IC Column Selection The world leader in serving science 1 Thermo Scientific Dionex IonPac Columns • Anion-Exchange Columns • Hydroxide Selective • Carbonate Selective • Cation-Exchange Columns • Ion-Exclusion Columns • Concentrator and Trap Columns 2 When to Use Hydroxide-Selective Columns • Trace analyte determinations • Gradient resolution of complex samples • Large loop injection analyses • Easier integration of early-eluting compounds • Combine with Eluent Generation for best overall performance • Routine anion analysis (Dionex IonPac™ AS18 and Dionex IonPac AS18-4µm) 3 When to Choose High Capacity Choose High Capacity • When analyzing organic acids and inorganic anions in high ionic strength matrices • For best resolution of weakly retained anions (such as monovalent organic acids) • For complex matrices where increased column ruggedness is desirable 4 Choose Lower Capacity • For analysis of simple samples, where analytes are present at similar concentrations • For fast profiling of inorganic anions and organic acids in wellcharacterized samples Hydroxide-Selective Dionex IonPac Anion-Exchange Columns 5 Column Formats Primary Application Dionex IonPac AS11-HC-4µm 0.4 × 250 mm High resolution, high capacity column for the determination of organic acids and inorganic anions in uncharacterized samples. Dionex IonPac AS18-4µm 0.4 × 150 mm Recommended hydroxide selective column for fast high resolution separations of inorganic anions in diverse matrices. Dionex IonPac AS26 0.4 × 250 mm 2 × 250 mm 4 × 250 mm High capacity column for the separation of haloacetic acids (HAAs) in drinking water. The capillary format is used in the 2nd dimension of the 2D-IC method for HAAs. Dionex IonPac AS25 0.4 × 250 mm 2 × 250 mm 4 × 250 mm High capacity columns for the separation of multivalent anions and polarizable anions (iodide and perchlorate) including sulfur species (sulfite, sulfate, thiosulfate and thiocyanate) in complex anions. Dionex IonPac AS24A 0.4 × 250 mm 2 × 250 mm 4 × 250 mm High capacity column for the separations of haloacetic anions as well as a variety of environmental anions. The standard bore column is used in the 1st dimension of the 2D-IC method for HAAs. Hydroxide-Selective Dionex IonPac Anion-Exchange Columns Column Formats Primary Application 2 × 250 mm Recommended hydroxide selective column for haloacetic acids prior to MS or MS/MS detection. 2D method for trace bromate. Dionex IonPac AS21 2 × 250 mm Recommended hydroxide selective column for trace perchlorate prior to MS or MS/MS detection. EPA Method 331.0 Dionex IonPac AS20 0.4 × 250 mm 2 × 250 mm 4 × 250 mm Recommended hydroxide selective column for trace perchlorate prior to suppressed conductivity detection. EPA Method 314.1. Hydrophobic and polyvalent anions. Dionex IonPac AS19 0.4 × 250 mm 2 × 250 mm 4 × 250 mm Recommended hydroxide selective column for inorganic anions and oxyhalides. Trace bromate in drinking water. Dionex IonPac AS18 0.4 × 250 mm 2 × 250 mm 4 × 250 mm High capacity hydroxide-selective column for the analysis of common inorganic anions. Dionex IonPac AS24 6 Hydroxide-Selective Dionex IonPac Anion-Exchange Columns Column Formats Dionex IonPac AS18-Fast 0.4 × 150 mm 2 × 150 mm 4 × 150 mm Hydroxide-selective column for fast analysis of common inorganic anions. Dionex IonPac AS17-C 2 × 250 mm 4 × 250 mm Low capacity for fast analysis of common inorganic anions using gradient elution. Dionex IonPac AS16 2 × 250 mm 4 × 250 mm High capacity for hydrophobic anions including iodide, thiocyanate, thiosulfate, and perchlorate. Polyvalent anions including: polyphosphates and polycarboxylates. Trace perchlorate. EPA Method 314.1 & 332.0 Dionex IonPac AS15 0.4 × 250 mm 2 × 250 mm 4 × 250 mm High capacity for trace analysis of inorganic anions and low molecular weight organic acids in high purity water matrices. 3 × 150 mm Fast run, high capacity for trace analysis of inorganic anions and low molecular weight organic acids in high purity water matrices. Dionex IonPac AS15-5µm 7 Primary Application Hydroxide-Selective Dionex IonPac Anion-Exchange Columns 8 Column Formats Primary Application Dionex IonPac AS11-HC 0.4 × 250 mm 2 × 250 mm 4 × 250 mm High capacity for the determination of organic acids and inorganic anions in uncharacterized samples. Dionex IonPac AS11 2 × 250 mm 4 × 250 mm Low capacity for fast profiling of organic acids and inorganic anions in well-characterized samples. Dionex IonPac AS10 2 × 250 mm 4 × 250 mm High capacity for the analysis of inorganic anions and organic acids in high nitrate samples. Dionex IonPac Cryptand A1 3 × 150 mm Polarizable anions, polyvalent anions including polyphosphates and polysulfonates. Dionex IonPac Fast Anion IIIA 3 × 250 mm Recommended hydroxide selective column for phosphoric and citric acids in cola soft drinks. Carbonate-Based Dionex IonPac Anion-Exchange Columns 9 Column Formats Primary Application Dionex IonPac AS23 2 × 250 mm 4 × 250 mm Recommended carbonate-based column for inorganic anions and oxyhalides. Trace bromate in drinking water. Dionex IonPac AS22 2 × 250 mm 4 × 250 mm Recommended carbonate-based column for fast analysis of common inorganic anions. Dionex IonPac AS14A- 5µm 3 × 150 mm Moderate column for fast analysis of common inorganic anions. Dionex IonPac AS14A 4 × 250 mm Moderate capacity for analysis of common inorganic anions. Dionex IonPac AS14 2 × 250 mm 4 × 250 mm Moderate capacity for fast analysis of common inorganic anions. Carbonate-Based Dionex IonPac Anion-Exchange Columns 10 Column Formats Primary Application Dionex IonPac AS12A 2 × 200 mm 4 × 200 mm Moderate capacity for analysis of inorganic anions and oxyhalides. Trace chloride and sulfate in high carbonate matrices. Dionex IonPac AS9-HC 2 × 250 mm 4 × 250 mm High capacity column for inorganic anions and oxyhalides. Trace bromate in drinking water. Dionex IonPac AS9-SC 4 × 250 mm Low capacity for fast analysis of inorganic anions and oxyhalides. Specified column in EPA Method 300.0 (B). Dionex IonPac AS4A-SC 2 × 250 mm 4 × 250 mm Low capacity for fast analysis of common inorganic anions. Specified column in EPA Method 300.0 (A). Dionex IonPac Cation-Exchange Columns Column Formats Dionex IonPac CS19-4µm 0.4 × 250 mm Dionex IonPac CS19 11 0.4 × 250 mm 2 × 250 mm 4 × 250 mm Primary Application High resolution separation of inorganic cations and small polar amines in complex matrices. Separation of inorganic cations and small polar amines in complex matrices. Recommended column for polar amines (alkanolamines and methylamines) and moderately hydrophobic amines (biogenic amines, diamines and polyamines). Nonsuppressed mode when extended calibration linearity for ammonium and weak bases is required. Dionex IonPac CS18 2 × 250 mm Dionex IonPac CS17 0.4 × 250 mm 2 × 250 mm 4 × 250 mm Recommended column for highly hydrophobic and polyvalent amines (biogenic amines and diamines). Dionex IonPac CS16 0.4 × 250 mm 3 × 250 mm 5 × 250 mm Recommended column for disparate concentration ratios of sodium and ammonium. Alkylamines and alkanolamines. Dionex IonPac Cation-Exchange Columns Column Primary Application Dionex IonPac CS15 2 × 250 mm 4 × 250 mm Disparate concentration ratios of ammonium and sodium. Trace ethanolamine in high-ammonium or highpotassium concentrations. Alkanolamines. Dionex IonPac CS14 2 × 250 mm 4 × 250 mm Aliphatic amines, aromatic amines, and polyamines plus mono- and divalent cations. Dionex IonPac CS12A-MS 2 × 100 mm IC-MS screening column for fast elution and low flow rates required for interfacing with IC-MS detectors. Dionex IonPac CS12A-5µm 12 Formats 0.4 × 150 mm Recommended column for high efficiency and fast 3 × 150 mm analysis (9 minutes) of mono- and divalent cations. Dionex IonPac CS12A 0.4 × 250 mm 2 × 250 mm 4 × 250 mm Recommended column for the separation of mono- and divalent cations. Manganese morpholine, alkylamines, aromatic amines, and quaternary ammonium ions. Dionex IonPac CS5A 2 × 250 mm 4 × 250 mm Recommended column for transition and lanthanide metals analysis. Aluminum analysis. Dionex IonPac SCS 1 2 × 250 mm 4 × 250 mm Operated with nonsuppressed conductivity detection. Can be used when extended calibration linearity for ammonium and amines is required Dionex IonPac Ion-Exclusion Columns Column Formats Dionex IonPac ICE-AS1 9 × 250 mm 4 × 250 mm Dionex IonPac ICE-AS6 Dionex IonPac ICE-Borate 13 Primary Application Ion-exclusion column for fast analysis of aliphatic organic acids and alcohols in complex samples. 9 × 250 mm Ion-exclusion column for aliphatic organic acids, including hydroxy-substituted organic acids, and alcohols in complex samples. 9 × 250 mm Ion-exclusion column ideal for monitoring trace levels of borate in high-purity water. Determination of Common Anions in a Treated Wastewater Sample Column: 2 60 Dionex IonPac AS19 (0.4 250 mm) Eluent Source: Thermo Scientific Dionex EGC KOH (Capillary) Gradient: Potassium hydroxide 10–25 mM from 0 to 10 min, 25–70 mM from 10 to 20 min 13 mM from 17 to 20 min, 10 mM from 20 to 25 min Flow Rate: 10 µL/min Inj. Volume: 0.4 µL Column Temp.:30 °C Detection: Suppressed conductivity, Thermo Scientific Dionex ACES 300, recycle mode Sample Prep.: Filtered, 0.2 µm 5 4 µS Peaks: 1 3 6 -1.0 0 14 Minutes 25 1. Fluoride 2. Chloride 3. Bromide 4. Nitrate 5. Sulfate 6. Phosphate 1.76 mg/L 180 0.42 11.8 96.9 0.94 Sulfur Species Analysis of a Simulated Acid-Gas Scrubber Solution Column: 70 Dionex IonPac AG25/ AS25 4 250 mm Eluent: Potassium Hydroxide: 20 mM from 0 to 5 min, 20–45 mM from 5 to 15 min, 45 mM from 15 to 30 min Eluent Source: Dionex EGC III KOH Flow Rate: 2.0 mL/min Inj. Volume: 25 µL Temperature: 30 °C Detection: Suppressed conductivity, Thermo Scientific Dionex ASRS 300, 4 mm, AutoSuppression™, recycle mode, 223 mA Sample: 3% base diluted 10-fold 1 3 µS 2 0 -10 0 5 10 Minutes 15 20 Peaks: 1. Chloride 2. Carbonate 3. Sulfate 28428 15 Aliphatic Acids in an Acidic Matrix Column: Eluent: Flow Rate: Detection: 1.0 Sample: µS Peaks: 2 1 3 4 5 6 0.0 0 5 10 Minutes 16 15 20 Dionex IonPac ICE-AS6 10 mM Heptafluorobutyric acid 1.0 mL/min Suppressed conductivity with Thermo Scientific Dionex AMMS-ICE Suppressor 0.25% Sulfuric acid, 50 µL 1. Citric 2. Malic 3. Glycolic 4. Lactic 5. Acetic 6. Succinic 0.5 mg/L 1.0 1.0 1.0 1.0 1.0 Determination of Trace Level Ammonium in a 10,000x and 20,000x Higher Sodium Sample Columns: 0.08 A 1 Eluent: 2 µS Flow Rate: 0 0 0.40 2 4 6 B 8 10 1 µS Temperature: Inj. Volume: Detection: Peaks A: 2 Peaks B: 0 0 5 10 Minutes 17 15 20 Dionex IonPac CS16 A: 5 250 mm B: 3 250 mm A: 30 mM Methanesulfonic acid B: 7 mM Methanesulfonic acid for 23 min to 52 mM at 28 min A: 1.0 mL/min B: 0.43 mL/min 40 C 25 µL Suppressed conductivity, Thermo Scientific Dionex CSRS, AutoSuppression, recycle mode 1. Sodium 2. Ammonium 1. Sodium 2. Ammonium CTC-1 Column placed between the Cell Out and Regen In Ports 100 mg/L 0.01 500 0.25 Determination of Trace Level Sodium in a 10,000x Higher Ammonium Industrial Waste Sample Columns: Dionex IonPac CG16, CS16-5µm (5 250 mm) Eluent: 30 mM Methanesulfonic acid Temperature: 40 C Flow Rate: 1.0 mL/min Inj. Volume: 25 µL Detection: Suppressed conductivity, Dionex CSRS™, 4 mm, AutoSuppression, recycle mode Sample Prep.: 1:10 dilution 0.34 2 1 Peaks: 0.24 0 5 10 15 Minutes 18 20 25 1. Sodium 2. Ammonium 0.01 mg/L (ppm) 100 IC Column Troubleshooting The world leader in serving science 19 Proper Maintenance of Your IC System is Required • Take the time to perform periodic maintenance and Save Time Later! • Daily, Weekly, Periodic, and Monthly Maintenance is required for all IC systems • Read the manuals and perform the required maintenance for each component in your system • Eliminate the system first when troubleshooting performance issues 20 Column Start Up Recommendations • The columns are shipped in a storage solution, typically sodium borate for anion columns and MSA for cation columns • Connect the new guard column and pump the Quality Assurance Report (QAR) eluent directly to waste for 30 minutes • Connect the new separator column to the guard column and pump the QAR eluent directly to waste for 30 minutes • Connect the new column set to the hydrated suppressor • Inject the QAR solution multiple times, until consecutive injections give reproducible retention times • Proceed with your application 21 Reproduce the Quality Assurance Report (QAR) • Reproduce the QAR by running the same analytes under the same conditions • Upon initial installation of a column • Upon changing any components in the system • Upon a noticeable change in performance • The QAR includes the analysis of specific ions under specific conditions that tell us about the performance of the column • The results of the QAR analysis can help troubleshoot the system 22 Column Performance Issues • Column Performance Issues • • • • • • • Fronting Tailing Low peak efficiency Abnormal column pressure Abnormal peak resolution Abnormal retention time Unknown peak (ion contamination) • Column Troubleshooting Table from Manuals 23 Fronting • Symptom • Peak starts slow ascent compared with peak end slope µS • All peaks show same phenomenon, if the cause is the column time • Fronting is rarely improved by a column rinse or a reversed wash • Possible causes • Poor column packing • Eluent mismatch for column • Column overload by weakly retained analytes • Column was mishandled, dropped, allowed to dry out • Column damaged due to pulsed pressure fluctuation causing high back pressure • Solution • Dilute sample or inject less • Replace the column 24 Tailing • Symptom • The slope of peak end is gentle compared with the peak start slope µS • All peaks show same phenomenon, if the cause is the column • If tailing more pronounced on early eluters, could be due to poor connections • Possible causes • Poor connections, especially in capillary systems • High sample concentration or high sample volume (overload) • Contamination/sample adsorbed onto column resin (e.g. SO42-, PO43-, non-ionic surfactant, metal) • Head space or space between resin beads in column • High column back pressure • Drying of resin bed • Solution • Remake fittings one at a time until source is identified • Dilute sample or inject less • Clean column • Replace column 25 time Low Peak Efficiency • Symptom • Broad peak or split peak • Possible Cause • Excessive void volume (Sample diffusion in microbore system or capillary system) • Wrong eluent or wrong sample solvent • Sample adsorbed onto column resin • Contamination of bed support by sample or eluent • Poor column packing • Solution • • • • • 26 Eliminate voids, leaks in the system Use correct eluent Dilute sample in water Clean column, replace inlet bed support Replace column Abnormal Column Pressure (High) • Symptom • Increased operating pressure over time • System shut down due to high pressure • Long or short retention times • Possible Cause • Pump operating improperly • Higher pressure produces shorter retention times • Lower pressure produces longer retention times • • • • • • 27 Clogging in system Crimped tubing Contamination of column Low column temperature Mismatched eluent or organic solvent Injection of sample that is insoluble in mobile phase Abnormal Column Pressure (High) continued • Solution • • • • • • 28 Remove blockage in system Check all connections for uneven flow, remake connections Filter samples Clean column, replace bed support Use correct eluent Verify that oven temperature control is operating correctly Abnormal Column Pressure (Low) • Symptom • Low pressure • Possible Cause • Pump lost prime • Liquid leak • High column temperature • Solution • • • • 29 Prime the pump Eliminate leak Check pump seals Use correct temperature Abnormal Resolution • Symptom • Peaks not resolved • Possible Cause • • • • • Column contamination Headspace in column High sample concentration or high sample volume Disparate concentrations Incorrect eluent • Solution • • • • • 30 Use correct eluent Clean column/replace bed support Dilute sample or inject less Choose correct column Replace column Abnormal Retention Time (Shorter) • Symptom • Shortened retention time during operation • Different retention time compared with previous batch of column • Possible Cause • • • • • • • • 31 Incorrect eluent Improper storage method Column contamination Column overload Incomplete mixing of eluent in eluent container Pump not operating properly Wrong temperature being used Small lot to lot variances in column manufacturing Abnormal Retention Time (Shorter) continued • Solution • • • • • Use correct eluent and storage solution Clean column, replace bed supports Dilute sample or inject less Make sure eluent is properly mixed Ensure pump is operating properly • Operate column under recommended conditions 32 Abnormal Retention Time (Longer) • Symptom • Increased retention time during operation • Different retention time compared with previous batch of column • Possible Cause • Incorrect eluent • Pump not operating properly • Small lot to lot variances in column manufacturing • Solution • Use correct eluent and storage solution • Ensure pump is operating properly 33 Abnormal Retention Time (Varying) • Symptom • Varying retention time during operation • Possible Cause • • • • Not column related Pump not operating properly Injection valve not operating properly Lack of temperature control • Solution • Ensure pump is operating properly, prime the pump • Repair or replace injection valve • Ensure column temperature is stable 34 Spurious Peaks • Symptom • Unexpected peaks in chromatogram • Possible Cause • If unusually wider than others, the spurious peak is from the previous injection • If narrower than others, the spurious peak is from electronic source • Excessive suppressor current • Solution • Increase time between injections • Use recommended suppressor current • Repair or replace injection valve 35 Troubleshooting in Column Manual Observation Cause Action High Backpressure Unknown Isolate Blocked Component Plugged Column Bed Support Replace Bed Supports, Filter Eluents and Samples Other System Components Unplug or Replace Large System Void Volumes Replumb the System Column Headspace Replace the Column Flow Rate Too Fast Calibrate the Pump Incorrect Eluent Concentration Remake the Eluent Column Contamination Clean the Colum Poor Resolution Shortening Retention Time Please see the column or system manual for details 36 Troubleshooting in Column Manual Observation Cause Action Poor Front End Incorrect Eluent Concentration Remake Eluent Resolution Column Overloading Reduce Sample Size Sluggish Injection Valve Service Valve Large System Void Volumes Replumb the System Sample Contaminated Pretreat Samples Sluggish Injection Valve Service Valve No Injection Check Configuration File Spurious Peaks No Peaks Please see the column or system manual for details 37 © 2012 Thermo Fisher Scientific Inc. 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