Evaluation of Sample Preparation Methods for Semi-Quantitative, Ultra-High Throughput Urine Forensic Screening Using an LDTD HRAM MS Technique Marta Kozak, Kristine Van Natta Thermo Fisher Scientific, San Jose, CA Overview Purpose: Evaluation of sample preparation procedures for a laser diode thermal desorption (LDTD) ion source coupled to a high-resolution, accurate-mass (HRAM) mass spectrometer for ultrafast quantitative screening of drugs of abuse in urine, for forensic toxicology. Methods: Samples were prepared by either liquid-liquid extraction (LLE) or urine dilution and then plated onto a 96--well LazWell™ plate, and introduced into the HRAM MS using a Phytronix™ LDTD™ ion source. Results: With adequate sample preparation, LDTD can achieve the limits of detection required for forensic screening of urine samples. Introduction The new technique – laser diode thermal desorption (LDTD), high-resolution accuratemass (HRAM) mass spectrometry – allows for rapid screening of compounds in biological matricies. Because of the short 10 s analysis time of LDTD and high selectivity provided by HRAM MS, the method meets ultra-high throughput requirements of forensic toxicology labs. Since there is no chromatographic separation between matrix components and analytes, the sample preparation method has to be carefully selected to minimize matrix effects and to obtain the required limit of quantitation (LOQ). Here we investigated two sample preparation methods – LLE and multiple dilutions – to evaluate matrix effects and LOQ for eight representative compounds, including three each benzodiazepines (alprazolam, lorazepam, and nordiazepam) and amphetamines (amphetamine, methamphetamine, and MDMA) and two opioids (fentanyl and oxycodone), in urine samples. LDTD The LDTD carrier gas flow was from 0 to 65% in six seconds w (Figure 1). The total acquisition shown in Figure 2. Mass Spectrometry The Q Exactive mass spectrom parent ions were selected with fragmentation data was collect of data obtained from this scan was 1 m/z and fragmentation s were selected for quantitation a reconstructed with mass accur settings are listed in Table 1. Ta FIGURE 2. Schematic showin Methods Sample Preparation Samples were prepared by enzymatic hydrolysis followed by liquid-liquid extraction or urine dilution at 1x, 4x, 10x, 20x, 40x, or 80x. Calibration standards (1–500 ng/mL) were prepared in negative urine. Briefly, 0.2 mL of urine (spiked calibrator) was spiked with internal standard and incubated with 0.1••mL of 10,000 U/mL beta-glucuronidase enzyme in pH 5.5 buffer for 60 min at 60 °C. For LLE, a 0.1 mL aliquot of the resulting mixture was basified with 0.05 mL of 1 M sodium carbonate and extracted with 0.3 mL of ethylacetate/hexane (1:1). For urine dilution, the incubation mixture was diluted with water by the factors given above. A 96-well LazWell plate was prepared by depositing 5 µL of a 20 µg/mL EDTA solution in methanol/water/ammonium hydroxide (75:20:5) onto the plate and drying. Then 5 µL of either the LLE organic supernatant or the diluted urine was aliquoted onto the same plate and again dried. Samples were introduced into the Thermo Scientific™ Q Exactive™ hybrid quadrupole-Orbitrap™ mass spectrometer by thermal desorption from the plate using a Phytronix LDTD source. FIGURE 1. LDTD method FIGURE 3. Targeted-MS2 data Parent ion was selected by q cell. Full high resolution-acc from the Orbitrap mass analy quantification and confirmati with m/z accuracy of 5 ppm. Relative Abundance Relative Abundance Relative Abundance Relative Abundance C:\TraceFinderData\...\Data\500-LLE RT:0.00 - 0.17 100 80 60 40 20 0 100 80 60 40 Fra 2 20 0 100 80 60 40 Fra 2 20 0 100 80 60 40 Re 20 0 0.00 2 Evaluation of Sample Preparation Methods for Semi-Quantitative, Ultra-High Throughput Urine Forensic Screening Using an LDTD HRAM MS Technique 0.05 0.10 Time (min) 0.15 for a laser diode thermal on, accurate-mass (HRAM) f drugs of abuse in urine, for extraction (LLE) or urine and introduced into the HRAM achieve the limits of detection DTD), high-resolution accurateeening of compounds in time of LDTD and high ra-high throughput no chromatographic separation reparation method has to be n the required limit of eparation methods – LLE and or eight representative azolam, lorazepam, and amphetamine, and MDMA) and LDTD Data Analysis The LDTD carrier gas flow was set at 3 L/min, and the laser pattern was an energy ramp from 0 to 65% in six seconds with a short hold followed by an immediate return to zero (Figure 1). The total acquisition time was ten seconds. Details of the LDTD process are shown in Figure 2. Data were acquired and processed w version 3.2. Mass Spectrometry The Q Exactive mass spectrometer was operated in Targeted-MS2 mode. In this mode, parent ions were selected with the quadrupole filter and then high-resolution fragmentation data was collected in the Orbitrap mass analyzer. An example of the type of data obtained from this scan mode is shown in Figure 3. Parent ion isolation window was 1 m/z and fragmentation spectra were collected at 17,500 resolution. Two fragments were selected for quantitation and confirmation and related chronograms were reconstructed with mass accuracy of 5 ppm. Other Q Exactive MS source parameter settings are listed in Table 1. Targeted-SRM parameter are shown in Figure 4. FIGURE 2. Schematic showing LDTD process Calibration ranges, LODs, and LOQs accuracy; back-calculated concentrat Matrix effects were determined by co in multiple lots of urine to the respons without beta-glucuronidase enzyme. TABLE 1. Source parameters for Q Exactive MS Parameter Value Sheath Gas 0 Aux Gas 0 Sweep Gas 0 Discharge Current (µA) 3 Capillary Temp (°C) 300 RF-Lens Level 50 Vaporizer Temp (°C) 0 (off) Results ed by liquid-liquid extraction or n standards (1–500 ng/mL) (spiked calibrator) was spiked 00 U/mL beta-glucuronidase 0.1 mL aliquot of the resulting nate and extracted with 0.3 mL bation mixture was diluted with e was prepared by depositing monium hydroxide (75:20:5) rganic supernatant or the ain dried. Samples were brid quadrupole-Orbitrap™ e using a Phytronix LDTD Limits of Quantitation For limits of quantitation, results were opioids gave their lowest limits of qua Amphetamines responded best with 4 Table 2. Figure 5 shows representativ and oxycodone. Figure 6 shows chro Matrix Effects FIGURE 3. Targeted-MS2 data obtained from Q Exactive MS for alprazolam. Parent ion was selected by quadrupole mass filter and then fragmented in HCD cell. Full high resolution-accurate mass fragmentation spectra were obtained from the Orbitrap mass analyzer. Appropriate fragments were then selected for quantification and confirmation. Fragment chronograms were reconstructed with m/z accuracy of 5 ppm. Based on the data obtained earlier fo samples processed by LLE and at 1x the LOQs, class dependent. Benzodi fewest matrix effects with LLE proces sample preparation scheme was orig also responded best with LLE. Oxyco Amphetamines showed matrix enhan dilution. The wide range of matrix effe for analysis by LDTD. Results are sh Relative Abundance Relative Abundance Relative Abundance Relative Abundance C:\TraceFinderData\...\Data\500-LLE 500-LLE #45 RT:0.06 AV:1 NL:3.50E6 NL: 1.78E7 F: FTMS + c APCI corona Full ms2 [email protected] [50.00-335.00] 281.0713 TIC F: FTMS + c APCI 100 corona Full ms2 [email protected] 95 [50.00-335.00] MS 500-LLE 90 RT:0.00 - 0.17 100 quantifier 80 60 40 TIC 20 60 40 Fragment m/z 281.0712 NL: 8.24E5 20 0 100 55 m/z= 274.1199-274.122750 F: FTMS + c APCI corona 45 Full ms2 [email protected] [50.00-335.00] MS 40 500-LLE 35 80 60 40 Fragment m/z 274.1213 NL: 1.14E6 20 0 100 60 40 20 0.05 0.10 Time (min) Remaining Parent 0.15 parent 309.0901 30 25 m/z= 309.0886-309.0916 F: FTMS + c APCI corona 20 Full ms2 [email protected] 15 [50.00-335.00] MS 500-LLE 10 80 0 0.00 Relative Abundance 80 LLE 85 80 NL: 3.50E6 m/z= 281.0698-281.072675 F: FTMS + c APCI corona Full ms2 70 [email protected] [50.00-335.00] MS 65 500-LLE 60 0 100 TABLE 2. Limits of quantitation in 5 0 qualifier 274.1213 241.0527 165.0216 205.0755 138.0106 191.0880 224.0262 251.0371 149.0600172.0870 150 200 m/z 250 1x Amphetamine ND 10 MDMA 200 100 Methamphetamine ND NA Alprazolam 2 ND Lorazepam 5 500 Nordiazepam 1 0 Fentanyl 5 5 Oxycodone 5 500 294.1029 300 Thermo Scientific Poster Note • PN-64128-ASMS-EN-0614S 3 Data Analysis he laser pattern was an energy ramp wed by an immediate return to zero ds. Details of the LDTD process are Targeted-MS2 mode. In this mode, and then high-resolution ss analyzer. An example of the type gure 3. Parent ion isolation window at 17,500 resolution. Two fragments related chronograms were Q Exactive MS source parameter ter are shown in Figure 4. Calibration ranges, LODs, and LOQs were evaluated based on concentration accuracy; back-calculated concentrations had to be within 30%. Matrix effects were determined by comparing the peak response of samples prepared in multiple lots of urine to the response of samples prepared in water both with and without beta-glucuronidase enzyme. TABLE 1. Source parameters for Q Exactive MS Parameter Value Sheath Gas 0 Aux Gas 0 Sweep Gas 0 Discharge Current (µA) 3 Capillary Temp (°C) 300 RF-Lens Level 50 Vaporizer Temp (°C) FIGURE 4. Targeted-MS2 scan settings with inclusion list 0 (off) Results Limits of Quantitation For limits of quantitation, results were compound class specific. Benzodiazepines and opioids gave their lowest limits of quantitation with LLE sample processing. Amphetamines responded best with 4x urine dilution. These results are summarized in Table 2. Figure 5 shows representative calibration curves for MDMA, nordiazepam, and oxycodone. Figure 6 shows chronograms for the same compounds at their LOQs. FIGURE 6. Representative chro showing quantifier and confirm Matrix Effects xactive MS for alprazolam. er and then fragmented in HCD tation spectra were obtained gments were then selected for nograms were reconstructed 0.06 AV:1 NL:3.50E6 PCI corona Full ms2 [email protected] [50.00-335.00] 281.0713 quantifier parent 309.0901 qualifier 274.1213 241.0527 165.0216 205.0755 106 191.0880 224.0262 251.0371 49.0600172.0870 150 Data were acquired and processed with Thermo Scientific™ TraceFinder™ software version 3.2. FIGURE 5. Representative cali oxycodone obtained using LD 200 m/z 250 Based on the data obtained earlier for LOQs, matrix effects were determined in samples processed by LLE and at 1x, 4x, and 40x dilution. Matrix effects were, as for the LOQs, class dependent. Benzodiazepines showed the best signal response and fewest matrix effects with LLE processing. This is to be expected since this particular sample preparation scheme was originally optimized for benzodiazepines. Fentanyl also responded best with LLE. Oxycodone showed the fewest effects at 4x dilution. Amphetamines showed matrix enhancement with LLE and the fewest effects at 40x dilution. The wide range of matrix effects indicate that sample processing will be critical for analysis by LDTD. Results are show in Figures 7 and 8. TABLE 2. Limits of quantitation in ng/mL for compounds tested LLE 1x 4x 10x 20x 40x Amphetamine ND 10 5 50 100 50 50 MDMA 200 100 1 1 20 50 50 Methamphetamine ND NA 5 10 50 100 200 2 ND 10 5 20 1 5 Lorazepam 5 500 100 200 50 20 50 Nordiazepam 1 0 200 5 20 2 5 Fentanyl 5 5 10 NA ND NA NA Oxycodone 5 500 5 5 20 20 10 Alprazolam 80x 294.1029 300 4 Evaluation of Sample Preparation Methods for Semi-Quantitative, Ultra-High Throughput Urine Forensic Screening Using an LDTD HRAM MS Technique ntific™ TraceFinder™ software FIGURE 5. Representative calibration curves for MDMA, nordiazepam, and oxycodone obtained using LDTD-MS based on concentration within 30%. FIGURE 7. Matrix effects. Peak sample preparation technique water with beta-glucuronidase 242% 200% 180% 160% 140% 120% 100% 80% 60% 40% 20% 0% k response of samples prepared epared in water both with and RE 4. Targeted-MS2 scan settings nclusion list 347% 312% 200% 180% 160% 140% 120% 100% 80% 60% 40% 20% 0% FIGURE 8. Detail of matrix effe processing schemes. Matrix e There was no significant diffe 40x dilution and with LLE proc areas for nordiazepam. effects were determined in ution. Matrix effects were, as for d the best signal response and be expected since this particular for benzodiazepines. Fentanyl e fewest effects at 4x dilution. E and the fewest effects at 40x sample processing will be critical and 8. pounds tested 0x 20x 40x 80x 50 100 50 50 100000000 FIGURE 6. Representative chronograms for MDMA, nordiazepam, and oxycodone showing quantifier and confirming ions Water w/ Water enzyme enzy 10000000 Peak Area s specific. Benzodiazepines and E sample processing. These results are summarized in rves for MDMA, nordiazepam, same compounds at their LOQs. urine 1000000 100000 10000 1x Conclusion Sample preparation is crit For best results, compoun preparation can be suitab With adequate sample pre required for forensic scree 1 20 50 50 10 50 100 200 5 20 1 5 200 50 20 50 We would like to thank Dr. Pierre Technologies Inc., for his assista 5 20 2 5 NA ND NA NA For forensic use only. 5 20 20 10 Acknowledgeme Phytronix, LDTD, and LazWell are a trade property of Thermo Fisher Scientific and it This information is not intended to encour intellectual property rights of others. Thermo Scientific Poster Note • PN-64128-ASMS-EN-0614S 5 MDMA, nordiazepam, and FIGURE 7. Matrix effects. Peak response for compounds tested using different sample preparation techniques. Graphs are normalized to samples prepared in water with beta-glucuronidase enzyme. 605% 242% 200% 180% 160% 140% 120% 100% 80% 60% 40% 20% 0% 601% 347% LLE Lots H2O+ß H2O-ß 312% 200% 180% 160% 140% 120% 100% 80% 60% 40% 20% 0% 4x Lots H2O+ß H2O-ß 431% 769% 251% 478% 479% 455% 200% 180% 160% 140% 120% 100% 80% 60% 40% 20% 0% 200% 180% 160% 140% 120% 100% 80% 60% 40% 20% 0% 1x Lots H2O+ß H2O-ß 512% 40x Lots H2O+ß H2O-ß FIGURE 8. Detail of matrix effects for nordiazepam under different sample processing schemes. Matrix effects were greatest at 1x and then 4x dilution. There was no significant difference between matrix and non-matrix samples at 40x dilution and with LLE processing; however, LLE gave the highest peak areas for nordiazepam. 100000000 MA, nordiazepam, and oxycodone urine Water w/ Water w/o enzyme enzyme urine urine 10000000 Peak Area urine W+ß W-ß W+ß W-ß W+ß W-ß 1000000 100000 10000 1x 4x 40x Sample Processing Scheme LLE Conclusion Sample preparation is critical for successful analysis by LDTD. For best results, compounds should be analyzed in classes, so sample preparation can be suitably tailored. With adequate sample preparation, LDTD can achieve the limits of detection required for forensic screening of urine samples. Acknowledgements We would like to thank Dr. Pierre Picard, Vice President of R&D at Phytronix Technologies Inc., for his assistance in setting up the LDTD source. For forensic use only. Phytronix, LDTD, and LazWell are a trademarks of Phytronix Technologies, Inc. All other trademarks are the property of Thermo Fisher Scientific and its subsidiaries. This information is not intended to encourage use of these products in any manners that might infringe the intellectual property rights of others. PO64128-EN 0614S 6 Evaluation of Sample Preparation Methods for Semi-Quantitative, Ultra-High Throughput Urine Forensic Screening Using an LDTD HRAM MS Technique For forensic toxicology use only. www.thermoscientific.com ©2014 Thermo Fisher Scientific Inc. All rights reserved. ISO is a trademark of the International Standards Organization. Phytronix, LDTD, and LazWell are a trademarks of Phytronix Technologies, Inc. All other trademarks are the property of Thermo Fisher Scientific and its subsidiaries. This information is presented as an example of the capabilities of Thermo Fisher Scientific products. It is not intended to encourage use of these products in any manners that might infringe the intellectual property rights of others. Specifications, terms and pricing are subject to change. Not all products are available in all countries. Please consult your local sales representative for details. Africa +43 1 333 50 34 0 Australia +61 3 9757 4300 Austria +43 810 282 206 Belgium +32 53 73 42 41 Canada +1 800 530 8447 China 800 810 5118 (free call domestic) 400 650 5118 Denmark +45 70 23 62 60 Europe-Other +43 1 333 50 34 0 Finland +358 9 3291 0200 France +33 1 60 92 48 00 Germany +49 6103 408 1014 India +91 22 6742 9494 Italy +39 02 950 591 Japan +81 45 453 9100 Latin America +1 561 688 8700 Middle East +43 1 333 50 34 0 Netherlands +31 76 579 55 55 New Zealand +64 9 980 6700 Norway +46 8 556 468 00 Russia/CIS +43 1 333 50 34 0 Thermo Fisher Scientific, San Jose, CA USA is ISO 13485 Certified. Singapore +65 6289 1190 Spain +34 914 845 965 Sweden +46 8 556 468 00 Switzerland +41 61 716 77 00 UK +44 1442 233555 USA +1 800 532 4752 PN-64128-EN-0614S
© Copyright 2024