessed among middle-age and elderly men. Results suggested that decline of renal function depended on both bone and blood Pb levels, with a more pronounced effect in diabetic and hypertensive subjects A method for the routine determination of Pd, Pt and Rh in animal tissues, based on microwave-aided digestion and ETAAS was evaluated and compared with adsorptive CSV (Pt and Rh) and TXRF (Pd). LODs were 90 ng g1 (Pd), 270 ng g1 (Pt) and 13 ng g1 (Rh), RSDs o10% and analytical recoveries 495% A novel approach, based on solid sampling, was proposed for the direct determination of Pd in various matrices. The procedure allowed calibration with aqueous standards and reduced risk of analyte losses and contamination. LOD was 0.4 ng g1 and RSD ranged from 3 to 15% A novel method was described for the determination of Pd, Pt and Rh, based on the introduction of their DDC complexes into the plasma by ETV at 1100 1C. LODs were 1.4 (Pd), 5.4 (Pt) and 0.8 (Rh) ng ml1 The concentrations of Pd, Pt and Rh in urine samples from residents in either a rural or an urban area were determined by SF-ICP-MS after 1 : 4 (v/v) dilution of the samples HPLC-ICP-MS, with on-line ID, was applied to the speciation of cisplatin and its degradation products in aqueous solutions of Cl and in human urine. LODs were 0.74, 0.69 and 0.65 mg l1 for cisplatin, monoaqua- and diaquacisplatin, respectively The delivery rate and tissue distribution of carboplatin, an anticancer agent, released from implants into rat livers after radiofrequency ablation, were investigated See Pd, ref. 139 303 A systematic study of intracellular Pt uptake and accumulation ratio in breast cancer MCF-7 cell line was performed, using sub-acute concentrations of various PtII complexes. ICP-MS was chosen for Pt quantification at low concentrations The binding of Pt drugs (oxaliplatin, carboplatin, and cisplatin) to glutathione was monitored by UV-absorption spectroscopy, HPLC and AAS See Pd, ref. 138 Pt was determined in urine samples from 100 adults from Budapest and Vienna by ICP-MS after 10-fold dilution with bidistilled water. Airborne particulate matter samples, collected in the same cities, were also analysed See Pd, ref. 135 The determination of Pt in plasma, ultrafiltrate and urine of patients treated with antitumour agents was reported. LOQs were 1.0, 0.1, and 2.0 mg l1 in the 3 matrices Pt levels in urine, measured by SF-ICP-MS, did not differ between policemen involved in controlling traffic and those working only in offices In a study of the pharmacokinetics of carboplatin administered in combination with the bradykinin agonist, ultrafilterable Pt was measured A rapid method for the assessment of high exposure to 239Pu in emergencies was developed. 239Pu was determined in 1 ml urine by magnetic sector ICP-MS with a desolvating introduction system, after solid phase extraction. LOD was 0.16 fg ml1 and RSD ranged from 2.2 to 3.7%. Results obtained on RMs were within 2.6% of target values (1–100 fg ml1) See Pd, ref. 139 304 139 5 138 135 140 305 139 142 143 138 134 135 137 136 141 158 139 Table 1 (continued ) Element Matrix Rh Biological and environmental samples Urine Serum, transferrin Biological samples Chinese herbal medicines Plasma Rh S S Sb Se Technique; atomisation; presentation Sample treatment/comments Ref. AE;ICP;ETV See Pd, ref. 138 138 MS;ICP;L MS;ICP;HPLC MS;ICP;L AF;HG;- See See See See 135 297 133 171 AA;ETA;L Calibration with the standard additions method or matrix matched standards gave significantly different results. No significant change of plasma Se content was observed after storage at 20 1C for 1 y Selenoproteins in red blood cells extracts and yeast were separated by gel electrophoresis and detected by LA-DRC-ICP-MS. Among reaction gases (CH4, CO, NH3, O2 and Ar–H2) CO offered the best performance. LOD was 0.07 mg Se g1 gel with single hole drilling and 0.15 mg Se g1 gel for ablation with translation Blood and serum samples were diluted with 10 g l1 Pd in 15% HNO3 and centrifuged prior to Se determination by Zeeman-effect ETAAS. LOD was 0.4 mmol l1. RSD was 4.5% (blood) and o1.7% (serum). Analytical recovery was 102.3% (blood) and performance in an External Quality Assessment Scheme for serum Se was within 1 SD of the target values The application of analytical techniques, such as NAA, ICP-MS, XRF and PIXE, to the investigation of Se metabolism and Se-proteins in mammals was reviewed Se species in urine were investigated by reversed-phase and ion-pair HPLC-ICP-MS and by CE-ES-MS. Urine was pre-concentrated by evaporation under N2 at room temperature (10-fold) or lyophilisation (100-fold) and extracted with CH3OH. Nebuliser performances (modified direct injection versus microconcentric combined with a cyclonic spray chamber) were compared. At least 10 Se compounds were separated. Se-methylselenogalactosamine was reported as the main species in urine of volunteers not supplemented with Se 145 A method was developed for the determination of Se in erythrocytes, after microwave-aided digestion. Measurements were carried out at mass 82 Total Se and SeMet were determined by ICP-MS (coupled with HPLC for the analysis of Se amino acids) in serum and prostate tissue from prostate cancer patients. Both were within expected normal ranges Serum Se levels decreased significantly after physical exercise only in subjects undertaking high physical activity Median Se levels in autopsy liver tissue samples from Greenlandic Inuit were higher than in samples from Danes (p o 0.0001), the difference attributed to higher intake of fish and sea mammals in the former By means of successive HPLC-ICP-MS and HPLC-ES-MS-MS, SeMet was identified as the main Se species extracted from yeast supplements, during simulated digestion processes, in in vitro gastric and intestinal digests Three methods of sample preparation (dilution, microwave digestion and ethanol addition), choice of internal standard (Sc, Rh, In) and spectral resolution were evaluated for the determination of Se in human plasma using magnetic sector ICP-MS. Ethanol addition (0.5% v/v) to a 1 þ 9 dilution of the sample gave the best results. ETAAS was used for comparison Se levels in toenail, determined by DRC-ICP-MS after microwaveaided closed vessel digestion, did not differ significantly between patients with prostate cancer and controls In multiple regression analysis, neonate serum Se concentration was significantly associated only with gestational age (P ¼ 0.012). Mother– child serum Se difference declined with gestational age and birth weight Samples of human milk (1 g) were digested with a mixture of H2SO4– HNO3–H2O2 prior to analysis by HGAFS. The digestion of 20 samples was completed in 3 h. LOD was 2.5 ng g1 and the relative expanded uncertainty (95%) was 10% 308 Se Red blood cell extracts, yeast MS;ICP;LA Se Blood, serum AA;ETA;L Se Biological samples MS;ICP;- XRF;;- PIXE;-;- Se Urine MS;ICP;HPLC MS;ES;CE 149,150 Se Erythrocytes MS;ICP;L Se Serum and prostate tissue MS;ICP;HPLC Se Serum AA;-;L Se Liver XRF;-;- Se In vitro gastric and intestinal digests MS;ICP;L MS/ MS;ES;HPLC Se Blood plasma MS;ICP;L AA;ETA;L Se Toenails MS;ICP;- Se Serum (cord and maternal blood) AA;-;L Se Human milk AF;HG;L Pd, ref. 135 Fe, ref. 297 P, ref. 133 As, ref. 171 35 306 307 309 310 53 172 144 83 311 146 J. Anal. At. Spectrom., 2005, 20, 323–369 347 Table 1 Technique; atomisation; presentation Element Matrix Se Blood plasma and erythrocytes AA;ETA;- Se Serum (RMs) AA;ETA;L MS;ICP;L Se In vitro systems, liver cytosol (rat) MS;ICP;HPLC MS;ES;- Se Serum Sr Urine AA;F;L AA;ETA;L MS;ICP;L Th Urine MS;ICP;L Ti Bone tissue PIXE;-;- Ti Ti Saline solutions Bone (rabbit tibia) AE;ICP;L XRF;-;- SIMS;-;- U Urine TIMS;-;- U Urine MS;ICP;L U U Urine Urine MS;ICP;L MS;ICP;L U Urine MS;ICP;L V Zn Zn Serum, transferrin Serum, nails Plasma, hair, urine MS;ICP;HPLC AA;-;AA;F;L MS;ICP;L Zn Zn Zn Liver tissue Serum Plasma, hair MS;ICP;LA AA;-;L AA;-;- Zn Serum, hair and lenses Prostate tissue AA;-;- Zn 348 (continued ) XRF;-;- J. Anal. At. Spectrom., 2005, 20, 323–369 Sample treatment/comments Ref. Se concentrations were determined by pulsed Zeeman-effect ETAAS in blood plasma and erythrocytes from newborns to assess their Se status according to birth weight and feeding type. Se intake was inadequate in bottle-fed, small for gestational age, infants Analysis performed by 3 independent laboratories using different digestion and determination techniques suggested that the Se target value of some batches of Seronorm Trace Element Serum Level 2 may be higher than stated Selenotrisulfides of glutathione, cysteine and homocysteine were synthesised and characterised by ES-MS and HPLC-ICP-MS. These Se species were determined by HPLC-ICP-MS in liver cytosol of exposed rats See Cu, ref. 296 152 Double focusing SF-ICP-MS provided a better LOD (3 pg l1) than ICP-MS with a hexapole collision cell (2 ng l1) for the determination of the radionuclide 90Sr. For lower levels, an extraction procedure with a crown ether resin was applied, giving a LOD of 0.4 pg l1 in urine with natural Sr concentrations of about 1 mg ml1. Recovery of spiked 90 Sr in urine ranged from 82 to 86% The levels of 232Th and 238U were determined in the urine of unexposed Jordanians from 6 cities. 238U, but not 232Th, levels correlated with age up to 60 years PIXE was used to investigate the release of metals in tissues surrounding metallic prostheses coated with biological glasses to prevent corrosion See Cr, ref. 132 No effect of surface roughness on Ti release from implants was observed in in vitro and in vivo experiments involving SRXRF and SIMS measurements of Ti in rabbit tibiae, 12 w and 1 y after implantation The amount of depleted U in the respiratory system of exposed soldiers was estimated from a mathematical model based on the urinary excretion of U isotopes U was determined in urine, 10-fold diluted with 0.14 mol l1 HNO3, by means of SF-ICP-MS. LOD was 0.2 ng l1 and RSD 5% at 10 ng l1. Some vessel materials gave rise to high blank levels. Urinary U concentrations were about 3–4 ng l1 in non-exposed individuals in Belgium and the Netherlands, but a few (o5%) exceeded 10 ng l1 See Th, ref. 160 To assess exposure of war veterans to depleted U, both U concentrations and isotope ratios in urine were measured by ICP-MS. High resolution (4000) was required to resolve a polyatomic interference causing apparent enrichment of 235U concentrations in urine 235 U : 238U isotope ratios, at U levels of 5–20 pg g1, were determined in urine, after sample decomposition and matrix separation, by means of a single-detector magnetic SF-ICP-mass spectrometer, fitted with an ultrasonic nebuliser. The uncertainty of measurement was evaluated as 2.5% (k ¼ 2) See Fe, ref. 297 See Cu, ref. 286 In a study of 67Zn kinetics in premenopausal women, Zn concentration and isotope ratios were determined in plasma, hair and urine after digestion with H2O2 and dissolution in 1% HNO3. The conventional cut-off value between normal and low Zn status (10.7 mmol l1 plasma Zn) was confirmed See Cu, ref. 37 See Cu, ref. 107 In pregnant women from Ankara (Turkey), both plasma and hair Zn levels decreased significantly during the 2nd trimester. Plasma (but not hair) Zn levels were significantly different between the ‘‘well nourished’’ and ‘‘poorly nourished’’ group See Mg, ref. 299 The combined measurements of serum prostate specific antigen and Zn in prostate tissue biopsies allowed improved separation between prostate cancer and benign hyperplasia 312 151 296 153 160 48 132 154 157 159 160 313 314 297 286 315 37 107 81 299 52 Table 1 (continued ) Element Matrix Technique; atomisation; presentation Zn Hair AA;F;- Zn Zn Zn Zn Zn Zn Zn Plasma, human milk Liver Serum Nails, serum Brain (rat) Erythrocytes Serum AA;-;L PIXE;-;AA;-;L AA;-;AA;-;L AA;-;AA;-;- Zn Zn Erythrocytes, serum Biological materials (human blood and hair, bovine liver and muscle) XRF;-;MS;ICP;LC Various Human organs and tissues Human biological samples Human central nervous system tissue XRF;-;- -;-;- Various (4) Clinical and biological materials, foods and beverages Biological fluids (urine, blood, human milk, bile, saliva, sperm) Plasma AA;-;- Various (4) Blood AA;-;- Various (4) Serum XRF;-;- Various (4) Serum, blood Various (4) Testis (rat) AA;F;L AA;ETA;L AA;;HG MS;ICP;- PIXE;;- Various (4) Urine AA;ETA;L Various (4) Serum AA;-;L Various (4) Skin (cancer) AA;-;L Various Various Various Various MS;ICP;XRF;-;- -;-;- Sample treatment/comments Ref. Occipital hair samples, collected from 34 New Zealander adults, were washed and digested with HNO3 prior to Zn determination by FAAS. There was no evidence of seasonal variation or influence of food intake, ethnicity, gender and hair colour See Cu, ref. 108 See Cu, ref. 54 See Cu, ref. 65 See Cu, ref. 288 See Cu, ref. 289 See Cu, ref. 290 The prevalence of Zn deficiency among children attending primary school in Turkey and its effect on anthropometric parameters were investigated See Cu, ref. 60 Zn isotope ratios were determined by high resolution multicollector ICP-MS, after sample digestion and purification by anion exchange chromatography. Comparison with SF-ICP-MS, indicated the presence of 35Cl21 affecting accurate 70Zn measurements. The variation of the 66Zn : 64Zn ratio in biological samples was investigated A review of recent advances of in vivo XRF methods and their applications to human organs and tissues was presented The use of ICP-MS for stable isotope tracer studies in humans was reviewed Synchrotron microbeam XRF was used for the topographic and quantitative analysis of selected elements in human brain and spinal cord autopsy samples from deceased patients with neurodegenerative diseases were compared with a control The published literature on the analysis of clinical and biological materials, foods and beverages using atomic spectrometric techniques for the year up to the end of October, 2003, was reviewed Analytical techniques and separation and/or enrichment methods for the determination of organic and inorganic environmental pollutants (and their metabolites) in biological fluids were reviewed 80 Plasma levels of Mg, Se and Zn (but not Cu) were lower in HlV1- and 2-positive Nigerians and decreased with CD4 lymphocyte count reduction In third-trimester gestational hypertension cases, blood Pb concentrations, but not serum Ca (ionised and total), Mg or Zn levels, were significantly correlated with blood pressure Cu, Fe, Se and Zn were determined by TXRF in serum samples from cancer patients and controls using the Compton peak as internal standard. These data were used to assess the capabilities of various artificial neural networks to classify individuals according to their health status Women, whose pregnancies were terminated as a result of a diagnosis of neural tube defects, had lower serum Se and Zn levels and higher serum Cu and blood Pb concentrations as compared to controls Stage-specific and age-dependent profiles of Cu, Mn, Se and Zn in rat seminiferous tubules were investigated by ICP-MS with a microdissection technique and in situ elemental imaging by micro-PIXE analysis As, Co, Mn and Ni were determined in urine by simultaneous Zeemaneffect ETAAS, using Pd as the chemical modifier and atomisation at 2100 1C. Pyrolysis was carried out at 1350 1C in two stages, the first using 5% H2 in Ar. Analysis of RMs gave 91–110% of the target values. LODs were 0.78 (As), 0.22 (Co), 0.054 (Mn) and 0.35 (Ni) mg l1 In patients with malignancies, chronic inflammatory response (assessed from plasma C-reactive protein concentrations) had no effect on the levels of Cu, Mn, Se and Zn In a prospective controlled study, the content of Cu, Fe, Se and Zn was determined in acid-digested tissue samples from patients with squamous cell carcinoma of the larynx or skin and controls. Fe and Se levels, but not Cu or Zn, were significantly lower in patients than in controls 108 54 65 288 289 290 162 60 161 44 22 46 1 2 70 67 56 66 316 61 69 68 J. Anal. At. Spectrom., 2005, 20, 323–369 349 Table 1 (continued ) Element Matrix Technique; atomisation; presentation Various (4) Serum MS;ICP;FI Various (5) Blood plasma AA;-;- Various (5) Arteries, cardiac valves Serum, milk, liver and kidney (dairy cows) Blood, serum AE;ICP;L Various (5) Various (5) AA;-;L Various (5) Carcass, liver, kidneys and brain (rat) AA;-;- Various (6) Heart, lung, kidney (rat) AA;-;- Various (6) Blood XRF;-;- Various (6) Pus (human) AA;-;L Various (6) Biological and environmental CRMs AE;MIP;HG/ ETV Various (6) Biological samples (SRMs) AE;ICP;FI Various (6) Brain proteins (human) MS;ICP;LA Various (7) Urine MS;ICP;L Various (7) Tendons, ligaments, cranial and spinal nerves AE;ICP;- Formalin-fixed brain tissue MS;ICP;L Various (8) Bone AE;ICP;- Various (8) Biological CRMs AE;ICP;L 18,17 Various (8) 350 AE;ICP;L J. Anal. At. Spectrom., 2005, 20, 323–369 Sample treatment/comments Ref. An on-line dialysis system coupled with FI-ICP-MS was devised to determine Cu, Pb, Se and Zn in serum samples using ID for calibration. Samples were incubated with enriched isotopes for 24 h at 36 1C. From 1 ml serum sample, about 70% of the electrolytes were removed after 10 min dialysis, thus reducing polyatomic interferences. The precision of isotope ratios was E1% for Cu and Zn and E2.5% for Se and Pb Trace element (Cu, Fe, Mn, Se and Zn) concentrations, malondialdehyde and total antioxidant capacity were evaluated in patients with childhood asthma The content of Ca, Mg, P, S and Zn in arteries and cardiac valves was assessed in relation to age and ethnicity Seasonal variations of Cu, Cr, Fe, Mn and Zn levels in biological fluids and tissues of dairy cows from a rural and an industrial area in Turkey were investigated In a study of levels of blood Cd and Pb and serum Cu, Se and Zn in samples from patients with coronary artery disease, blood Cd concentrations were significantly correlated with indices of left ventricular diastolic function Suckling rats, exposed to Pb, were treated with the chelating agent meso-2,3-dimercaptosuccinic acid (DMSA) and Ca supplementation. Ca, Pb and Zn were measured in their carcass and Cu, Fe and Pb in liver, kidneys and brain. Combined Ca and DMSA treatment during Pb exposure caused a greater reduction in tissue Pb than either treatment alone and had no effect on growth or essential element status After total body irradiation, Cu and Fe (but not Mg, Mn and Zn) tissue levels were significantly increased in kidneys, serum Ca and creatinine were elevated and electron microscopic analysis showed significant kidney tissue injuries Br, Ca, Cu, K, Pb, Rb, S and Zn were determined in whole blood samples from non-exposed Mexican subjects. Pb was determined after sample digestion and Fe extraction in order to improve LOD To investigate the host defence mechanisms mediated by the restriction of the bioavailability of Fe and Zn in suppurative infection, Ca, Cu, Fe, Mg, Se, Zn, lactoferrin and ferritin concentrations were measured in human pus HG and in situ preconcentration onto the (pretreated) interior wall of a graphite furnace were combined for the simultaneous determination of As, Bi, Ge, Hg, Sb and Se by MIP-OES with LODs of 3, 8, 15, 8, 20 and 10 ng, respectively, following high pressure or microwave-aided acid digestion of the samples The on-line separation and preconcentration of Bi31, Co21, Cr31, Cu21, Y31 and Yb31 prior to determination by ICP-AES was achieved using a FI system with a microcolumn of nanometer-sized TiO2 loaded with 1-(2-pyridylazo)-2-naphthol. The adsorption capacity of the system was 4.73, 18.57, 3.81, 6.14, 4.52 and 20.35 mg g1, respectively Al, Cu, P, S, Si and Zn in human brain proteins were determined in single protein spots by LA double-focusing SF-ICP-MS after separation of protein mixtures by two dimensional gel electrophoresis Two methods of sample preparation (dilution and acid decomposition) for the analysis of As, Cd, Cu, Fe, Pb, Se and Zn in urine were investigated. HCl concentration had a negative effect on signal intensity, partially compensated by the use of internal standards Age-related changes of the contents of Ca, Fe, Mg, Na, P, S and Zn in tendons and ligaments and of Ca, Mg, P and S in the optic, trigeminal, vagus, median, radial, ulnar, femoral, sciatic, tibial, and common peroneal nerves were investigated by ICP-AES 25 In a retrospective study of the concentrations of Cd, Co, Cu, Fe, Mn, Rb, V and Zn in formalin-fixed brain tissue from patients with neurodegenerative disorders and controls, significant differences were observed only for Cd and Zn Eight trace elements were determined simultaneously in Bronze age Cheshi human costa from China by ICP-AES after sample dissolution with HNO3 and HCl. Analytical recovery ranged from 87% to 107% and RSDs from 0.5% to 3.3% The solubilisation of biological CRMs with a solution of TMAH in CH3OH and ultrasonic shaking was reported as an alternative method of sample preparation for the analysis of major (Ca, K, Mg, Na) and trace (Cu, Fe, Sr, Zn) elements 72 19 252 74 317 64 58, 59 71 16 20 36 23 32 318 14 Table 1 (continued ) Element Matrix Technique; atomisation; presentation Various (8) Blood, serum, CSF and urine AE;ICP;L MS;ICP;L Various (9) Herbal medicine(Echinacea purpurea) AA;F;- AE;F;- Various (9) Teeth XRF;-;- Various (9) CRMs, cultured epithelial cells MS;ICP;L AA;ETA;L AA;F;L Various (9) Liver, bile (rat) AE;ICP;L Various (10) Brain (rat) XRF;-;- Various (10) Biological CRMs AE;MIP;Sl Various (10) Hair, nails, and skinscales MS;ICP;- Various (10) Bone (rat) AA;ETA;L MS;ICP;L Various (11) CSF XRF;-;- Various (11) Premature human milk, premature infant formulae MS;ICP;L Various (13) Plaque deposits in human arteries MS;ICP;- 28,29 Various (15) Medicinal plant AA;F;L Various (34) Hair, drinking water AE;ICP;MS;ICP;- Various (56) Blood, urine MS;ICP;L Various (68) Soft (animal) tissues (muscle, liver, kidney, lung and brain) MS;ICP;- Sample treatment/comments Ref. Al, Ca, Cu, Fe, Mg, Mn, Si and Zn were determined by ICP-AES or SF-ICP-MS in blood, serum, CSF and urine samples from patients with Parkinson’s disease and age- matched controls The content and seasonal variations of Ca, Cu, Fe, Li, Mg, Mn, Ni, Sr and Zn in different parts of Echinacea purpurea were evaluated by principal component and hierarchical cluster analysis The content of selected elements (Ca, Cr, Cu, Fe, Mn, Ni, Pb, Sr and Zn) in the roots and crowns of both primary and permanent teeth with caries disease was investigated Ca, Cd, Cr, Cu, Mg, Mn, Mo, Na and Zn were determined in cultured epithelial cells (Caco-2 TC7) by ICP-MS after closed vessel microwave digestion. Method performance was evaluated by analysis of CRMs and comparison with ETAAS and FAAS The changes in concentrations of Al, As, B, Ba, Cd, Hg, Ni, Pb, and Ti in the liver and bile of a hyperlipidemic rat model, after administration of Sempervivum tectorum extract as a therapeutic agent, were monitored The concentrations of trace elements (Br, Ca, Cl, Cu, Fe, K, P, Rb, Sn, Zn) in brain sections of 20 days old iodine-deficient and control rats were measured by SR-XRF. The effect of perfusion with a 0.9% NaCl solution before brain removal on the distribution of elements was discussed Slurry concentrations up to 1% m/v (particles o20 mm) were prepared in 10% HNO3–0.01% Triton X-100 and introduced by means of a Vgroove, clog-free Babington-type nebuliser. The analysis of CRMs for Ca, Cd, Cu, K, Mg, Mn, Na, P, Sr and Zn gave satisfactory results. RSD ranged between 7–11% As, Cd, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn were determined in (microwave-aided) digested samples of hair, nails, and skin-scales from subjects with As intoxication in West Bengal, India. Beside As, Mn, Ni and Pb levels were high compared with values from the literature The release of metals from different types of alloys implanted into rat tibia was studied. The tissues near the implant were lyophilised and acid-digested by microwave application. Fe concentrations were determined by ETAAS and other metals (Al, Co, Cr, Nb, Ni, Ta, Ti, V, Zr) by ICP-MS Br, Ca, Cl, Cr, Cu, Fe, K, Mn, Ni, Rb and Zn were determined in CSF of patients with amyotrophic lateral sclerosis and controls. Two methods of sample preparation were tested in order to improve LODs Al, Cd, Co, Cr, Cu, Fe, I, Mn, Pb, Se and Zn were determined, by ICPMS with an octopole reaction cell, in premature human milk samples and premature infant formulae after microwave-aided digestion. LODs ranged from 0.5 to 11 ng g1. The content of essential elements differed between human and formula milk The concentrations of Al, Ba, Ca, Cu, Fe, K, Mg, Na, P, Pb, S, Si and Zn in soft and calcified plaque deposits in human arteries were determined by ICP-MS. S levels (23–140 mmol g1) were interpreted as homocysteine. The Ca:P molar ratio was not explained as hydroxyapatite and other forms of Ca and P (e.g., phospholipids) may contribute. In the calcified deposits, the concentrations of Ca and P were at least an order of magnitude higher than those in the soft plaque 26 The total content and water soluble fraction of Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn were determined in different parts of Azadirachta indica (L) Neem by FAAS 34 elements were determined in drinking water and hair of women from an acid and an alkaline area in southern Sweden and their levels compared. Ca, Mo, Pb and Sr levels in water and hair were positively correlated After a firework explosion, two rapid screening methods were developed for the determination of 56 elements in diluted blood and urine. Quality control procedures and advantages and limitations of the methods were discussed Sixty-eight elements were determined by double-focusing, SF-ICP-MS in soft tissues, after microwave-assisted digestion with HNO3. RSD was o5% in most cases. Only for Cl were significant differences from the target values of CRMs observed. For elements at concentrations 42 mg g1, results were compared with ICP-AES 167 55 33 319 47 15 76 34 57 27 165 82 24 31 J. Anal. At. Spectrom., 2005, 20, 323–369 351 prevention of cancer trials between 1981 and 1996. Yeast-based materials with a high proportion of the total Se as SeMet produced larger increases in plasma Se in the subjects participating in the trials. However, when a yeast-based supplement was compared with simple synthesised SeMet alone, higher blood Se concentrations were given by the yeast material, pointing to other factors influencing the bioavailability. 3 Analysis of foods and beverages The following sections discuss developments with foods and beverages. In addition we include related topics such as the influence of processing and packaging on food items, which are not covered in any of the other Atomic Spectrometry Updates. Our last review was published in April 2004.1 Other reviews seen in the last year referred to characterisation of beverages with reference to elemental speciation and isotopic ratios174 and ten years of European experience with official methods for measuring stable isotopes in foods for the detection and/or prevention of fraud.175 Pyrzynska176 reviewed sample preparation and analysis in a discussion of adventitious contamination, regulatory limits and authentication of wine samples. Contamination of rice led to epidemics of severe Cd toxicity in Japan in the 1960s and 1970s. Ikeda et al.177 have reviewed the decrease in concentration of Cd in rice as a consequence of environmental improvements during the last 30 years. 3.1 Sampling and sample preparation 3.1.1 Extraction. Improved efficiency of analyte extraction when applying ultrasonication was demonstrated by several workers.178-183 Compared with non-sonication or with digestion, extraction was much quicker and simpler and gave similar results with a variety of sample types and analytes. Alkaline extractions were occasionally employed including the very simple expedient of using 0.1 M NaOH to obtain Se compounds from onion,184 but an unusual approach was taken by Vela and Heitkemper,185 who used trifluoroacetic acid at 100 1C in what was described as a ‘mild’ procedure to extract As from infant foods. Those with an interest in speciation are concerned with extraction efficiency and also with showing that there is no redistribution of the element during the extraction or on subsequent storage. These are features which appear to be influenced not just by the extraction procedure but also by the elements and food types that are investigated. Using a simple aqueous procedure only 68% of the total Se was obtained from mushrooms186 and as little as 9% from yeast tablets.187 A cold water extraction of lyophilised or fresh garlic yielded Se-allins (Se-alk(en)yl-L-cysteine selenoxides) that disappeared when stored at 44 1C. Curiously, the allin was stable when extracted from fresh onion.188 Four different extraction procedures were evaluated by Huerta et al.189 for the quantitative recovery of Se species from a BCR CRM cod muscle. The species were subsequently separated by reversed-phase and size-exclusion HPLC and Se detected by ICP-MS with an octopole reaction system using H2 to eliminate isobaric interferences from Ar species. The highest recoveries of Se were obtained using enzymatic digestion, whereas ‘soft’ extraction with CH3OH– HCl recovered only 5% of the total tissue Se. With three consecutive 50% v/v CH3OH–HCl extractions, quantitative recovery of As species from rice, fish and chicken was possible. The species in the rice extracts were stable for at least three months whereas AB in the other samples was gradually transformed to DMA.190 Extractions using CHCl3–CH3OH were successfully employed to obtain stable As species from baby foods191 and nuts.192 Attempts to extract As species from peanut butter into CHCl3 with CH3OH were unsuccessful but much better recoveries were given with 2-butoxyethanol.183 352 J. Anal. At. Spectrom., 2005, 20, 323–369 Enzymic hydrolysis to release As species from the protein matrix of food samples was occasionally implemented.191,193 3.1.2 Digestion. A method that reduced the residual C to less than 1.3% was developed by Flores et al.3 Samples were wrapped in paper, placed on a quartz holder and inside a quartz vessel. After addition of an NH4OH solution to the paper, the vessel was pressurised with O2 and microwave radiation applied for 20 s at 1400 W. When reflux with HNO3 was then applied the residual carbon was less than 0.4%. Since most analytical techniques have long been able to cope with samples having much greater levels of carbon the requirement for this procedure is unclear. Variations on the typical microwave-assisted acid digestion theme were presented. Trevizan et al.4 described a PTFE support so that bovine liver within glass cups could be digested by acid vapour within a microwave oven. In the method developed by Chen et al.,127 samples were digested using TMAH with focussed microwave heating and the methylmercury extracted with n-heptane after addition of Cu21 and derivatisation with sodium tetrapropylborate. Simple immersion of biscuit samples in acid with C2H5OH, at room temperature, was reported to provide results for Fe and Zn by FAAS that were comparable to those achieved after digestion with heating.194 By comparison, a mixture of H2SO4–HNO3–H2O2–HF–V2O5 was taken to digest vegetables before measuring Se.195 3.1.3 Preconcentration. No major innovations for analyte enrichment were introduced in the last year. One piece of original work involved the use of silica membrane discs modified by 1-hydroxy-2-(prop-20 -enyl)-4-(prop-20 -enyloxy)9,10-anthroquinone to trap Cu21 ions from a range of SRMs. The adsorbed analyte was then eluted with HNO3 and an enrichment factor of around 400 was reported.8 Less spectacular results were obtained when tap water was taken through a column of naphthalene–methyltrioctlyammonium chloride, which adsorbed Cd as the CdI42 ion. After optimisation of pH, iodide and flow conditions a 40-fold preconcentration was achieved and the LOD using FAAS was 0.6 ng ml1.196 Other applications involved conventional column approaches either off-line or on-line in FI pathways. Ion-exchange resins, activated carbon and chelating resins were all employed as solid phases with measurements of metals in drinking water, beer and wine.196-200 Fernandes et al.200 evaluated C18 bonded silica gel and powdered polyethylene as sorbents for Cd, Cu and Pb in wine, with ammonium diethyldithiophosphate as the complexing agent. Slightly better performance was found with the C18 for Cu and Pb and with polyethylene for Cd. A preconcentration factor of more than 300 was reported with a simple cloud point extraction applied to the measurement of Pb in water.201 3.2 Speciation In contrast to previous years most of the published work referring to speciation concentrates on the results of analyses rather than technical developments. Such work is discussed in later sections of this review. Furthermore, much of the work relates to the sample preparation and is designed to avoid changes during extraction (see 3.1 above). Yet again it is As and Se that dominate the interest in speciation. While many of the speciation procedures involve LC-ICP-MS some other interesting approaches were attempted. Ecinar et al.202 opted for SEC with combined matrix-assisted laser desorption ionisation TOF-MS and ES-quadrupole-TOF-tandem-MS to determine selenoproteins in yeast-based food supplements. Organoselenium species in yeast, mustard and garlic were separated by GC and MIP-AES using a specially designed system that also involved SPME.203 This method gave results within 3 min with sub-ppb LODs. Reversed-phase HPLC and SEC were used to separate Se species from cod muscle. Measurement involved post-column ID and an octopole reaction cell with determination of the 78Se : 77Se ratio.189 Simon et al.204 were interested in the effects of the mobile phase on post-column photooxidation and HGAFS of As species from fish and seafood samples. They found that widely used aqueous pyridine solutions inhibit post-column conversion to detectable As, with loss of sensitivity. Revised conditions were shown to give good separation of AB, AC, TMAO and TMI with LODs of 4–12 pg. In an investigation of human milk, Mn compounds were identified by SEC-ICP-MS.123 The procedure does not allow for an impressive sample throughput as the main peak appeared at 95 min. A classically simple method for differentiating the (IV) and (VI) oxidation states of Se and Te ions was reported by Cava-Montesinos et al.205 Milk slurries were sonicated with aqua regia and immediately measured by AFS to determine the quadrivalent species. Similar samples were reduced using KBr to determine total Se and Te concentrations. 3.3 Applications using hydride generation Arsenic was measured in fish and coffee beans by FI-HGAAS, with a method validated using CRMs. Reagent concentrations, atomisation temperature, injection volume, reaction coil length and carrier flow rate were all optimised. Interference from other ions was masked with ascorbate and KI in HCl. The method had an analysis rate of 135 samples h1. Several workers have reported on the analysis of Chinese medicines using hydride generation AFS for As170,206 and As and Sb.171 All included details of how the procedures need to be optimised to give satisfactory results. For the analysis of milk, also by AFS, Cava-Montesinos et al.207 found that KBr was the preferred reductant for Se and Te while ascorbate–KI was better for As and Sb. Either reductant could be used for Bi. 3.4 Applications using flame atomic absorption spectrometry In the 2004 ASU1 we mentioned an innovative accessory that produced a dry aerosol for introduction of solid powdered CRMs into the flame. The same workers have now reported on the use of this technology for the measurement of Cu in medicinal plants by flame atomic absorption spectrometry. The LOD was 1.2 mg g1 from a 1 mg sample and results were not different from those reported after digestion and conventional FAAS.6 Aleixo et al.208 measured Cd and Pb by beam injection FAAS. In this technique a nickel-base alloy tube is positioned above the burner, in the light path. A pressurised aerosol of a fixed volume of a liquid sample is forced into the tube, through a small inlet, where atomisation takes place. Samples were prepared by HNO3 extraction from dried powdered foods. The LODs were 0.03 mg g1 and 1.6 mg g1, respectively, representing improvement factors of 20 and 26. Good agreements with certified values were reported for several RMs. Zinc was determined in milk powder and infant formula, using an FI system that included the sample dissolution process179 and gave an LOD of 0.3 mg g1. 3.5 Applications using electrothermal atomic absorption spectrometry There are few reports of non-graphite atomisers being used. Amin et al.209 employed a molybdenum tube for measuring Cd in vegetables. Slurry samples were prepared in 10% glycerol and thiourea was used as the modifier. An LOD of 13 fg was obtained. The tungsten coil atomiser has slipped in popularity in recent years and just one application was seen. Measurement of As in an oyster CRM was described and Ir or Rh were the preferred modifiers.94 Optimisation of all conditions was presented. Aleixo and Nobrega210 showed that dilution of milk with a mixture of tertiary amines (10% CFA-C) improved the handling by the autosampler with a useful effect on repeatability. Details of modifier, heating temperatures and calibration were also reported. The positive features of permanent modifiers were further exploited, particularly using Ru alone or with Ir or Zr. A Brazilian group investigated such modifiers for measuring different elements in cachaca, a spirit derived from sugar cane,211,212 and in drinking water.213 They reported the effects on LODs, characteristic concentrations and peak shapes. However, they noted that for Al, Cd and Pb the matrix of cachaca itself acts as a modifier and addition of other chemicals is not necessary.212 Calibration methods were investigated for the measurement of Mn in vitamin-mineral tablets by a solid sampling assay.214 Experimental parameters were optimised and calibrations with aqueous standards, aqueous standards added to solid sample and against solid CRMs were compared. The best results were obtained using the aqueous standards with results that were in good agreement with those determined after acid digestion. Because of the volatility of Hg, measurement of this element by ETAAS usually warrants attention to see how the drying and ashing were accomplished without loss of analyte. For measurement in wine Karadjova et al.215 complexed the metal with APDC and an LOD of 0.2 mg l1 was reported. 3.6 Applications using inductively coupled plasma-mass spectrometry Two projects were concerned with non-standard sample introduction methods and both involved the analysis of rice flour. In one, laser ablation was used with no sample preparation required. Three different CRMs were taken for calibration in the measurement of Cd and no interferences were observed.216 In the second piece of work ETV was chosen with Cd, Cr, Cu, Hg and Pb being measured.217 Samples were prepared as slurries and the analyte ions were transported through a DRC containing NH3. Ion signals were enhanced by addition of ascorbate to the samples. Both ID and standard additions were used for quantitation and each approach gave results that were within the certified ranges. An octopole reaction cell was used to remove polyatomic interferences when measuring 11 essential and toxic elements in premature human milk.27 The organic matrix was destroyed by digestion prior to analysis. Operating parameters (octopole bias and quadrupole bias) were optimised so as to form a ‘potential energy barrier’ between the cell and the quadrupole mass spectrometer and the LODs were from 0.5 to 11 ng g1. Multiple collector ICPMS was employed to determine Sr isotope ratios in Emmentaltype cheeses. 83Kr, 82Kr and 85Rb were measured to correct for interferences. The 88S : 86Sr, 82Sr : 86Sr and 84Sr : 86Sr ratios were determined with precisions (RSD) of 0.002–0.01% and the measurement uncertainty was calculated to be 0.016%.218 Apart from these studies there was remarkably little to report that was in any way new. 3.7 Applications using other analytical techniques Resonance ionisation MS, with an electrothermal atomiser, was applied to the measurement of Co in the juices from a number of different fruits.219 The wavelength chosen was 298.71 nm and the LOD was less than 5 pg. A calibration range of up to 1 ppb was produced and the amounts of Co in 5 ml of pear, apple and mandarin orange juice were found to be 150, 45 and 100 pg, respectively. New applications of XRF continue to appear. A Brazilian group used SRTXRF for multielement analysis of wine348 and mineral waters.220 Samples of about 10 ml were simply dried on a perspex holder and irradiated for 200 s. Food samples were analysed by TXRF,178 EDXRF221 and WDXRF222 following J. Anal. At. Spectrom., 2005, 20, 323–369 353 minimal sample preparation. The results compared well when assessed against other analytical techniques. In addition to determining the hydride forming elements, AFS is ideally suited for measuring Hg following cold vapour generation. Cava-Montesinos et al.223 developed a procedure which allowed a rapid analytical rate (70 samples h1) and used about 15% of the reagent volumes compared with conventional techniques. The LOD was 0.011 ng g1 and the RSD was 3.4% at 0.3 ng g1 in milk. An LOD of 0.03 ng ml1 was reported for a method that involved digestion of medicinal plants in closed vessels prior to AFS.169 Gomez-Ariza et al.224 used AFS coupled to capillary GC to measure methylmercury in seafoods. Two procedures were investigated and the most effective parameters determined. One, where small samples were taken and both the inorganic and methylmercury were ethylated, required no further clean up. In the second, using larger samples, alkylated species were extracted into organic solvent. Few reports mentioned atomic emission spectrometry and where this was so, with ICP225 or with MIP,14,15,203 the technique was incidental to the sample preparation. 3.8 Progress for individual elements 3.8.1 Arsenic. There was much work which simply reported on the concentrations of As in different foods and total diets226,227 for which HGAFS and HGAAS were employed. Chemical modifiers for use with the tungsten-coil atomiser were investigated: Ir and Rh were effective but Pd was not.94 However, most of the recent analytical literature was concerned with aspects of speciation; the extraction, chromatography and measurement. The usual detectors are ICP-MS with ion exchange columns, either anion- or mixed anion/cationexchange columns used for the separations. With most systems the species AsIII, AsV, MMA, DMA and AB were differentiated, and while most or all were present in foods the proportions varied considerably.183,190,192,193,228,229 It was suggested that the ratio between the AsIII and AsV in soil or water influences the concentrations and species found in the foods.228 Interest in the As content of infant foods was evident. Many contain very low concentrations, less than 24 ng g1,185 mainly as AsIII, AsV and MMA. However, when foods contained fish AB was detected and the concentrations were much higher at 2–3 mg g1.191 Since AB is the main As species in marine fish this is not surprising, an observation confirmed by Kato et al.,230 who analysed sardines, Japanese sandfish and squid. However, when they examined the fish sauces prepared from these they found that most had been converted to DMA. The concentration of As in drinking water reduced on storage due to the formation of As/Fe precipitates.231 Addition of EDTA–CH3COOH prevented this loss. 3.8.2 Lead. There were no analytical developments to mention and relatively few reports of measurements in foods. One interesting study was of the toxicokinetics of Pb in blood and cows milk.232 Animals were given a single i.v. dose of Pb at differing intervals (up to 20 h) after the onset of light and specimens were collected at time points thereafter to calculate the elimination half life and area-under-the-curve. Data showed that transfer of Pb into milk differs throughout the day. Samples of fish from Nigeria had Pb concentrations that were associated with proximity to the roads near the markets where they were sold.233 Total dietary intakes in children and adults were determined in Germany234 and Pb in illicit alcohol in the USA was reported.235 3.8.3 Mercury. Measurement of Hg in wines was described in two papers. In one, a special reactor was designed to pretreat the samples with O3 prior to analysis by FI-CV-AAS.236 354 J. Anal. At. Spectrom., 2005, 20, 323–369 This provided for a rapid determination compared with other preparative methods. The second involved complexation with APDC and extraction into an organic solvent followed by ETAAS.215 The LODs for the two methods were 0.5 mg l1 and 0.2 mg l1, respectively, while the first was a little more precise. Gas chromatography was included in methods for measuring methylmercury in fish and seafood. Chen et al.127 elected to use microwave assisted TMAH extraction and derivatisation with sodium tetrapropylborate. The product was extracted into n-heptane and analysed by GC-MS with an LOD of 40 ng g1. Two methods applicable to different concentration ranges were developed by Gomez-Ariza et al.224 In the first, for 0.75– 10 mg Hg g1 dry weight, clean-up was not necessary because of the small sample weight required. Both inorganic Hg and methylmercury were ethylated, methylmercury separated by capillary GC and the Hg detected by AFS after pyrolysis. The second method was similar, but for lower concentrations, 6– 1000 ng Hg g1 dry weight, and required a clean-up stage to remove interferents from the matrix. The appropriate method could be selected after a preliminary screen for total Hg, as most of the Hg in seafood is methylmercury. Optimal parameters for both approaches were evaluated and the methods evaluated by analysis of two CRMs. The normal daily intakes of Hg by children living in a German community were measured as part of an extensive project.226 3.8.4 Selenium. As in recent years Se is the element that attracts the greatest attention, with the majority of reports referring to speciation and most of these involving the Se-rich varieties of either yeast or garlic (see section 2, above). Despite the plethora of published methods from the last five years, yet more are appearing. In addition to HPLC with ICP-MS, TOFMS, ES-MS,202 GC-MIP-MS203 and CZE-ICP-MS187 have all been employed. One of these reports was essentially a review of all the analytical phases for a speciation analysis.202 However, there are now also reports where the emphasis is on the measured concentrations in foods rather than just dealing with the analysis itself. The impetus to this appears to be the interest in Se and the prevention of cancer. Certain foods are being prepared with enriched concentrations and the clinical studies require knowledge of the concentration and of the forms of Se that are present.173,188 Total dietary intakes of Se were reported for children in Germany226 and Se concentrations were given for infant milks,237 vegetables,195,238 and various other foods.239 3.8.5 Other elements. There were few reports of other elements to which attention needs to be drawn. Foods available in Slovenia were analysed by ICP-AES to determine Al.240 High concentrations were found in mussels, parsley and lamb’s lettuce (300–400 mg kg1 dry weight), but most items contained less than 30 mg kg1. These authors also showed, like others before them, that Al is leached from cookware into acidic foods. It is not often that Co is determined in foods. Saulea et al.241 analysed a large number of different foods and beverages for this element using ETAAS. Samples were prepared by acid digestion and standard additions were necessary for calibration. It has been shown in the past that soy-based infant milks and foods contain very high concentrations of Al. Cockell et al.242 now report that Mn is present in soy and rice infant beverages. They calculated that the daily Mn intake for infants up to 1 y of age is at or above the Tolerable Upper Intake Level and warn that such beverages should not be used as they may present an increased risk of neurological damage. 3.9 Single and multi-element analysis of foods and beverages 3.9.1 Dietary intake studies. Two further publications have appeared from the group who collected 7-day duplicate diets from children in Amrun, an island at the north of Germany.226,234 The intakes of As and Hg were 0.89–6.75 and 0.06–0.62 mg kg1 body weight week1, while Pb was 0.04–1.6 mg kg1 body weight d1, all well below WHO limits. However, the age-related targets set by Austrian, German and Swiss Nutrition Councils for Se intakes were not met in a significant proportion of the children. These workers also measured Pb in the diets of children and adults from a highly industrialised part of Germany and the intakes were similar to those of the Amrun children.234 In a third paper, this group determined the very low Au and Pt intakes in children aged 14–83 months. Concentrations of Pt were slightly higher in supermarket products compared with garden grown vegetables.243 Akhter and co-workers measured Ca, Sr and U in Pakistani diets244,245 as part of a programme related to radiation protection. According to the recommendations of the International Commission on Radiological Protection (ICRP), typical diets have adequate Sr but only about 60% of the necessary Ca. The U in food, at 2.3–11 ng g1 dry weight, gives daily intakes that are said to be 40% higher than the ICRP value but within the safe dose limit for radioactivity.245 The Cu, Fe and Zn contents of foodstuffs were evaluated in Nigeria246 and in Chile.247 The foods examined and the concentration units reported were not the same so cannot be easily compared. The Chilean study was particularly thorough and daily intake data were reported for all three elements in age related groups from infants through to 64 years, for both male and female subjects. The authors noted that infants and women of reproductive age are liable to Fe deficiency, all groups are at high risk of Zn deficiency and adults have a moderate risk of Cu deficiency. In a more ambitious project nine elements were determined in foods consumed in Rio de Janeiro.248 No problems were evident for toxic elements but Cr and Zn intakes were below the recommended allowance. It was noted that black bean is a good source of Cu, Mn, Ni and Zn. Daily intakes of Cr, Ni and Se by adult Poles were found to be 60–90, 1.24–166 and 54–99 mg, respectively.249 In another Polish study, B was determined in diets of children.250 There are few previous indications relating to this element in foods, making this a useful source of information. The daily intakes were 1.01 and 1.2 mg for pre-school children and teenagers, respectively. Ikeda and colleagues177 presented a review of dietary exposure to Cd, as published during a period of more than 30 years since the early 1970s, in environmentally polluted and non-polluted areas of Japan. Following soil remediation, concentrations in Japanese rice had fallen from around 600 mg d1 to less than 30 mg d1. Nevertheless, at the time when the review was puiblished (2004), it was still higher than in rice from other parts of Asia.177 3.9.2 Human milk and infant foods. Mechanisms for the transfer of essential and non-essential elements into human milk are still poorly understood. Domellof et al.108 found that Cu, Fe and Zn in human milk have no association with the maternal status of these elements and suggested that this indicates active transport in the breast tissue. In addition, they compared the Cu, Fe and Zn concentrations in samples from Swedish and Honduran mothers. They found that the Fe was higher but Cu and Zn were lower in the Swedish samples. By contrast, the concentrations of Hg and Pb in human milk were found by Dorea117 to be directly proportional to those in maternal blood, indicating no control of movement across the mammary membranes. Concentrations of Se in human milk were reported from Spain237 and Italy146 and were similar to those found in other countries. Distribution of Mn among the protein and lipid fractions in human milk123 and a panel of more than 10 elements in premature milk251 showed that there are considerable differences within milk in addition to the temporal changes that have long been recognised. The work on As in infant foods185 and Mn in soy and rice beverages242 was described above (sections 2.8.1 and 2.8.5, respectively). 3.9.3 Milk and dairy products. An investigation of Cr, Cu, Fe, Mn and Zn in cows farmed in an iron–steel processing region and in a non-industrialised area showed that, as for human milk, the concentrations of essential elements in bovine milk are not affected by maternal status.252 Much more important are the changes that occur during processing, as shown by Closa et al.253 Skimming led to increases in the concentrations of the eight minerals measured, especially of Ca. Further increases took place in the production of yoghurt following the addition of milk solids, evaporated milk or ultrafiltrates. The normal concentrations of As, Bi, Sb, Se and Te in Spanish,207 and of Cd, Cr, Cu, Pb, Se and Zn in Cantabrian (Italy) milks,254 were reported. 3.9.4 Wheat, flour and rice. Fifteen different elements were measured in wheat purchased in Egypt, Saudi Arabia, Yemen, Oman, Dubai and Australia.255 The concentrations of 36 elements, later limited to 15, in varieties of barley were determined to investigate associations with genotype, plant stage of growth, and soil type.256 Inorganic As in 40 samples of American white rice ranged from o0.025 to 0.271 mg g1 wet weight.257 Interesting analytical developments with ICPMS, where rice flour CRMs were used to validate the work, were mentioned in section 2.6. 3.9.5 Vegetables, nuts and fruits. Over the years, transfer of Pb from soil and dust to crops has been measured in several studies. Although pollution from petrol and industrial sources is now reduced, this topic is still studied, yielding essentially the same conclusions. The most recent piece of work found highest concentrations in root (root : soil ratios of 0.02–0.51) with less in shoots and very little in leaf or vegetable fruit. The ICP-AES technique used, however, had an LOD of 10 mg g1 dry weight, and may not be sufficiently sensitive to provide as complete a set of information as is really required.258 Analysis of shiitake, the most popular edible mushroom in Eastern Asia, showed that Se was present as SeMet, possibly bound to a large soluble protein.186 The As in different types of nuts was measured.192 Most was present as AsIII and AsV, 0.07–12.7 and 0.5–4.3 ng g1, respectively, while As as MMA was at 0.1–1.3 ng g1. Very low concentrations of MMA were found, up to 0.5 ng g1 in pistachio nuts. At 0.0462 mg 100 g1 and 0.046 mg dl1, the Zn in grapes and grape juices consumed in Spain is lower than reported in popular food composition tables. The mean Cu values in the same samples were 0.0515 mg 100 g1 and 0.0063 mg dl1.259 3.9.6 Fish and seafood. As part of a long-term monitoring programme 18 elements, including As, Cd, Hg and Pb, are being measured in economically important fishstocks from the Barents, North and Norwegian Seas. The programme commenced in 1994 and is expected to continue until at least 2010. No undue concentrations have been found.260 Conversion of AB to DMA during the production of fish sauce was referred to in section 2.8.1 but a study of fish caught in an estuary in Thailand demonstrated that in some situations inorganic As can be present in vivo.193 Water draining from a tin mining area was contaminated with As and sediments had total As concentrations up to 269 mg g1 (dry weight), with some AsIII but mostly as AsV. Fish contained AB, as expected, but inorganic As was also found. Dried fish sold in an open market in Nigeria had Pb at 8–12 mg kg1, caused by contamination from adjacent traffic exhausts.233 J. Anal. At. Spectrom., 2005, 20, 323–369 355 3.9.7 Drinking waters and non-alcoholic beverages. A new twist has been added to the problem of high concentrations of As in drinking water in Bangladesh. It has been suggested, on the basis of in vitro work, that Sb may be a confounder in the development of As toxicity. However, analysis of 245 well water samples, with As concentrations of o1 to 747 mg l1, all had Sb at o1 mg l1, suggesting that this potential danger is not relevant to this region of the country.261 High concentrations of As in drinking water are found in other countries and values of up to 3 mg l1 were reported from Turkey.262 This compares with a maximum allowable level of 0.05 mg l1. The importance of appropriate conditions for collection and storage was demonstrated by studies in the USA and was discussed in section 2.8.1. A number of popular soft drinks manufactured and sold in Pakistan were analysed by Wattoo et al.263 Of the 15 elements measured Al, Cd, Fe, Ni and Pb were found at concentrations above the WHO drinking water limit. Many also showed evidence of microbiological contamination. Selenite and selenate in drinking water were separated and individually measured by ETAAS in an FI system developed by Stripeikis and co-workers.198 Measurement by ETAAS made use of Ir as a permanent chemical modifier. A systematic study with Ir, Rh, Ru and Zr, to determine the best permanent modifier for each element (Al, Cd, Cr and Pb) in drinking water, was carried out by Pereira et al.213 It was found that Rh was best for Cd and Cr while Zr was appropriate for Al and Pb. 3.9.8 Alcoholic beverages. Analysis of wines for purposes of demonstration or investigation of their provenance is discussed in section 2.11, below. The way in which the vinification processes alter the trace element composition of wines has been described in previous Updates. A further study has looked at the preparation of German white wines.264 Total Sr concentrations increased in Portuguese wines throughout each stage of the process.265 It was also shown that the 87Sr : 86Sr ratio remains unaltered and is identical to that of the soil in which the grapes were grown. Following reports of increased blood Pb concentrations in subjects drinking illegally produced spirits (moonshine), 115 samples collected from nine states in the USA were analysed. Concentrations found were from 0 to 53 200 mg dl1, with a median of 44.0. The limit proposed by authorities of 300 mg dl1 was exceeded in 28.7% of the samples. It was calculated that sustained intake of large amounts of many examples of moonshine would cause blood Pb concentrations to exceed 25 mg dl1.235 By contrast, the Pb in Korean wines, at 5–87 mg l1 appears quite innocuous. Concentrations of Cd were also very low at o0.1–3.0 mg l1.266 In samples of Brazilian sugar cane spirit, Cachaca, the concentrations of Al, Sb, Cd and Pb were r22.4, r39.1, r0.7 and r526 mg 11, respectively, and 0.64–1.53 mg l1 for Cr.211,212 3.9.9 Other foods. Trace elements in various other foods were reported. A large number of herbs, spices and condiments from Turkey267 and Sri Lanka221 were analysed to determine whether the nutritional properties might be related to their mineral content but no unexpected results were obtained. The usual major elements were found at large concentrations while trace elements were low. High levels of Al were reported in a number of samples but contamination-free determination of this element requires considerable care and attention. Eggs as a source of trace elements are not often considered. Some quite high concentrations were determined in a study from Nigeria and the authors drew particular attention to the Cd and Pb.268 The As species in chicken meat and in peanut butter were determined in two separate projects. Both samples were being investigated as candidate RMs. The chicken meat contained DMA and AB at concentrations of 106 and 37 ng g1, 356 J. Anal. At. Spectrom., 2005, 20, 323–369 respectively229 while, in the peanut butter,183 AsIII, AsV, MMA and DMA were measured at 1.6, 6.3, 4.9 and 6.1 ng g1. 3.10 Reference materials and collaborative trials Very little work relating to new food reference materials has been presented. A rice material was prepared for the International Measurement Evaluation Programme (IMEP) where Cd, Cu and Pb were certified using ID-ICP-MS as the measurement technique.269 It was found that a digestion procedure with HF was necessary to ensure complete solubilisation. The SI-traceable concentrations found were 14.39 106 mol kg1, 44.31 106 mol kg1 and 2.034 106 mol kg1 for Cd, Cu and Pb, respectively. Measurement uncertainty was estimated according to ISO guidelines and the calculated combined uncertainties were also reported. The rice powder was observed to be hygroscopic and a second series of measurements were carried out after equilibration of the material with ambient moisture conditions. Results from the analysis of chicken meat and peanut butter candidate RMs were discussed in the previous section (3.9.9). 3.11 Packaging and cooking It has long been recognised that packaging materials may contribute considerable contamination to foods. Modern materials are less likely to offer risks to health but it is necessary to be vigilant. A classic situation is that of foods in tin cans and instances of gastrointestinal disturbances are well known. Although cans are now coated with a lacquer, some migration is possible with acidic foods. Using randomised double-blind crossover studies, Boogaard et al.270 compared the incidences of adverse gastrointestinal effects in volunteers given different concentrations of Sn either as tin(II) chloride added to tomato juice or Sn migrated from cans into tomato soup. Their findings indicated that it was the chemical form of Sn rather than the elemental concentration that determined the severity of adverse effects. Some 50–60% of Sn in tomato juice was in the form of low Mr species, whereas this fraction constituted only 31–32% of Sn in the tomato soup. A dose relationship was only observed for SnCl2 added to tomato juice and no clinically significant adverse effects were observed in volunteers given that Sn migrated from cans. They considered that the current recommended levels of 200 mg kg1 Sn for canned beverages and 250 mg kg1 Sn for canned food are safe levels for adults in the general population. Polyethylene materials are used extensively for packaging many types of foods yet the content of potentially harmful elements has not been well documented. Three such materials were digested using HNO3 and H2O2 before analysis for As, Cd, Cr, Pb and Sb by ICPTOF-MS.271 The highest concentrations obtained were 0.33 mg kg1 Cr, 1.06 mg kg1 Pb and 1.81 mg kg1 Sb. Other elements were below the LODs and in some samples none of these 5 elements could be detected. The effects of soaking and boiling peas on concentrations of Mo, Ni, P and Zn were thoroughly investigated. Soluble high Mr species were lost so that while the total concentrations were reduced, the overall proportion of ionic and labile complexes increased.272 Yet another study confirmed the observation that acidic foods cooked in aluminium utensils will extract the metal. This time sauerkraut and sour turnips were shown to be the villains.240 3.12 Authentication of foods: provenance and origins Determining the elemental composition of foods and beverages to authenticate their origins has been regularly reported in these reviews, especially for wines. Following from the original measurements, concentration patterns of specific suites of elements and/or isotopes have been proposed as being indicative of the Table 2 Foods and beverages Element Matrix Technique; atomisation; presentation Al Sugar cane spirit AA;ETA;L Al Foodstuffs, cookware AE;ICP;L As As Drinking water Foods -;-;L AA;F;L As Fish, rice, vegetables AA;HG;L As Fish, shellfish AF;HG;LC As Baby food AA;HG;HPLC AA;ETA;L As Clam, oyster CRM AA;Tungsten coil;L As Peanut butter MS;ICP;IC As Nuts MS;ICP;IC As As Carrots, trout Fish, crustaceans MS;ICP;HPLC MS;ICP;L As Chicken, fish, rice MS;ICP;HPLC As As Chicken White rice MS;ICP;LC MS;ES;L As Infant food and formula MS;ICP;L As Food AA;HG;FI As Fish sauce MS;ES;LC Au Foods -;-;- B Diets AE;ICP;L Br Cereals MS;-;GC Ca Cheddar cheese AA;-;L Ca AA;-;L Ca Diets, faeces, sweat, urine Diets Cd Tap water AA;-;L AE;ICP;L AA;F;L Cd Sugar cane spirit AA;ETA;L Sample treatment/comments Ref. Al, Cd and Pb were determined with and without permanent chemical modifiers such as Zr–Rh and Ir–Rh. The Al and Cd results were better without the use of the modifiers Al was determined following microwave digestion in a range of Slovenian foodstuffs. Cooking sauerkraut and sour turnip in Al cookware induced a significant rate of leaching 7 preservation methods for AsIII and AsV were discussed 7-day dietary intake of As, Hg and Se was studied for children living on the North Sea island of Amrum, Germany. The Se intakes were below recommended levels in a number of cases As part of the ongoing As contaminated water crisis in Bangladesh, 100 samples of foods potentially affected by, for example, irrigation, were analysed. Variable results within and between species were recorded An on-line decomposition method based on UV photolysis was used to determine AB, AC, TMAO and TMI. The absolute LOD was 4–12 pg As H2O–CH3OH–CH3Cl and an enzymatic method were used to extract As. AB was the major species present and there was no evidence of degradation over shelf life or as a consequence of freeze-drying the foods Ir, Pd and Rh were evaluated as chemical modifiers in tungsten coilETAAS. Pd was not satisfactory, but Ir and Rh yielded 1.4 and 1.9-fold increases in sensitivity, respectively. When applied to the actual samples, Rh offered the superior performance Following extraction with 2-butoxyethanol, As was speciated using HG-IC-ICP-MS. AsIII, AsV, MMA and DMA were found in commercial samples Some of the difficulties in analysing nuts were discussed, e.g., hardness, high lipid content, sample heterogeneity. Ultimately it was necessary to determine As and its’ species in an oil fraction and the defatted sample AsIII, AsV, DMA and AB were determined Anion-exchange HPLC, employing a step elution, was used to speciate AsIII, AsV, AB, DMA and MMA in trypsin extracts The efficiency of H2O, H2O–CH3OH and H3PO4 at extracting As species was evaluated. The best recoveries were obtained for 3 consecutive extractions using 1 : 1 CH3OH : H2O DMA and AB were found to be present As levels ranged from o0.025 to 0.271 mg g1 (wet-mass basis) in samples from the USA Reassuringly, total As levels in a range of samples were low, the highest concentration being 320 ng g1 dry weight in cereal based products. The samples were also speciated, and inorganic As, DMA and traces of MMA reported Sample solutions were carried in 2% H2SO4 and merged with KBH4. A quartz tube furnace was used. The LOD was 0.2 mg l1 (in Chinese) As was speciated in fish sauce and the starting fish raw material. AB was the major species in the fish, DMA the major species in the sauce Au and Pt intakes in 84 German children, aged 14–83 months, was determined using the duplicate method. Pt levels were slightly higher in subjects who ate exclusively retail products than those who ate a mixture of retail and locally sourced products A rather esoteric study reported the investigation of differences in B intake between pupils in Polish pre-schools and boarding schools. No significant differences were found Samples of wheat, rye, oat, barley, maize and rice were analysed (in German) Changes in the insoluble: soluble Ca ratio and the impact on cheese ripening were investigated A study to estimate the Ca, Mg and P requirements of young Japanese adults was reported Daily dietary intake of Ca and Sr in Pakistan varied from 217 to 713 mg and 0.9 to 5.7 mg. The Ca intakes were inadequate Cd as CdI42 was collected on naphthalene- methyltrioctylammonium chloride adsorbent, eluted with HNO3 and determined by FAAS, with an LOD of 0.6 ng ml1 See Al, ref. 212 212 240 231 226 227 204 191 94 183 192 190 193 190 229 257 185 320 230 243 250 321 322 284 244 196 212 J. Anal. At. Spectrom., 2005, 20, 323–369 357 Table 2 Element Matrix Technique; atomisation; presentation Cd Wine AA;ETA;L Cd Tea AA;ETA;L Cd Vegetables AA;ETA;Sl Cd Honey AA;ETA;L Cd Foods AA;F;Sl Cd Bovine liver, porcine kidney and skimmed milk powder RMs AA;ETA;L Cd Rice flour MS;ICP;LA Cd Rice MS;ICP;ID Co Drinking water AA;ETA;L Co Honey AA;F;FI Co Apple, pear, mandarin orange Beverages, foods RIMS;-;L Co 358 (continued ) AA;ETA;L Cr Alcoholic beverages AA;ETA;L Cu AA;ETA;L Cu Human milk, infant formula Biscuits Cu Foods AA;F;L AE;ICP;L AA;F;L Cu Foods AA;-;L Cu AA;-;L Cu Fe Bovine liver SRM, Tea leaf SRM Rice Milk MS;ICP;L AA;ETA;L Fe Fe Fe Foods Foods Biscuits AA;F;L AA;-;L AA;F;L Hg Milk AF;CV;Sl J. Anal. At. Spectrom., 2005, 20, 323–369 Sample treatment/comments Ref. Samples were microwave digested in HNO3 and Cd and Pb were determined using Zeeman-effect ETAAS with NH4H2PO4 and Mg(NO3)2 as chemical modifiers Perhaps unsurprisingly the Cd and V content of infusions were dependant on tea species and temperature of infusion Ultrasonic slurry sampling ETAAS with a molybdenum tube atomiser was used for the measurement of Cd in Bangladeshi vegetables Honey was diluted in H2O and then H2O2, HNO3 and Triton X-100 added. The performance of Pd þ Mg and alternatively NH4H2PO4 as chemical modifier was compared 50–100 mg of lyophilised material was placed in a test tube, 5 ml HNO3 added, and the mixture sonicated. Following dilution to 10 ml with H2O and then centrifugation, a 400 ml aliquot was taken for ‘‘beam injection flame furnace’’ AAS. The LODs for Cd and Pb were 0.03 and 1.6 mg g1, respectively An unusual digestion procedure (unlikely to appeal to every organisations’ H and S officer) was described in which samples were wrapped in paper, placed in a homemade quartz holder and then inside the quartz vessels of a commercial microwave digestion apparatus. NH4NO3 was added to the paper, the vessel pressurised using O2 to 15 bar and the sample irradiated at 1400 W for 20 s. The sample was combusted in a few seconds and good recoveries reported To construct the calibration line and estimate the LOD, 3 rice flour SRMs were used Cd, Cu and Pb were certified in a candidate RM, for the Institute for Reference Materials and Measurements using ID-ICP-MS. The estimation of uncertainty was discussed in detail Sorption on a conical minicolumn packed with activated carbon, pH 9.5, yielded a 195-fold enrichment factor for a 10 ml sample Co was complexed with 2-(5-bromo-2- pyridylazo)-5diethylaminophenol, retained on an anion exchange resin prior to elution using C2H5OH LODs of o5 pg were achieved 266 323 209 324 208 3 216 269 197 325 219 Samples were digested in a microwave oven using 6 ml HNO3–1 ml H2O2 Cr and Sb were determined in a Brazilian spirit, Cachaca, using ETAAS, with Ru as permanent modifier. Using matrix matched standards the LODs were 2 and 43 pg for Cr and Sb, respectively The effect of pH on enzymatic extraction procedures was investigated 294 Cu and Zn were determined in Croatian samples 326 Cu, Fe and Zn levels were determined in typical Nigerian foods, such as yam pottage and fried plantain. Phytate was also determined, by colorimetry, and phytate : Zn molar ratios calculated Cu, Fe and Zn were determined in high intake Chilean foods following digestion with HClO4–H2SO4–HNO3. Evidence of deficiency, particularly of Zn, was reported Aqueous sample was passed through a C18 membrane disc modified by 1-hydroxy-2-(prop-20 -enyl)-4-(prop-20 -enyloxy)-9,10-anthraquinone. The retained Cu21 was then eluted using HNO3 See Cd, ref. 269 Samples were diluted in 10% v/v CFA-C, obviating the need for a digestion step. Zeeman-effect background correction was employed and Pd was used as chemical modifier during Se measurement See Cu, ref. 246 See Cu, ref. 247 Different digestion procedures were compared for Fe and Zn determination. A microwave procedure using HCl–HNO3, 3 þ 1, at 180 1C and 600 W yielded good results Samples were sonicated for 10 min in a water bath in the presence of 8% (v/v) aqua regia–2% (v/v) antifoam A–1% (m/v) hydroxylamine hydrochloride and then treated with 8 mM KBr and 1.6 mM KBrO3. The LOD was 0.011 ng g1. See also, Various, ref. 207 246 241 211 247 8 269 210 246 247 194 223 Table 2 (continued ) Element Matrix Technique; atomisation; presentation Hg White wines AA;CV;FI Hg Wine AA;ETA;L Hg Rice AF;HG;L Hg Hg Foods Seafood AA;F;L AF;-;GC Hg Fish MS;-;GC Hg Food RMs MS;ICP;ID MS;ICP;HPLC I Salt MS;ICP;ID Mg Diets, faeces, sweat, urine Human milk AA;-;L Mn Mn MS;ICP;SEC AE;ICP;L Ref. Pre-treatment by ozonation allowed a major reduction in reagents and faster analysis times. The LOD was 0.5 mg l1 Hg was preconcentrated from untreated wine by liquid: liquid extraction, with APDC as complexing agent. The LOD was 0.2 mg l1 A microwave digestion method yielded an LOD of 0.005 ng ml1 (in Chinese) See As, ref. 226 2 Hg speciation methods were described. In the first, Hgi and Hg species were ethylated, in the second monoalkylated species were extracted into organic solvent Samples were microwave digested in TMAH, Cu21 added, derivatised with sodium tetrapropylborate and extracted into n-heptane. The LOD for methylmercury was 40 ng g1 As part of a study of contributions to uncertainty the mass fraction of Hg was determined in 1 SRM by ID using MC-SF-ICP-MS whilst the mass fraction of methylmercury in DORM-2 was determined using HPLC-Q-ICP-MS The applicability of the I catalysed reaction (Sandell–Kolthoff) between Ce41 and As31 for the determination of I in salt samples fortified with Fe and I has been studied. The catalytic method data was compared with ICP-MS and no bias found See Ca,284 236 215 327 226 224 127 129 328 284 Mn was speciated in various milk fractions. The species identified included inorganic Mn and citrate complexes, together with uncharacterised species A survey of Canadian retail products suggested that soy and rice beverages contained such high levels that they may pose a risk of adverse neurological effects in infants Samples were finely ground and introduced directly into the furnace by means of solid autosampler system Molybdenum(VI)–thiocyanate complex was collected on a mini-column packed with polyurethane foam. The method yielded an LOD of 0.08 mg l1 The relationship between plasma Mo and dietary intake in humans was investigated. The results demonstrated that, in contrast to most other essential minerals, plasma Mo reflects low and high dietary intakes within 14 days and may provide a useful indicator of dietary intake Results for the WDXRF method compared favourably with those obtained using a standard Mo blue method 123 Mn Rice beverages, soy beverages, infant formula Vitamin tablets AA;ETA;S Mo Water AA;ETA;L Mo Diets, blood plasma MS;ICP;L P WDXRF;-;S AA;-;L See Ca, ref. 284. P was determined spectrophotometrically 284 Pb Genetically modified and non-genetically modified foods Diets, faeces, sweat, urine Tap water AE;ICP;FI 201 Pb Pb Pb Wine Sugar cane spirit Moonshine AA;ETA;L AA;ETA;L AA;ETA;L Pb Water pipes XRF;-;L, SIMS;;L Pb Oil seeds AA;F;L Pb Smoked fish AA;-;- Pb Foods AA;ETA;L A 300-fold preconcentration factor was achieved with cloud point enrichment using polyethyleneglycolmono-p-nonylphenylether. The ‘‘sensitivity’’ was quoted as of 0.077 mg l1 See Al,266 See Cd, ref. 212 A fascinating forensic case was reported. A high incidence of elevated blood Pb in emergency clinic patients in Atlanta, USA, was found to be linked to consumption of moonshine. A survey of 115 moonshine samples seized between 1995–2001 showed 28.7% contained levels above the limit designated potentially hazardous by the FDA An array of techniques was used to characterise lead pipe corrosion products in parts of the Scottish water supply. Secondary neutrals MS showed relationships existed between C, Ca, Fe and P within the bulk of the scale, as well as at the surface A method based on micro-injection and derivative signal processing for Pb and Zn determination was described (in Chinese) A combination of traffic pollution and process contamination resulted in Pb levels of Nigerian fish being 30 times greater than the recommended safety limits Dietary Pb intake was studied in groups of children and one group of adults from the Ruhr and the German island of Amrum. Intakes P AA;-;L Sample treatment/comments 242 214 329 130 222 266 212 235 330 331 233 234 J. Anal. At. Spectrom., 2005, 20, 323–369 359 Table 2 Element 360 (continued ) Matrix Technique; atomisation; presentation Pb Pb Foods Fruit, vegetables, herbs AA;ETA,F;Sl AE;ICP;L Pb Pd Rice Tap water MS;ICP;L AE;ICP;ETV Pd Mussels AA;ETA;L Pd Lettuce XRF;-;SEC Pt Water AA;ETA;FI Pt Pt Pt Rh Rh Sb AE;ICP;ETV AA;ETA;L -;-;AE;ICP;ETV AA;ETA;L AA;ETA;L Sb Tap water Mussels Foods Tap water Mussels Alcoholic beverages Water Se Human milk AF;HG;L Se Milk AF;HG;L Se Drinking water AA;ETA;FI Se AE;ICP;HG Se Infant formula, human milk Yeast AA;F;L Se Se Foods Foods AA;F;L AF;HG;L Se Buckwheat, pumpkin AF;HG;L Se AF;-;HG Se Chicken livers, dogfish liver CRM, proteins Vegetables AF;-;HG Se Infant foods AA;ETA;Sl Se AE;MIP;GC Se Garlic, mustard, yeast Garlic, onion Se Garlic AA;ETA;L MS;ICP;L Se Indian mustard, lupin, sunflower seeds MS;ICP;HPLC MS;ICP;L MS;ICP;HPLC J. Anal. At. Spectrom., 2005, 20, 323–369 Sample treatment/comments were found to be low. Intake studies by the same group were also reported in As, ref. 226 and Au, ref. 243 See Cd, ref. 208 Samples from gardens known to contain Pb-contaminated soil were analysed. This resulted in the perhaps slightly optimistic recommendation that ‘‘urban gardeners should test the lead levels in their soils’’ See Cd, ref. 269 A novel method for determining Pd, Pt and Rh as their gaseous DDC complexes, following ETV at 1100 1C, was described. The LODs were 1.4, 5.4 and 0.8 ng ml1, respectively A microwave digestion-ETAAS method for the determination of Pd, Pt and Rh was described. The LODs were 90, 270 and 13 ng g1, respectively The binding of Pd to high Mr compounds was investigated using gel permeation chromatography and preparative isotachophoresis. At least 5 compounds were present Pt was enriched, by a factor of 41.7, on silica gel functionalised using 1,5-bis(di-2-pyridyl)methylene thiocarbohydrazide. The silica column was placed inside the autosampler arm. Using 60 s preconcentration the LOD was 0.08 ng ml1 See Pd, ref. 138 See Pd, ref. 139 See Au, ref. 243 See Pd, ref. 138 See Pd, ref. 139 See Cr, ref. 211 Sb was determined as part of the ongoing study of Bangladeshi well water contamination. The results did not support the hypothesis that Sb is a significant confounder in the observed relationships between As exposure through drinking water and potential health outcomes Samples were digested using H2SO4–HNO3–H2O2. The LOD was 0.25 ng g1 Samples were treated by sonication with aqua regia and SeIV and TeIV determined without pre-reduction. Total Se and Te were determined after reduction by KBr and SeVI and TeVI obtained by difference SeIV and SeVI were preconcentrated on a microcolumn placed in the autosampler arm, then sequentially eluted using 0.1 M and then 4 M HCl. Ir was used as permanent modifier A study of Spanish retail samples found several formulae did not reach the RDA for the first month of neonate life A method yielding LOD and LOQ of 2.5 mg l1 and 5 mg l1 Se, respectively, was reported See As, ref. 226 The results of a survey of Croatian foods were described. The samples were digested in HClO4–H2SO4–HNO3, 1 þ 1 þ 5 Foliar treatment with SeVI resulted in increases of Se content in pumpkin fruit from 108 to 381 ng g1 and in buckwheat from 15 to 20 ng g1 A single tube method, based on HNO3–H2O2 digestion, yielded an LOD of 0.2 ng g1 in the test solution A very potent digestion mixture comprising H2SO4–HNO3–H2O2– V2O5–HF ultimately yielded an LOD of 0.14 ng g1 Samples were suspended in 0.1% Triton X-100, 0.5 or 5% HNO3 and directly injected into the furnace. The LOD was 0.43 mg l1 Se was speciated using SPME-MIP-AES. Dimethylselenide, diethylselenide and dimethyldiselenide were determined Evidence was presented for the existence of Se ‘‘allins’’ (Se-alk(en)yl-Lcysteine selenoxides) in enriched samples The 2 cited analytical methods were compared and found to offer good agreement. Rh was used as the chemical modifier in the ETAAS method and as internal standard in the ETAAS method Se uptake and distribution was evaluated Ref. 208 258 269 138 139 332 333 138 139 243 138 139 211 261 146 205 198 237 334 226 239 335 147 195 336 203 188 337 338 Table 2 (continued ) Element Matrix Technique; atomisation; presentation Se Yeast MS;ICP;CZE Se Yeast MS;ICP;LA Se Yeast MS;-;ES Se Yeast MS;-;ES MALDI;-;MS Se Yeast Se Yeast-based intervention agents MS;ICP;HPLC MS;ES;HPLC MS;ICP;HPLC Se Mushrooms Se Green onions Se Edible plants MS;ICP;HPLC MS;ES;HPLC MS;ICP;HPLC MS;-;ES MS;ICP;HPLC Se Animal muscle MS;ICP;SEC Se Cod MS;ICP; HPLC,SEC Sn Tin packaging, tomato juice -;-;- Sr Diets Sr Wine AA;-;L AE;ICP;L MS;ICP;L Sr Emmental cheese MS;ICP;L Te U Milk Foods AF;HG;L MS;ICP;L V Zn Tea Milk powder AA;ETA;L AA;F;FI Zn Zn Zn Zn Foods Oil seeds Foods Biscuits Zn Various (15) Biscuits Beverages AA;F;L AA;F;L AA;-;L AA;F;L AE;ICP;L AA;F;L AA;-;L Various (4) Water AA;ETA;L Various (15) Mineral water XRF;SR;L Various (7) Milk, diary products AA;-;L Various (5) Milk AF;HG;Sl Sample treatment/comments Ref. More than 20 species were separated in cold H2O extracts of dietary supplements. Absolute LODs were o250 fg LA was used to study elements in a gel after gel electrophoresis. A DRC was used to reduce interference from the Ar dimer Recent method developments, including characterisation of the water soluble protein fraction by MALDI-TOF-MS and ES quadrupole-TOF tandem MS, were described H2O soluble, cell-wall bound, and membrane-protein Se were sequentially leached from the sample, followed by a further fractionation by high-resolution SEC. SeMet in the H2O insoluble fraction was found to be bound physically to cell wall constituents Simulated gastric and intestinal digests were used to study Se speciation 187 Low Mr species were liberated from the samples by proteolytic hydrolysis followed by separation by ion exchange LC and detection by ICP-MS SeMet was the principal species in selenised shiitake mushrooms Se-cystine, methylselenocysteine, SeMet, g-glutamyl-Semethylselenocysteine and inorganic Se were identified Sprouts of plants (10 families, 28 species including radish) were cultivated in a high Se environment and then speciated. In addition to Se-methylselenocysteine, SeMet, non-metabolized SeIV, g-glutamyl-Se- methylselenocysteine and an unknown Se compound were also detected in several high-selenium sprouts These differences in Se distribution among 7 animal species were discussed in relation to meat quality and nutritional value An octopole reaction system was used to overcome Ar dimer interference. Post-column ID was used to identify and quantify species of which selenomethionine was the major one. 4 extraction procedures were compared An interesting study of gastrointestinal disorders following Sn consumption suggested adverse effects were associated with the form of the Sn rather than the concentration per se See Ca, ref. 244 87 Sr : 86Sr were found to be a suitable marker in a study of the effect of soil composition and vinification process on the ratio The 87S : 86Sr ratios in cheese originating from different regions (alpine, pre-alpine, Bretagne, Finland, Canada, Australia) accorded to local geological properties. The extraction and digestion procedures and interference correction regimes were detailed See Se, ref. 205 The measured values of U were found to vary from 2.3 ng g1 to 11 ng g1 dry weight and posed no health risk See Cd, ref. 323 A FI system for the continuous ultrasound-assisted dissolution of solid soluble samples, yielding a Zn LOD of 0.3 mg g1 was described See Cu, ref. 246 See Pb,331 See Cu, ref. 247 See Cu, ref. 326 See Fe, ref. 194 A survey of 15 soft drinks produced in Pakistan found Al, Cd, Fe, Ni and Pb above WHO recommendations A study to identify preferred permanent modifiers was reported. For Cd and Cr, Rh was selected, whereas Zr was preferred for Al and Pb 37 Brazilian retail samples were measured. Samples were placed on a Perspex carrier, dried with an IR lamp and measured for 200 s Ca, Cu, Fe, K, Mg, Na and Zn were determined in Argentinian samples. The effect of processing, such as skimming, was discussed (in Spanish) Aqua regia was added to samples, 1 ml, which were then treated for 10 min in an ultrasound bath. Pre-reduction was then performed 35 202 339 172 173 186 184 238 340 189 270 244 265 218 205 245 323 179 246 331 247 326 194 263 213 220 253 207 J. Anal. At. Spectrom., 2005, 20, 323–369 361 Table 2 (continued ) Element Various (5) Beer AE;ICP;LC Various (5) Milk, bovine liver, kidney and serum AE;ICP;L Various (63) Wine MS;ICP;L Various (13) Wine MS;ICP;L Various (16) Sparkling wine Various (4) Cow’s milk, human milk, baby foods MS;ICP;L AA;ETA;L AA;HG;L AA;F;L Various (6) Milk Various Human whey, infant formula Various (22) Fish -;-;- Various (4) AA;-;L Various (10) Margarine, shortenings Cereals AA;F;L 342,343 Various (5) Animal feed AA;F;L Various (7) Eggs AA;ETA;L Various (8) Lobster, milk powder and bovine liver RMs Lobster and milk powder RMs AE;MIP;L Various (4) Various (14) Honey Bovine tissues AE;ICP;L AE;ICP;L Various (9) Pet food AE;ICP;L Various (7) Bovine liver AE;ICP;L Various (10) Seville oranges MS;ICP;L Various (6) Mushrooms MS;ICP;SEC Various (10) 362 Matrix Technique; atomisation; presentation AE;ICP;L MS;isotope ratio;L MS;ICP;SEC. AE;MIP;Sl J. Anal. At. Spectrom., 2005, 20, 323–369 Sample treatment/comments with KBr (Se and Te) or KI–ascorbic acid (As and Sb). Bi could be determined with or without pre-reduction. The samples were then slurried with ‘‘antifoam A’’, treated with KBH4 and taken for HGAAS Off-line preconcentration of Cd, Co, Cu, Ni and Zn was achieved using the chelating resin ‘‘Metalfix Chelamine’’ and Dowex 50 W-X4. Difficulties separating the analytes from the resin meant it was necessary to digest the resin, rather than perform an elution step Slight differences were observed between the industrial and nonindustrial regions of Turkey, but generally industrial activities and seasonal changes had no significant effect on selected element concentrations on cows and their milk (Cr, Cu, Fe, Mn, Zn) German wines were microwave digested and In used as internal standard in semiquant. mode. The study paid particular regard to the influence of ingredients such as bentonite and yeast on element composition The same research group as in ref. 264 analysed 127 samples from 4 wine regions of Germany, using SF-ICP-MS and a simple 1 : 20 dilution of the sample. Classification based on decision tree was more accurate than one using quadratic discriminant analysis Pattern recognition techniques allowed Brut champagne and Brut cava to be distinguished with 100% accuracy 3 sample digestion procedures using dry and wet ashing and microwave oven were compared. Microwave methods offered the best performance, except for the measurement of Fe in biscuits and rice flour (Cu, Fe, Mn, Zn) The geographical origin of 20 Italian milk samples was classified with 100% accuracy using multivariate chemometric methods (Al, Ba, Cu, Fe, Mn, Zn) The ICP-MS was fitted with an octopole reaction cell and speciation of premature whey and premature infant formula conducted for essential and toxic elements. Important differences in essential elements, e.g., Cu, Fe and Zn were noted The partial results were reported of a very comprehensive survey of contaminants in Norwegian fish, of planned duration 1994–2010 The use of ultrasonic assisted acid extraction reduced the conventional acid extraction time from 180 to 10 min A pair of papers reported elemental levels in Pakistanian wheat varieties (ref. 342) and maize hybrids (ref. 343) A dynamic and automated ultrasound-assisted extractor was used for Ca, Cu, Fe, Mg and Zn determination The concentration of Cd and Pb in Nigerian eggs was higher than reported levels from other parts of the world Samples were mineralised using TMAH in a microwave oven Slurries were prepared in 10% HNO3 containing 0.01% Triton X-100 and fed directly into the microwave cavity-torch assembly (Ca, Cd, Cu, K, Mg, Mn, Na, P, Sr, Zn) Cr, Fe, Mn and Ni were determined The interactions between toxic elements (As, Cd, Hg and Pb) and essential elements (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) were investigated Samples were prepared by microwave digestion. Due to the heterogeneity of pet food premixes it was necessary to use large sample sizes to avoid poor repeatability (Ca, Cr, Cu, Fe, Mg, Mn, Mo, Se, Zn) Samples were partially digested using the vapour from HNO3–H2SO4 heated to 120 1C in a microwave oven (Al, Ca, Cu, Fe, Mg, Mn, and Zn) Al, Ba, Cd, Cr, Cu, Mn, Ni, Pb, V and Zn were determined in samples from Seville and Palermo 0.05 M NaOH, 0.05 M HCl, and H2O at 60 1C were evaluated for obtaining Mr distribution patterns for Ag, As, Cd, Hg, Pb and Sn among different fractions Ref. 199 252 264 274 275 341 277 251 260 181 180 268 14 15 344 347 225 4 345 346 Table 2 (continued ) Element Matrix Technique; atomisation; presentation Various (5) Rice flour MS;ICP;ETV Various (68) MS;ICP;L Various (8) Animal and fish tissues Peas Various (36) Barley MS;ICP;L MS;IR;L Various (15) Yeast MS;ICP;LA Various (6) Onion XRF;-;L Various Beverages, foods -;-;- Various (5) Food packaging plastics MS;ICP;L MS;ICP;L MS;ICP;SEC Sample treatment/comments Ref. Ultrasonic slurry sampling-ETV-DRC-ICP-MS was used to determine Cd, Cr, Cu, Hg and Pb at LODs of 0.4, 0.44, 1.7, 0.53 and 0.60 ng g1, respectively. Ascorbic acid was used as chemical modifier SF-ICP-MS, following microwave-assisted digestion using HNO3, was applied to the analysis of muscle, liver, kidney, lung and brain The effect of cooking on concentrations of Co, Cu, Fe, Mn, Mo, Ni, P and Zn was studied. Soluble high molecular weight species, present in the original pea, were completely removed by boiling The study examined the possibility of generating a unique elemental fingerprint of individual barley genotypes irrespective of soils fertility and agricultural practice In addition to the analysis of Se described in ref. 35, the LOD, range and linearity of other elements were calculated Analyte elements were extracted by ultrasonic agitation in acid. The results were compared with dry and wet ashing. Differences in element concentrations were found between 2 cultivars (Ca, Cu, Fe, K, Mn, Zn) A review of developments in the atomic spectrometric determination of beverages and foods Samples were digested in HNO3–H2O2 using a high pressure microwave system (As, Cd, Cr, Pb, Sb) 217 region of viniculture. This approach has been applied to Swiss,273 German274 and other wines.275,276 More recently it has emerged that Sr isotopic ratios may serve this purpose and some preliminary work has been reported for wines from the Portuguese district of Douro265 and for Emmental-type cheeses from Australia, Canada, Finland and France.218 Other workers have applied preliminary measurements of trace elements to identify the origin of cow milk in Italy277 and Danish barley.256 Analyses of foods and beverages are set down in Table 2. 4 Conclusions Over the years, Atomic Spectrometry Updates has been chronicling advances in the application of ICP-MS to the analysis of clinical and biological samples, foods and beverages. This year, it is evident we are moving into a new phase. Previous Updates have commented on the few papers appearing that used dynamic reaction cells or octopole cells with quadrupole ICP-mass spectrometers in the clinical field. This year, there are many more and it is clear that these spectrometers are now standard in many laboratories. Other laboratories have standardised on sector-field ICP-mass spectrometers, once just a research curiosity. The reason for this advance is clear. Isobaric interferences have been a difficult problem to solve for researchers trying to apply ICP-MS to the determination of certain elements in the clinical field. Both sector-field ICPMS and dynamic reaction or octopole cells in quadrupole ICPMS drastically reduce these interferences, leading to improved accuracy. As Sturup commented,22 these and other advances have resulted in ICP-MS replacing the more complicated TIMS technique for isotope studies in nutritional research. An interesting application of the DRC was to determine P and S in cell culture digests as PO1 and SO1 through the addition of O2 to the reaction cell.133 Aleixo et al.208 showed that there are still opportunities for innovation involving FAAS with the beam injection system permitting useful improvements in the LODs for Cd and Pb in slurried powdered samples. In recent years, the extension of in vivo XRF determination to elements other than Pb has been noted. In this review, the feasability of measurement of Ag and As in skin has been assessed49,50 and there has been some interesting development 31 272 256 35 178 1 271 in the potentially useful assesment of prostate cancer by in vivo determination of Zn in the prostate.51,52 The pollution of groundwater in West Bengal with As has been a disaster to the people living in the affected areas. Recent studies have shown, through hair and nail analysis, that nail is a good biomarker for As75 and has indicated that other elements, such as Mn, Ni and Pb, may have been involved. A suggestion that the clinical problems were related to Sb exposure has been disproved, as levels of Sb in the water were insignificant.261 Speciation of the As in hair and nails indicates that AsIII is the main species involved.75 Abnormally high As concentrations found in fossil skeletons of dinosaur species led Zhou et al.98 to suggest that As toxicity could have contributed to the extinction of dinosaurs in the Chinese Province of Sichuan. Contrast this to the current interest in the use of As to treat carcinomas.96,97 Speciation of As and Se remains a topical subject, increasing our knowledge but also showing the increased complexity of the situation. Ten species have been found in human urine after ingestion of selenised yeast,149,150 but only three have been identified so far. The bioavailability of SeMet was shown to be rather more complex than originally appeared when a study using selenised yeast in cancer prevention programmes demonstrated that SeMet in this form causes greater increases in serum Se than does simple synthetic SeMet. Arsenobetaine, the major form of As in fish, was once thought to stable and nontoxic. Kato et al.230 showed that, once fish is made into a sauce, most of the AsB has been converted to MMA. This study confirms earlier studies indicating that AsB can be broken down to more toxic As species. Meanwhile, Rattaanachongkiat et al.193 found that where there is sufficient inorganic As in the water not all will be metabolised to AB and the fish can then present a significant health risk. The story of Cd contamination of rice in Japan, leading to Itai-Itai disease, is very well known. Now, more than 30 years later, it is evident that remediation work has been successful but still the concentrations of Cd in Japanese rice are greater than elsewhere and the costs in terms of human tragedy are incalculable. Should there ever be contamination of food from the packaging, further disasters may emerge. What might be thought to be a potential problem, with migration of Sn from cans, appears to be of little concern as no adverse effects could be demonstrated by the Sn species thus formed.270 J. Anal. At. Spectrom., 2005, 20, 323–369 363 (continued ) Appendix Abbreviations used in this update Abbreviations used in this update AA AAS AB AC AES AFS AMS APDC BCR CE CRM CSF CSV CV-AAS CV-AFS CZE DDC DIN DMA DMF DNA DRC DTPA EDTA EDXRF EI-MS EPMA EPR ES-MS ES-Q-TOFMS ETA ETAAS ETV FAAS FAES FAO FDA FI GC-MS HGAAS HGAFS HPLC HR-ICP-MS IAEA IBMK ICP ICP-MS ID ISO LA-ICP-MS LC-ICP-MS LOD LOQ m0 MALDI MC MIP MMA Mr MRI MS NAA NCT NIES 364 Atomic absorption Atomic absorption spectrometry Arsenobetaine Arsenocholine Atomic emission spectrometry Atomic fluorescence spectrometry Accelerator mass spectrometry Ammonium pyrrolidinedithiocarbamate Bureau Communité de Référence Capillary electrophoresis Certified reference material Cerebrospinal fluid Cathodic stripping voltametry Cold vapour AAS Cold vapour AFS Capillary zone electrophoresis Diethyldithiocarbamate Direct injection nebuliser Dimethylarsinic acid NN-dimethylformamide Deoxyribose nucleic acid Dynamic reaction cell Diethylenetriaminepentaacetic acid Ethylenediaminetetraacetic acid Energy dispersive XRF Electron impact-MS Electron probe microanalysis Electron paramagnetic resonance Electrospray MS Electrospray-quadrupole TOF-MS Electrothermal atomisation Electrothermal atomisation AAS Electrothermal vaporisation Flame AAS Flame AES Food and Agriculture Organisation Food and Drug Adminstration Flow injection Gas chromatography-MS Hydride generation AAS Hydride generation AFS High performance liquid chromatography High resolution ICP-MS International Atomic Energy Authority Isobutyl methyl ketone Inductively coupled plasma Inductively coupled plasma-mass spectrometry Isotope dilution International Standards Organisation Laser ablation ICP-MS Liquid chromatography ICP-MS Limit of detection Limit of quantitation Characteristic mass Matrix-assisted laser desorption ionization Multiple collector Microwave induced plasma Monomethylarsonic acid Relative molecular mass Magnetic resonance imaging Mass spectrometry Neutron activation analysis Neutron capture therapy National Institute for Environmental Studies J. Anal. At. Spectrom., 2005, 20, 323–369 NIST NMR OES PAGE PIXE PTFE RDA RIMS RM RSD SDS SEC SeCys SeMet SF-ICP-MS SIMS SPME SRM SRXRF TCA THGA TIMS TMA TMAH TMAO TMI TOF-ICP-MS TXRF WDXRF WHO XANES XRF National Institute of Standards Technology Nuclear magnetic resonance Optical emission spectrometry Polyacrylamide gel electrophoresis Particle-induced X-ray emission Poly(tetrafluorethylene) Recommended dietary allowance Resonance ionisation-MS Reference material Relative standard deviation Sodium dodecylsulfate Size exclusion chromatography Selenocysteine Selenomethionine Sector field ICP-MS Secondary ion MS Solid phase microextraction Standard reference material Synchrotron radiation XRF Trichloroacetic acid Transversely heated graphite atomiser Thermal ionisation MS Trimethylarsine Tetramethylammonium hydroxide Trimethylarsine oxide Tetramethylarsonium ion Time-of-flight ICP-MS Total reflection XRF Wavelength dispersive XRF World Health Organisation X-ray absorption near-edge structure X-ray fluorescence References 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 A. 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