Ion Chromatography: Green Chemistry for a Green Environment. Ken Kirkbride Somerset, New Jersey October 12, 2011

Transcription

1 Ion Chromatography: Green Chemistry for a Green Environment Ken Kirkbride Somerset, New Jersey October 12, 2011

2 Ion Chromatography Ion Chromatography is an analytical technique that utilizes ion exchange mechanisms to separate ionic substances followed by detection utilizing conductivity, amperometry, UV/Vis, fluorescence or mass spectrometry detectors. Analyte classes include: Anions Cations Organic Acids Amines Transition Metals 2

3 Regulatory Methods that Use Ion Chromatography Chemical or Contaminant Anions ASTM D4327 D4327 D5794 D5827 E1787 WK 5500 E1787 EPA Method Description ISO Method The Determination of Inorganic Anions in Water by Ion Chromatography The Determination of Inorganic Anions in Drinking Water by Ion Chromatography Standard Guide for Determination of Anions in Cathodic Electro-Coat Permeates by Ion Chromatography Test Method for Analysis of Engine Coolant for Chloride and Other Anions by Ion Chromatography Standard Test Method for Anions in Caustic Soda and Caustic Potash (Sodium Hydroxide and Potassium Hydroxide) by Ion Chromatography Standard Test Method for Chloride at Trace Levels in Monoethylene Glycol (Ion Chromatography Method) Standard Test Method for Anions in Caustic Soda and Caustic Potash Water Quality Determination of Dissolved Fluoride, Chloride, Nitrite, Orthophosphate, Bromide, Nitrate and Sulfate Ions, Using Liquid Chromatography of Ions Part 1 Method for Water with Low Contamination 3

4 Regulatory Methods that Use Ion Chromatography Chemical or Contaminant ASTM Bromate ISO EPA Method Description The Determination of Inorganic Anions in Drinking Water by Ion Chromatography D Determination of Bromate by Ion Chromatography Determination of Inorganic Oxyhalide Disinfection By-Products in Drinking 317 Water Using Ion Chromatography with the Addition of a Postcolumn Reagent for Trace Bromate Analysis Determination of Bromate in Drinking Waters by Ion Chromatography Inductively Coupled Plasma Mass Spectrometry Determination of Inorganic Oxyhalide Disinfection By-Products in 326 Drinking Water Using Ion Chromatography Incorporating the Addition of Two Postcolumn Reagents for Trace Bromate Analysis Water Quality Determination of Dissolved Bromate Method by Liquid Chromatography of Ions (ISO 15061:2001); German Version EN ISO 15061:2001 Hexavalent Chromium D Determination of Dissolved Hexavalent Chromium in Drinking Water, Groundwater, and Industrial Wastewater Effluents by Ion Chromatography. (IC with AS16) 4

5 Regulatory Methods that Use Ion Chromatography Chemical or Contaminant ASTM EPA Method Description Perchlorate 314 IC with AS Determination of Perchlorate in Drinking Water Using Inline Column Concentration/Matrix Elimination IC with Suppressed Conductivity. (IC with Cryptand Column) Dimensional IC with the AS20 and AS16 IonPac Columns and Suppressed Conductivity Detection LC-MS/MS Using the IonPac AS21 Column IC-MS and IC-MS/MS with the IonPac AS16 and AS20 Columns WK652 Test Method for Perchlorate in Water by Chemically Suppressed Ion Chromatography Perchlorate Solid Waste Perchlorate Solid Waste Perchlorate in Water, Soils and Solid Wastes Using High-Performance Liquid Chromatography/Electrospray Ionization/Mass Spectrometry Perchlorate in Water, Soils and Solid Wastes Using Ion Chromatography/Electrospray Ionization/Mass Spectrometry 5

6 Regulatory Methods that Use Ion Chromatography Chemical or Contaminant ASTM Cations D Carbohydrate D6919 D5896 Cyanide D Haloacetic Acids EPA Method Description 557 Standard Test Method for Determination of Dissolved Alkali and Alkaline Earth Cations and Ammonium in Water and Wastewater by Ion Chromatography Standard Test Method for Determination of Dissolved Alkali and Alkaline Earth Cations and Ammonium in Water and Wastewater by Ion Chromatography Standard Test Method for Carbohydrate Distribution of Cellulosic Materials (Wood Sugars) Standard Test Method for Determination of Metal Cyanide Complexes in Wastewater, Surface Water, Groundwater and Drinking Water using Anion Exchange Chromatography with UV Detection Determination of Haloacetic Acids, Bromate, and Dalapon in Drinking Water by Ion Chromatography Electrospray Ionization Tandem Mass Spectrometry (IC-ESI-MS/MS) 6

7 Inorganic Anions in Water EPA AND

8 Columns for Carbonate Methods Method 300.0, Part A AS4A, AS14, AS14A, AS22 Bromide Chloride Fluoride N as Nitrate N as Nitrite P as Ortho-phosphate Sulfate Method 300.0, Part B AS9SC, AS9HC, AS23 All above, plus Bromate Chlorite Chlorate Method 300.1, Part A AS9HC, AS14, AS22 Bromide Chloride Fluoride N as Nitrate N as Nitrite P as Ortho-phosphate Sulfate Method 300.1, Part B AS9HC, AS14, AS23 Bromate Bromide Chlorite Chlorate 8

9 Determination of Inorganic Anions in a Municipal Drinking Water Sample µs µs Column: IonPac AG22 and AS22, 4 mm Eluent: 4.5 mm Sodium carbonate/ 1.4 mm sodium bicarbonate Temperature: 30 C Flow Rate: 1.2 ml/min Inj. Volume: 25 µl Detection: Suppressed conductivity, ASRS ULTRA II 4 mm, AutoSuppression recycle mode Peaks 1. Fluoride 0.84 mg/l 2. Formate Chloride Nitrite Unknown NQ 6. Chlorate Bromide Nitrate Carbonate NQ 10. Phosphate Sulfate Very high capacity for anion and organic acid separation 9 9

10 IonPac AS22-Fast Anion Column New Carbonate RFIC Column format Designed for fast, isocratic separation of common inorganic anions in simple sample matrices Has identical selectivity to the IonPac AS22 column Shorter column format decreases dead volume, provides faster run times and allows higher flow rates Higher throughput Up to 2.5 ml/min (4 mm) or 0.63 ml/min (2 mm) Resolve 7 common anions in less than 5 minutes Fast anion analysis with AS22-Fast 10

11 Analysis of a Municipal Drinking Water Sample 100 µs µs Minutes Column: IonPac AS22-Fast, mm Eluent: 4.5 mm Sodium carbonate 1.4 mm Sodium bicarbonate Flow Rate: 2.0 ml/min Inj. Volume: 100 µl Temperature: 30 C Detection: Suppressed conductivity, ASRS 300, 4 mm, AutoSuppression recycle mode Peaks: 1. Fluoride 2. Formate 3. Chloride 4. Nitrite 5. Chlorate 6. Bromide 7. Nitrate 8. Carbonate 9. Phosphate 10. Sulfate Faster than an AS4A but with 6x capacity

12 Though carbonate eluents are easy to prepare Methods using hydroxide eluents offer more sensitivity than those using carbonate eluents. The suppression product is water, providing the lowest possible background conductivity Lower noise Improved detection limits Larger linear working range Preparing hydroxide eluents manually can be difficult to do with high reproducibility. The capillary eluent generator can prepare hydroxide eluents with high accuracy and precision for 18 months 24 hours/day, 7 days/week 12

13 RFIC System for Anions Using EPA Method (A) 20 µs (B) 2 Municipal 6 Drinking Water µs (A) 1 Standard Minutes Column: IonPac AG18, AS18, 4 mm Eluent: mm KOH from 7 8 min Eluent source: ICS-2000 with CR-ATC Temperature: 30 C Flow rate: 1.0 ml/min Inj. volume: 25 µl Detection: ASRS ULTRA, 4 mm recycle mode, 100 ma (A) (B) Peaks: 1. Fluoride mg/l (ppm) 2. Chloride Nitrite Carbonate Bromide Sulfate Nitrate Phosphate Sample: Sunnyvale, CA, drinking water 19115/

14 Hexavalent Chromium EPA

15 Methodologies for Hexavalent Chromium Health concerns Trivalent chromium is nontoxic Hexavalent chromium is highly toxic Traditional analysis method EPA Method chelation extraction, atomic absorption Subject to positive interference from some metals Cumbersome not automated Modest detection limits (~5 µg/l) IC analysis method EPA Method (ASTM Method D ) IC separation of chromium VI coupled with postcolumn reaction 1,5-diphenylcarbizide) UV/Vis detection (530 nm) 15

16 EPA Press Release These modifications allow for improved low concentration measurement and are outlined in Dionex Corp. Application Update 144 Determination of Hexavalent Chromium in Drinking Water by Ion Chromatography found at 16

17 System Configuration for Cr(VI) by EPA Method Eluent Autosampler High-Pressure Nonmetallic Pump Sample Loop IonPac NG1 IonPac AS7 Post column Reagent Mixing Tee Knitted Reaction Coil UV-vis Detector Waste 17

18 Dionex Improvements to EPA Method Application Update 144 Use a lower-sulfate buffer to adjust sample ph Increase sample size to 1000 µl Reduce eluent flow rate to 1 ml/min Reduce PCR flow rate to 0.33 ml/min Increase postcolumn reaction coil to 750 µl New MDL in reagent water is µg/l 18 ppt 15x lower detection limit than Method

19 Hexavalent Chromium in Drinking Water with Optimized EPA Method AU 0 (A) (B) Cr(VI) µg/l Cr(VI) µg/l Minutes Column: IonPac NG1, AS7 Eluent: 250 mm/l (NH 4 ) 2 SO mm/l NH 4 OH Flow rate: 1.0 ml/min Inj. volume: 1000 µl Postcolumn reagent: 2 mm/l 1,5-diphenylcarbizide 10 % MeOH 0.5 mol/l H 2 SO 4 Postcolumn flow rate: 0.33 ml/min Reaction coil: 750 µl Detection: Sample: UV/Vis, 530 nm Sunnyvale, CA, tap water (A) Spiked with 0.2 µg/l Cr(VI) (B) Tap water 19

20 Cr(VI) 2mm using ICS-2100 with AXP High Ionic Strength Water (HIW) vs. DI Water 3.3 mau Column: IonPac AS7 (2 x 50 mm), AS7 (2 x 250 mm) Eluent: 250 mm (NH 4 ) 2 SO 4, 100 mm NH 4 OH Flow: 0.36 ml/min Inj. Vol: 1000 µl Post Column Reagent: 2 mm diphenylcarbazide 10% methanol 1N sulfuric acid Reaction Coil: 125 µl UV Cell: Semi micro (PEEK), 2.5 µl 0.1 µg/l Cr(VI) in DI water 0.1 µg/l Cr(VI) in HIW A Signal offset Minutes B 21

21 Cr(VI) Analysis using 2 mm format 2.5 mau C B A Column: IonPacNG1 (2 x 50 mm), AS7 (2 x 250 mm) Eluent: 250 mm (NH 4 ) 2 SO 4, 100 mm NH 4 OH Flow: 0.36 ml/min Inj. Vol: 1000 µl Post Column Reagent: 2 mm diphenylcarbazide 10% methanol 1N sulfuric acid Reaction Coil:125 µl A) DI water blank B) µg/l Cr(VI) in DI water C) Sunnyvale, CA drinking water 0.05 µg/l Minutes 22

22 Format comparison Format Chromate Conc. (µg/l) Method Detection Limits for Chromate Based on a 1000 µl Injection Std. Dev. (µg/l) RSD (%) MDL* (µg/l) 4 mm mm ppt detection with 2 mm Format! 23 * MDL = (Std. Dev.) x (t s, 99 ), where t s,99 = 3.14 for n = 7

23 Drinking Water Disinfection By-products: Bromate and HAA s EPA 300.1,

24 EPA (B); Trace analysis of bromate using the IonPac AS µs µs Minutes Minutes Carbonate Eluent: AS23 > capacity than AS9HC Columns: IonPac AG23, AS23, 4 mm Eluents: 4.5 mm Sodium carbonate/ 0.8 mm sodium bicarbonate Temperature: 30 C Flow Rate: 1.0 ml/min Inj. Volume: 200 µl Detection: Suppressed conductivity, ASRS ULTRA II, 4 mm, AutoSuppression external water mode Peaks: 1. Fluoride 1.0 mg/l (ppm) 2. Chlorite Bromate Chloride Nitrite Chlorate Bromide Nitrate Carbonate Phosphate Sulfate

25 RFIC System for Anions Using EPA Method (B) 300 µs µs , Column: IonPac AS19, 4 x 250 mm Eluent : 10 mm KOH from 0 to 7 min, 10 to 15 mm from 7 to 20 min, 15 to 55 mm from 20 to 30 min Eluent Source: EGC-KOH cartridge with CR-ATC Flow Rate: 1.0 ml/min Temperature: 30 C Suppressor: ASRS ULTRA, 4 mm, external water mode, 300 ma Inj Volume: 500 µl Peaks: 1. Fluoride 1 mg/l (ppm) 2. Formate 3. Chlorite Bromate Chloride Nitrite Chlorate Bromide Nitrate Carbonate Sulfate Phosphate Minutes Hydroxide Eluent: Allows the use of RFIC (just add water) a 26

26 Oxyhalides and Inorganic Anions in Drinking Water Column: IonPac AS19 ( mm) Eluent Source: Capillary EGC-KOH cartridge Eluent: KOH min) Flow Rate: 10 mm KOH (0 to 10 min), 10 to 50 mm (10 to 25 min), 10 mm KOH (25 to µl/min Inj. Volume: 10 µl Sample A Standard Temperature: 30 C Suppressor: Suppressed conductivity, ACES 300 anion capillary electrolytic suppressor µs Minutes Concentration (µg/l) Peaks: Standard Sample A 1. Chlorite Bromate Chloride Nitrite Chlorate Bromide Nitrate Carbonate 9. Sulfate Phosphate

27 Bromate Method Summary Technique IC-Suppressed Conductivity EPA Method(s) (B) IC-Suppressed Conductivity Column(s) Eluent MDL (ppb) AS9-HC AS23 AS-19 AS9-HC AS23 AS-19 Carbonate Carbonate Hydroxide Carbonate Carbonate Hydroxide Conductivity D IC Suppressed Conductivity (pending) AS19 4mm, AS- 24, 2mm Hydroxide IC - Suppressed Conductivity with postcolumn ODA AS9-HC AS-19 Carbonate Hydroxide Cond. UV IC - Suppressed Conductivity with postcolumn acidified KI AS9-HC AS-19 Carbonate Hydroxide IC-ICP-MS CarboPac PA100 Hydroxide

28 HAA s Without Derivatization United States Environmental Protection Agency TECHNICAL SUPPORT CENTER OFFICE OF GROUND WATER AND DRINKING WATER U. S. ENVIRONMENTAL PROTECTION AGENCY CINCINNATI, OHIO Office of Research and Development: December 2009 Method DETERMINATION OF HALOCAETIC ACIDS, BROMATE, AND DALAPON IN DRINKING WATER BY ION CHROMATOGRAPHY ELECTROSPRAY IONIZATION TANDEM MASS SPECTROMETRY (IC/ESI-MS/MS) A. D. Zaffiro and M. Zimmerman (Shaw Environmental, Inc.) B. V. Pepich (U.S. EPA, Region 10 Laboratory) Rosanne W Slingsby, R. F. Jack and Christopher A. Pohl (Dionex Corporation) D. J. Munch (U.S. EPA, Office of Ground Water and Drinking Water) 29 Developed by Dionex

29 What Are HAAs? Acid Monochloroacetic acid Abbreviation Chemical Formula pka Boiling Point C MCAA* ClCH 2 CO 2 H Dichloroacetic acid DCAA * Cl 2 CHCO 2 H 1.25 a, 1.29 b, 1.30 c 194 Trichloroacetic acid TCAA * Cl 3 CCO 2 H 0.63 a, 0.65 b, 0.70 c Monobromoacetic acid MBAA * BrCH 2 CO 2 H 2.87 a, 2.86 b, 2.7 c 208 Dibromoacetic acid DBAA * Br 2 CHCO 2 H NA 195 Tribromoacetic acid TBAA Br 3 CCO 2 H Bromochloroacetic acid Dibromochloro acetic Acid Dichlorobromoacetic acid BCAA BrClCHCO 2 H NA DBCAA Br 2 ClCCO 2 H NA NA DCBAA Cl 2 ClCCO 2 H NA NA * MCAA, DCAA, TCAA, MBAA, DBAA are collectively referred to as HAA

30 US EPA Method Reported Detection Limits (GC-ECD) Advantages: Good selectivity Low MDLs Wide applicable concentration range: µg/l Analyte Detection Limits (µg/l) % Recovery MCAA MBAA DCAA Limitations: Requires sample pretreatment Time consuming Labor intensive Subject to multiple procedural errors BCAA DBAA TCAA BDCAA CDBAA TBAA

31 EPA 557: Determination of Bromate, Dalapon, and HAA9 by Direct Injection Using IC-MS/MS Diverted to waste Cl - SO 4 CO 3 NO 3 Intensity, cps No sample preparation!

32 Linearity and Minimum Detection Limits of 9 HAAs in DI Water and High Salt Matrix Analyte ISTD 5 μg/l R 2 (Calibration range μg/l) DIW / Matrix* MDL μg/l / %RSD (n=7, 1 μg/l) DI water MDL μg/l / %RSD (n=7, 1 μg/l) In Matrix* MCAA / / / 14.7 MCAA-2-13C MBAA / / / 4.2 DCAA / / / 3.3 BCAA DCAA-2-13C / / / 0.8 DBAA / / / 10.8 TCAA / / / 0.3 BDCAA / / / 18.9 TCAA-2-13C CDBAA / / / 16.4 TBAA / / / * Matrix (mg/l) : SO ; Cl 250; NO 3 30; NH 4 Cl 100; HCO 3 150;

33 Perchlorate EPA 314.0, AND

34 Perchlorate EPA Method Summary (Lowest Concentration Minimum Reporting Level) Technique EPA MDL in Water LCMRL ppb Column(s) IC-Suppressed Conductivity 314.0* ppb na AS16 or AS20 IC-Suppressed Conductivity Matrix Rinse-Elimination Primary and Confirmation Columns 2-D IC Suppressed Conductivity Matrix Rinse-Elimination Primary and Confirmation Columns 314.1* ppb * AS16 AS20 AS16 AS20 with TAC-ULP IC-MS 332.0** 6860 IC-MS/MS 332.0** 6860 *Developed by Dionex ppb ppb AS16 or AS20 AS16 or AS20 ** Jointly developed by EPA and Dionex

35 EPA Method Determination of 1 µg/l Perchlorate with Increasing Concentrations of Chloride, Sulfate, and Carbonate Column: IonPac AG16, AS16, 4 mm Eluent: 65 mm KOH Eluent Source: ICS-2000 EG with CR-ATC Temperature: 30 C Flow Rate: 1.2 ml/min Injection loop: 1000 µl Detection: ASRS ULTRA II, AutoSuppression, external water mode, 193 ma Peaks: 1. Perchlorate 1 µg/l Samples: MA(x) = X mg/l each Cl, SO 4 2, CO

36 2-D Perchlorate Analysis in High-Ionic Strength Water 1.35 µs A: First Dimension 1. Perchlorate A) First Dimension Column: IonPac AG20, AS20, 4 mm Eluent: 35 mm KOH, 0-30 min; mm, min Eluent Source: EG with EGC II KOH Flow Rate: 1.0 ml/min Inj. Volume: 4000 µl Temperature: 30 C Detection: suppressed conductivity, ASRS ULTRA II, 4 mm, 150 ma Concentrator B: Second Dimension Injection B) Second Dimension Concentrator: TAC-ULP1 (5 x 23 mm) Column: IonPac AG16, AS16, 2 mm Eluent: 65 mm KOH Eluent Source: EG with EGC II KOH Flow Rate: 0.25 ml/min Cut Volume: 5 ml Temperature: 30 C Detection: suppressed conductivity, ASRS ULTRA II, 2 mm, 41 ma µs Minutes 1 Peak: Matrix: Chloride: 1000 mg/l Bicarbonate: 1000 Sulfate: Perchlorate 0.5 µg/l Accurate detection even in difficult matrices 37

37 Benefits of Combining Suppressed IC with Mass Spectrometry Detection Separate ionic analytes using standard IC conditions Suppressor permits use of high ionic strength eluents to get the benefits of high capacity columns Dionex ICS-5000 with MSQ Plus Detect and identify analytes with high specificity Avoid coeluting interferences to ensure accurate identification Avoid background interferences to ensure highest analyte sensitivity Identify analytes by mass and isotope ratios for added confirmation Internal standard adds to method robustness Identify unknowns 38

38 EPA Method 332.0* IC-MS(/MS) System with Matrix Elimination H 2 0 Chromatography Pump Eluent Generator Injector IC Column Matrix Elimination Valve Suppressor Column Flow to Waste (Matrix Elimination) Column Flow to MSQ MSQ Mass Spec Waste * Jointly developed by EPA and Dionex H 2 0 / ACN Auxiliary Pump Waste 39

39 Advantages of MS Detection vs Conductivity Detection for Perchlorate Much greater sensitivity MRL on order of 5 50 ppt Specific determination of two perchlorate isotopes Unique perchlorate isotope ratios Oxygen-18 Perchlorate isotope can be used as an internal standard for improved method robustness Avoids inaccurate identification due to coeluting interferences Sensitivity maintained even in high TDS matrices MS detection is inherently confirmatory 40

40 Use of Perchlorate Oxygen-18 Isotope (m/z = 107) as an Internal Standard Ensures Measurement Precision % Recovery Area Counts ISTD Calc Perchlorate Conc (ppt) High TDS Matrix: Chloride 1000 ppm Carbonate 1000 Sulfate

41 Perchlorate in California Groundwater EPA Method (IC-MS)* 18,000 SIM 99 Counts Conductivity SIM 99 4 µs Column: IonPac AG16, AS16, 2 mm i.d. Suppressor: ASRS ULTRA, 2 mm Eluent: 65 mm KOH (EG40) Flow Rate: 0.30 ml/min Inj. Volume: 250 µl Detection: 1. Conductivity 2. MSQ, SIM 99, 35 CIO 4 MS Conditions: ESI, 70 V, 350 C Sample: Groundwater diluted 1/10 Peak: Perchlorate ~ 7 8 μg/l SIM 101 (MDL) 99 ** = 0.04 ppb * Method developed jointly by EPA and Dionex Minutes ** MDL = SD t s (n = 7), t s =

42 Perchlorate Analysis Using IC-MS with Matrix Diversion and 50% Acetonitrile Solvent Wash EPA Method 332.0* 1600 Counts SIM ppb Perchlorate with 1000 ppm each CCS** 2 1 ppb Perchlorate with 600 ppm each CCS** 3 1 ppb Perchlorate with 100 ppm each CCS** **CCS = Chloride, Carbonate, Sulfate Retention Time, Min * Method developed jointly by EPA and Dionex 43

43 44 ThermoFisher is committed to IC Environmental Methods