### METHOD 300.0 DETERMINATION OF INORGANIC ANIONS BY ION CHROMATOGRAPHY

John D. Pfaff Inorganic Chemistry Branch Chemistry Research Division

Revision 2.1 August 1993

ENVIRONMENTAL MONITORING SYSTEMS LABORATORY OFFICE OF RESEARCH ANO DEVELOPMENT U.S. ENVIRONMENTAL PROTECTION AGENCY CINCINNATI, OHIO 45268

300.0-1METHOD 300.0 DETERMINATION OF INORGANIC ANIO N

SBY ION CHROMATOGRAPHY
1.0 SCOPE AND APPLICATION 1.1 This method covers the determ1nat1on of the following inorganic anions: PART fl. Bromide Chloride Fluoride Nitrate PART B. Bromate Chlorate N itrite Ortho-Phosphate-P Sulfate

Chlorite
1.2 The m.1lrices applicable to each method are shown below: fl. Drinking water, surface water. mixed domestic and industrial wastewdters, groundwater, reagent waters. solids (after extraction 11.7), leachates (when no acetic acid is used). B. Drinking water and reagent waters 1.3 The single laboratory Method Detect1on Limit (MOL defined in Sect. 3.2) ror the above analytes is listed in Tables lA and lB. The M OL for a specificmatrix may d1ffer from those listed, depending upon the nature orthe sample. 1.4 M eLhod Ais recommended for drinking and wastewaters. The mullilaboratory ranges tested for each anion are as follows: Analyte Brom1de Chlonde

**~**1uoride N

itrate-N Nitrite

-N Orth o-Ph osphate-P Sulfate mLI. 0.63

- 21.0 0.78- 26

.0 0.26

- 8.49 0.42

- 14.0 0.36

- 12.0 0

.69

- 23

.I 2

.85

- 95.0

300.0

-21.5

**Thi~** method is recommended for use only by or under the superv1s1on of analysts experienced In the use of 1on chromatography and in the interpretation ofthe rpsulting 1on chromatograms. 1.6 When this method is used to analyze unfamiliar samples for any of the above anions, anion ldentiftcation should be supported by the use of a fortified sample matrix covertng 

### the anions of Interest. The fortification pror.eclure is described in Sect. 11.6. 

### 1.7 Users of the method 

### data should state the data-quality objectives prior to analysis. Users of the method

**mu~t** demonstrate the ability to generate acceptable results w1th this melhod, using the procedures described in Sect

. 9.0.

2.1 Asmall volume of sample, typically 2 to 3 ml, is introduced into an ion chromatograph. The anions of interest are separated and measured, using a system comprised of a guard column, analytical column, suppressor device, and conductivity detector. 2.2 lhe main differences between Parts Aand 8 are the separatorcolumns and guard columns. Sections 6.0 and 7.0 will elicit the differences. 2.3 An extraction procedure must be performed to use this method for solids (See 11.7). 2.4 Limited performance

-based method modifications may be acceptable provided they are fully documented and meet or cxcPed requirements expressed in Sect. 9.0, Quality Control. 3.0 DEFINITIONS 3.1 CALIBRATION BLANK (CB)

-- Avolume ofreagent watpr fortified with the same matrix as the calibration standards, but without the analytes, internal standards, or surrogate

**analytP~**

**.** 3.2 CALIBRATION STANDARD (CAL)

-- Asolution prepared from the prtmary dilution stdndard solution or stock standard solutions and the internal standards and surrogate analytes. The CAL solutions are used to calibrate the instrument response with respect to analyte concentration. 3.3 FIELD DUPLICATES (FD)

-- Two separate samples collected at the same time and place under identical circumstances and treated exactly the same throughout field and laboratory procedures. Analyses of field duplicates 1ndicate the precision assoc1ated with sample collection, preservation and storage, as well as with laboratory procedures. 3.4 INSTRUMENT PERFORMANCE CHECK SOLUTION (IPC)

-- A

**~olution** ofone or more method analytes,

**~urrogates,** internal standards, orothertest 300.0-3substances used to evaluate the performance ofthe instrument system with respect to a defined set ofcriteria. 3.5 LABORATORY FORTIFIED CLANK (LFB) --An aliquot of reagent water or other blank matrices to which known quantities of the method analytes are added in the laboratory. The LFB is analyzed exactly like a sample, and its purpose is to determine whether the methodology is in control, and whether the laboratory is capable of making accurate and precise measurements. 3.6 LABORATORY FORTIFIED SAMPLE MATRIX (LFM)

-- An aliquot of an environmental sample to which known quantities ofthe method analytes are added in the laboratory. The LFM is analyzed exactly like a sample, and its purpose is to determine whether the sample matrix contributes bias to the analytical results. The background concent1·ations of the analytes in the sample matrix must. be determined in a separate aliquot and the measured values in the LFM corrected for background concentrations. 3.7 LABORAlORY REAGENT BLANK (LRB) --An aliquot of reagent water or other blank matrices that are treated exactly as a sample including exposure to all glassware, equipment, solvents, reagents, internal standards, and surrogates that are used with other samples. The LRB is used to determine ifmethod analytes or other interferences are present in the laboratory environment, the reagents, or the apparatus. 3.8 LINEAR CALIBRATION RANGE (LCR) --The concentration range over which the instrument response is linear. 3.9 MATERIAL SAFElY DATA SHEET (MSDS)

-- Written information provided by vendors concerning a chemical's toxicity, health hazards, physical properties, fire, and reactivity data including storage, spill, and handling precautions. 3.IO METHOD DETECTION LIMIT (MDL) --Theminimum concentration

# of an analyte that can be identified, measured and reported with 99% confidence that the analyte concentration is greater than zero. 3.11 PERFORMANCE EVALUATION SAMPL[ (P[) --A solution ofmethod analytes distributed by the Quality Assurance Research Division (QARO), Environmental Monitoring Systems Laboratory ([MSL-Cincinnati), U. S. Environmental Protection Agency, Cincinnati, Ohio, to multiple laboratories for analysis. Avolume ofthe solution is added to a known volume of reagent water and analyzed with procedures used for samples. Results of analyses are used by QARO to determine statistically the accuracy and precision that can be expected when a method is performed by a competent analyst. Analyte true values are unknown to the analyst. 3.12 QUALITY CONTROL**SA~1PLE** (QCS)

-- Asolution ofmethod analytes of known concentrations that Is used to fortify an aliquot of LRB or 300.0-4sample matrix. The QCS is obtalned from a source external to the laboratory and different from the source or calibration standards. It is used to check 1 aboratory performance with externa11y

**pr~pared** test materia1s. 3.13 STOCK STANDARD SOLUTION (SSS} --A

**concentr~ted** solutioncontaining one ormore method analytes prepared in the laboratory using assayed reference materials orpurchased from areputable commercial source. 4.0 IN TERFEREN CES 4.1 Interferences can be caused by substances wilh retention times that are similar to and overlap those ofthe anion of interest. Large amounts of an anion can 1nterfere with the peak resolution ofan adjacent anion. Sample dilutton and/or fortification can be used to solve most interference problems associated with retention times. 4.2 The water dip or negative peak that elutes ncar, and can Interfere with, the fluoride peak can usually be eliminated by the addition of the equivalent of 1ml ofconcentrated eluent (7.3 IOOX) to 100 ml ofeach standard and sample. 4.3 Method Interferencesmay be caused by contdminants in the reagent water, reagents. glassware. and other

**~ample** processing apparatus that lead to discrete artifacts or elevated

**bas~line** In 1on chromatograms. 4.4 Samples that contain particles larger than 0.45 microns and reagent solutions that contain particles larger than 0.20 microns require filtration to prevent damage to Instrument columns and flow systems. 4.5 Any anion that is not retained by the column or only slightly retained will elute in the area or fluoride and interfere. Known coelutlon Is caused by carbonate and other small organic anions. At concentrations of fluoride above 1.5 mg/L. this interference may not be significant, however. it is the responsibilityof the user to gPnerate precision and accuracy information in each sample matrix. 4.6 The acetate anion elutes earlyduring the chromatographic run. The retention times ofthe antons also seem to differwhen large amounts of acetate are present. Therefore, thh method is not recommended for leachates of solid samples when acetic dCid is used for pH adjustmP.nt.. 4.7

**Th~** quantlt.atlon ofunretained peaks should be avoided, such as low molecular weight organic actds (formate, acetdte, propionate etc

.) which arc conductive and coelute wtth or neir fluoride and would bias the fluorldP quantitation 1n some drinking and most waste waters. 4.8 Any residual chlorinedioxide present in the sample will result In the formation of andltional chlorite prior to analysis. If any 300

.0-55.0 SAFETYconcentration ofchlorine dioxide is suspected in the sample purge the sample with an inert gas (argon or nitrogen) for about five minutes or until no chlorine dioxide remains.

5.1 The toxicity or carcinogenicity ofeach reagent used in this method have not been fully established. Each chemica1 should be regarded as a potential health hazard and exposure should be as low as reasonably achievable. Cautions are included for known extremely hazardous materials orprocedures. 5.2 Each laboratory is responsible for maintaining a current awareness file ofOSHA regulations regarding the safe handling ofthe chemicals specified in thismethod. Areference file ofMaterial Safety Data Sheets (MSDS) should be made available to all personnel involved in the chemical analysis. The preparation of a formal safety plan is also advisable. 5.3 The following chemicals have the potential to be highly toxic or hazardous, consultMSDS. 5.3.1 Sulfuric acid (7.4) 6.0 Equipment and Supplies 6.1 Balance-- Analytical, capable of accurately weighing to the nearest 0.0001 g. 6.2 Ion chromatograph

-- Analytical system complete with ion 'hromatograph and all required accessories including syringes, analytical columns, compressed gasses and detectors. 6.2.1 Anion guard column: Aprotector of the separator column. If omitted from the system the retention times will be shorter. Usually packed with a substrate the same as that in the separator column. 6.2.2 Anion separator column: This column produces the separation shown in Figures I and 2. 6.2.2.1 Anion analytical column (Method A): The separation shown in Figure I was generated using a Olonex AS4A column (P/N 37041). An optional column may be used ifcomparable resolution of peaks is obtained, and the requirements ofSect. 9.2 can be met. 6.2.2.2 Anion analytical column (Method C). The separation shown in Figure 2 was generated using a Dionex AS9 column (P/N 42025). An optional column may be used ifcomparable resolution ofpeaks is 300.0-6obtained and the requirements of Sect. 9.2 can be met. 6.2.3 Anion suppressor device: The data presented in this method were generated using aDlonex anion micro membrane suppressor (P/N 37106}. 6.2.4 Detector

-- Conductivity cell: approximately 1.25

**~l** internal volume, {Dionex, orequivalent} capable of providing data as required in Sect. 9.2. 6.3 The Dionex Al-450 Data Chromatography Software was used to generate all the data in the attached tables. Systems using a strlpchart recorder and integratororothercomputer based data systemmay achieve approximately the same MOL's but the user should demonstrate this by the procedure outlined in Sect. 9.2. 7.0 Reagents and Standards 7.1 Sample bottles: Glass orpolyethylene of sufficient volume to allow replicate analyses of anions ofinterest. 7.2 Reagent water: Distilled or deionized water, free ofthe anions of interest. Water should contain particles no larger than 0.20 microns. 7.3 Eluent solution (Method Aand Method 8): Sodium bicarbonate (CASRN 144-55-8} 1.7 mM, sodium carbonate (CASRN 497-19-8) 1.8mM. Dissolve 0.2856 9 sodium bicarbonate (NaHC03} and 0.3816 9 of sodium carbonate (lla2C03) In reagent water (7.2) and dilute to 2 L. 7.4 Regeneration solution (micro membrane suppressor): Sulfuric acid {CASRN-7664

-93

-9} 0.025N. Dilute 2.8 ml cone. sulfuric acid {H2S04} to 4 l with reagent water. 7.5 Stock standard solutions, 1000 mg/L (1 mg/ml): Stock standard solutions may be purchased as certified solutions or prerared from ACS reagent grade matPrials (dried at 105•c for 30 min) as listed below. 7.5.1
7.5.2

7.5.3 Bromide (Br') 1000

### mgJL: Dissolve 1.2876 g sodium bromide (NaBr, CASRN 7647-15-6} in reagent water and dilute to J l. Bromate {Br03') 1000 mg/L: Dissolve 1.1798y of sodium bromate {NaBr03, CASRN 7789-38-0) 1n reagent water and dilute to I l. Chlorate {C103') 1000 mg/L: Dissolve 1.2753g of sodium chlorate (NaC!03, CASRN 7775-09-9} in reagent water and dilute to I l.

300.0

-77.5.4

7.5.5

7.5.6
7.5.7

7.5.8

7.5.9

7.5.10 Chloride (CL') 1000 mg/L: Dissolve 1.6485 g sodium chloride (NaCl, CASRN 7647-14-5) in reagent water and dilute to 1 L. Chlorite**(C10~")** 1000 mg/L: Dissolve 1.3410g of sodium chlorite (NaC!02, CASRN 7758-19-2) in reagent water and dilute to 1 L. Fluoride (F") 1000 mgJL: Dissolve 2.2100g sodium fluoride (NaF, CASRN 7681-49-4) in reagent water and dilute to l L. Nitrate (NO" -N) 1000 mg/L: Dissolve 6.0679 g sodium nitrate (NaJo3, CASRN 7631-99-4) in reagent water and dilute to 1 L. Nitrite (NO" -N) 1000 mg/L: Dissolve 4.9257 g sodium nitrite

### (Na~**•** CASRN 7632-00-0) in reagent water and d i1 ute to 1 L. Phosphate (PO" -P) 1000 mg/L: Dissolve 4.3937 g potassium phosphate (KH)'Ot, CASRN 7778-77-0) in reagent water and dilute to 1

. Sulfate (S04"} 1000 mg/L: Dissolve sulfate**(K~S0 ,**  CASRN 7778-80-5} in dilute to J L. 1.8141 g potassium reagent water and
NOTE: Stability of standards: Stock standards (7.5} are stable for at least 1month when stored at 4"C. Except for the chlorite standard which is only stable for two weeks. Dilute working standards should be prepared weekly, except those that contain nitrite and phosphate should be prepared fresh daily. 7.6 Ethylenediamine preservation solution: Dilute 10 ml of ethylenediamine (99%} (CASRN 107-15-3} to 200 ml with reagent water. Use 1ml ofthis dilution to each 1 l of sample taken. 8.0 sample Collection. Preservation and Storage 8.1 Samples should be collected in plastic orglass bottles. All bottles must be thoroughly cleaned and rinsed with reagent water. Volume collected should be sufficient to insure a representative sample, allow for replicate analysis, if required, and minimize waste disposal. 8.2 Sample preservation and holding times for the anions that can be determined by this method are as follows: Analyte Bromate Preservation None required 300.0-8 Holdjng [ime 28 days

### Bromide Chlorate Chloride Chlorite 

### nuoride Nitrate-N Combined (Nitrate/Nitrite} Nitrite-N 0-Phosphate-P Sulfate tlone required tlone required tlont> requirt>d Cool to 4°C None requ1red Cool to 4'C cone. HzS04 

### to a pll 

### <2 

### Cool to 4'C Cool to 4'C 

### Cool to 4'C 28 

### days 28 

### days 28 

### days 1nrnedately 28 

### days 48 hours 28 

### days 48 hours 48 

### hours 28 

### ddyS N

OTE: If the determined value for the combined nitrate/nitrite exceeds 0.5 mg/L as N, a

**re~ample** 

### must be analyzed for the individual concentrations of nitrate and nitrite. 8.3 The method ofpreservation and the holding time for samples analyzed by this method are determined by the anions of interest. In agiven sample, the anion that requires the most preservation treatment and the shortest holding time will determine the preser- vation treatment. It is recommended that all

**~amples** 

### be cooled to 4"C and held for no longer than 28 days for Method Aand analyzed immediately in Method B. N

OTE: If the sample cannot be analyzed for chloritewilhin

## s 10 

### minutes, the sample may be preserved by adding I ml of the ethylenediamine 

### (EDA} preservation solution (7.6) to 

### 1L of sample. This will preserve the concentration of the chlorite for up to 14 

### days. This addition of

### EOA has no effect on bromate or chlorate, so they can also be determined in a sample preserved with 

### EOA. Residual chlorine dioxide should be removed from the sample (per 4.8) prior to the addition of

### EDA. 9.0 QUALITY CONTROL 9.1 

### Each laboratory using this method is required to operate a formal qualitycontrol (QC) program. The minimum requirements of this program consist of an initial demonstration of laboratory capability, and the periodic an,lysis oflaboratory reagent blanks, fortified blanks and other laboratory solutions as a continuing check on performance. The laboratory is required Lo maintain per- formance records that define the quality of the data that are generated. 9.2 INITIAL DEMONSTRATION OF PERFORMANCE 9.2.1 The initial demonstration ofperformance 1s used to characterize instrument performance (determ1nation of LCRs and analysis ofQCS) and laboratory performance
300.0-9(determination ofHOLs) prior toperforming analyses by this method. 9.2.2 Linear Calibration Range (LCR)

-- The LCR must be determined initially and verified every 6 months or whenever 

### a significant change in instrument response Is observed or expected. The initial demonstration of linearitymust use sufficient standards to insure that the resulting curve Is linear. The verification of linearitymust use aminimum of a blank and three standards. If any verification data exceeds the inithl valuP.s by t 10%, linearitymust be reestablished. If any portion of the range is shown to be nonlinear, sufficient standar ds must be used to clearly define the nonlinear portion. 9.2.3 Quality Control Sample (QCS) --When beginning the use of this method, on a quarterly basis or as required to meet data-qualityneeds, verify the calibration standards and acceptable instrument performance with the preparation and analyses of a QCS. If the determined concentrations are not within t 10% of the stated values, performance of the determinative step of the method is unacceptable. The source of the problem must be identified and corrected before eitherproceeding w ith the initial determination of MDls or continuing with on-going analyses. 9.2.4 Method Detection l.imlt (MDL)

-- MDLs must be established for all analytes, using reagent water (blank) fortified at a concentration oftwo to three times the estimated instrument detection limit.<6> To determine MDL values, take seven replicate aliquots of the fortified reagent water and process through thP entire analytical method. Perform all calculationsdeflnPd In the method and report the concentration values 1n the appropriate unlts. Cilcuhte the MDL as

**follow~:**MOL • (t) 

### x (S) where, t - StudPnt's t value for a 99% confidence level and a standard deviation estimate with n-1

**degrep~** offreedom [t • 3.14 for seven rei>l Icates]. S• standard deviation of the replicate analyses. MDLs should be determined every 6 months, when a new operalur begins work orwhenever there is a significant chanye in lhc background or instrument response. 9.3 ASSESSING LABORATORY PERFORMANCE

300.0-109.3.1 laboratory Reagent Blank (lRB)

-- The laboratory must analyze at least one lRB with each batch of samples. Data produced are used to assess contamination from the laboratory environment. Values that exceed the HDl indicate laboratory or reagent contamination should be suspected and corrective actions must be taken before continuing the analysis. 9.3.2 laboratory Fortified Blank (LFB)

-- The laboratory must analyze at least one IFR with each batch of samples. Calculate accuracy as percent recovery

**(S~ct.** 9.4.2). If the recovery of any analyte falls outside the required control limits of 90

-110%, that analyte Is judged out of control, and the source of the problem should be identified and resolved before continuing analyses. 9.3.3 The laboratory must use LFB analyses data to assess laboratory performance against the required control limits of90-110%. When sufficient internal performance data become available (usually a minimum of 20-30 analyses), optional control limits can be developed from the percent mean recovery (x) and the standard deviation (S) of the mean recovery. These data can be used to establish the upper and lower control limits as follows: UPPFR CONTROL LIMIT • X+ 35 LOWFR CONTROL LIHIT =X

- 35 The optional control limits must be equal to or better than the required control limits of 90-110%. After each five to ten new recovery measurements, new control limits can be calculated using only the most recent 20-30 data points. Also, the standard deviation (S) data should be used to establish an on going precision

**state~ent** for the level of concentrations included In the LFB. These data must be kept on file and be available for review. 9.3.4 Instrument Performance Check Solution (IPC)

-- For all determinations the laboratory must analyze the !PC (a midrange check standard) and a calibration blank immediately following daily calibration, after every tenth sample (or more frequently, if required) and at the end of the sample run. Analysis of the !PC solution and calibration blank

**imm~diately** following calibrationmust verify that the instrument is within± 10% ofcalibration. Subsequent andlyses of the IPC solutionmust verify the calibration is still within± 10%. If the calibration cannot be verified within the specified limits, reanalyze the !PC solution. If the second analysis of the JPC solution confirms calibrat1on to be outside the limits, sample analysis must be discontinued, the cause determined andjor in the case of drift, lhe instrument recalibratetl. All samples follow1ng 300.()-11the last acceptable IPC solution must be reanalyzed. The analysis dala of the calibration blank and !PC solution must be kept on file wilh th e sample analyses data

. 9.4 ASSESSING ANALYTE RECOVERY AND DATA QUALITY 9.4.1 Laboratory Fortified Sample Matrix (LFM)

-- The laboratory must add a known amount of analyte to aminimum of 10% of the routine samples. In each case th e LFM aliquot must be a duplicate of the aliquot used for sample an alysis. The analyte concentration must be high enough to be detected above the original sample and should not be less thanf011r times the MDL. The added analyte concentration should he the same as that used in the laboratory fortified blank. 9.4.1.1 If the concentration of fortification is less than 25% of the background concentration of the matrix the matrix recovery should not be calculated. 9.4.2 Calculate the percent recovery for each analyte, corrected for concentrations measured in the unfortified sample, and compare these values to the designated LFM recovery range 90-110%. Percent recovery may be calculated using the following equation:

R• 

## c. - C ....:...._.,....$- )( 100 where, R • percent recovery. C • fortified sample concentration. 

## c• • sample background concentration. s • concentration equivalent of analyte added to sample. 9.4.3 Until sufficient data becomes available (usually am1n1mum of 20 to 30 analysis), assess laboratory performance against recovery limits for method A o f 80 to 120% and 75 to 125% for method B. When sufficient internal performance data becomes available develop con trol limits from percent mean recovery and the standard deviation ofthe mean recovery. 9.4.4 If the recovery of any analyte falls outside the des1gnated LFM recovery range and the laboratory performance for that analyte is shown to be incontrol (Sect. 9.3), the recovery problem encountered with the LFHis judged to be either matrix or solution related, not system related. 9.4.5 W h

ere reference materials are available, they should be analyzed to provide additional performance data. The
300.0-12analysis ofreference samples is a valuable tool for demonstrating the ability to perform the method acceptably. 9.4.6 In recognition ofthe rapid advances occurring in chromatog- raphy, the analyst is permitted certain options, such as the use ofdifferent columns andjor eluents, to improve the separations or lower the cost ofmeasurements. Each time such modifications to the method are made, the analyst is required to repeat the procedure in Sect. 9.2. 9.4.7 It is recommended that the laboratory adopt additional quality assurance practices for use with this method. The specific practices that are most productive depend upon the needs of the laboratory and the nature of the samples. Field duplicates may be analyzed to monitor the precision of the sampling technique. When doubt exists over the identification of a peak in the chromatogram, confirmatory techniques such as sample dilution and fortification, must be used. Whenever possible, the laboratory should perform analysis ofquality control check samples and participate in relevant performance evaluation sample studies. 9.4.8 At least quarterly, replicates of LFBs should be analyzed to determine the precision of the laboratory measurements. Add these results to the on-going control charts to document data quality. 9.4.9 When using Part B, the analyst should be aware of the pur1ty of the reagents used to prepare standards. Allowances must be made when the solid materials are less than 99% pure. 10.0Caljbratjon and Standardization 10.1 Establish ion chromatographic operating parameters equivalent to those indicated in Tables lA or lB. 10.2 For each analyte of interest, prepare calibration standards at a minimum of three concentration levels and a blank by adding accurately measured volumes of one ormore stock standards (7.5) to a volumetric flask and diluting to volume with reagent water. If a sample analyte concentration exceeds the calibration range the sample may be diluted to fall within the range. If this is not possible then three new calibration concentrations must be chosen, two of which must bracket the concentration ofthe sample analyte of interest. Each attenuation range ofthe instrument used to analyze a sample must be calibrated individually. 10.3 Using injections of 0.1 to 1.0 ml (determined by injection loop volume) of each calibration standard, tabulate peak height or area responses**~gainst** the concentration. The results are used to prepare a calibration curve for each analyte. During this pro- c:edure, retention times must be recorded. 300.0-1310.4 

### The calibration curve must be verified on each working day, or whenever the anion eluent is changed, and afterevery 20 samples. If the response or retention time for any analyte varies from the expected values by more than ± 101, 

### the testmust be repeated, using fresh calibration standards. If the results are still more than± 10%, 

### a new calibration curve must be prepared for that analyte. 10.5

### Nonlinear response can resultwhen the separator column capacity is exceeded (overloading). The response of the detectorto the sample when diluted 1:1, 

### and when not diluted, should be compared. Ifthe calculated responses are the same, samples ofthis total anionic concentration need not be diluted. 11.

### 0Procedure 11.1 

### Tables 1A 

### and 18 

### summarize the recommended operating conditions for the ion chromatograph. Included in these tables are estimated retention times that can be achieved by this method. Other columns, chromatographic conditions, or detectors may be used If

### the requirements of Sect. 9.Z are met. 11.2 

### Check system calibration daily and, if required, recallbrate as described in Sect. 10. 11.3 

### load and inject a fixed amount ofwell mixed sample. Flush injection loop thoroughly, using each new sample. Use the same size loop for standards and samples. Record the resulting peak size in area orpeak height units. An automated constant volume injection system may also be used. 11.4 

### The width of the retention time window used to make identifications should be based upon

**measurement~** 

### of actual retention time varia- tions of standards over the course of aday. Three times the standard deviation of aretention lime can be used to calculate a suggested window size for each analyle. However, the experience of the analyst should weigh heavily in the interpretation of chromatograms. 11.5 

### If the response for the peak exceeds the working range of the system, dilute the sample with an dppropriatc amount of reagent water and reanalyze. 11.6 

### Ifthe resulting chromatogram fails toproduce adequate resolution, or if identification of specific anions is questionable, fortify the sample with an appropriate amount or standard and rcanaly7e. NOTE: Retention time is inverselyproportional to concentration. Nitrate and sulfate exh1b1t the greatest amount ofchange, although all anions are affected to some degree. In some cases this peak migration may produce poor resolution or Identification. 300.0-1411.7 

### The following extraction should be used for solid materials. Add an amount ofreagent water equal to ten times the weight ofdry solid material taken as a sample. This slurry ismixed for ten minutes using a

### magnetic stirring device. Filter the resulting slurry before injecting using a0.45 # 

### membrane type filter. This can be thetype that attaches directly to the end ofthe syringe. Care should be taken to show that good recovery and identification of peaks is obtained with the user's matrix through the use of fortified samples. 11.8 

### It has been reported that lower detection limits for

**~ornate** 

### (•7 pg/L) can be obtained using a borate based eluent<>. The use of this eluent orothereluents that improve method performance may be considered as aminor modification of the method and as such still are acceptable. 11.9 

### Should more complete resolution be needed between peaks the eluent (7.3) 

### can be diluted. This will spread out the run but will also cause the later eluting anions to be retained longer. The analyst must determine to what extent the eluent is diluted. This dilution should not be considered a deviation from the method. 12.0DATA ANALYSIS AND CALCULATIONS 12.1 Prepare a calibrat1on curve for each analyte by plotting instrument response against standard concentration. Compute sample concentration by comparing sample response w ith the standard curve. Multiply answer by appropriate dilution factor. 12.2 Report only those values that fall between the lowest and the highest calibration standards. Samples exceeding the highest standard should be diluted and reanalyzed. 12.3 Report results in mg/L. 12.4 Report N02" 

### as N No;· as H HP0 4" 

### as P 

### 13.0METHODS PERFORMANCE 13.1 

### Tables lA and 2A give the single laboratory (EHSL-Cincinnati) MOL fur each anion included in the method under the conditions listed. 13.2

### Tables 2A and 28 give the single laboratory (EHSL-Cincinnati) standard deviation for each anion included in the method in a variety ofwaters for the listed conditions. 13.3 

### Multiple laboratory accuracy and bias data (51) 

### and estimated single operator values (50) 

### for reagent, drinking ana waste water using

JOO.D-15method Aarc given for each anion in Tables 3through 9. Data from 19 laboratorieswere used for this data. 13.4 Some of the bias statements, for example chloride and sulfate, may be misleading due to spiking small increments ofthe anion into large naturally occurring com;entrations ofthe same anion. 14.0 POLLUTION PREVENTION 14.1 Pollution prevention encompasses any technique that reduces or eliminates the quantity or toxicity ofwaste at the point of generation. Numerous opportunities for pollution prevention exist in laboratory operation. The EPA has established a preferred hierarchy ofenvironmental management techniques that places pollution prevention as the management option of first choice. Whenever feasible, laboratory personnel should use pollution prevention techniques to address their waste generation. When wastes cannot be feasibly reduced at the source, the Agency recommends recycling as the next best option. 14.2 Quantity of the chemicals purchased should be based on expected usage during its shelflife and disposal cost of unused material. Actual reagent preparation volumes should reflect anticipated usage and reagent stability. 14.3 For information about pollution prevention thatmay be applicable to laboratories and research institutions, consult "less is Better: laboratory Chemical Management for Waste Reduction," available from the American Chemical Society's Department ofGovernment Regulations and Science Policy, 1155 16th Street N.W., Washington D.C. 20036, (202) 872-4477. 15.0

### WASTE MANAGEMENT 15.1 The Environmental Protection Agency requires that laboratory waste management practices be conducted consistent with all applicable rules and regulations. Excess reagents, samples and method process wastes should be characterized and disposed of in an acceptable manner. The Agency urges laboratories to protect the air, water, and land by minimizing and controlling all releases from hoods and bench operations, complying with the letter and spirit of any waste discharge permit and regulations, and hy complying with all solid and hazardous waste regulations, particularly the hazardous waste identification rules and land disposal restrictions. For further information on waste management consult lhe "Waste Management Manual for Laboratory Personnel," available from the American Chemical Society at the address listed in Sect. 14.3.

300.0-16

### 16.0 REFERENCES 1. 

### "Determination of Inorganic Disinfection By-Products by Ion Chromatography", J. Pfaff, 

### C. Brockhoff. J. 

### Am. Water Works Assoc., Vol BZ, 

### No. 4, pg 

### 192. 2. Standard Methods for the Examination nfWater and Wastewater, Method 4110B, "Anions by Ion Chromatography", 18th Ed1tion of Standard Methods (1992)

. 3. Dionex, System 4000 Operation and Maintenance Manual, Dionex Corp., Sunnyvale, California 94086, I988. 4

. Method Detection Limit (MDL) as described in "Trace Analyses for Wastewater,• 

### J. Glaser, D. Foerst, G. McKee, S. Quave, W. Budde, lnvironmental Science and Technology, Vol. 15, N umber 12, page 1426, December, 1981. 5. American Society for Testing and Materials. Test Method for Anions in Water by Chemicolly-SuppressPd Jon Chromatography D 4

327-91

. Annual Book ofStandards, V ol 11.01 (1993). 6. Code of Federal Regulations 40, Ch. 1, Pt. 136, Appendix B. 7. Hautman, D.P. 

### &Bolyard, M. Analysts ofOxyhalide Disinfection By- products and oth erAnions of Interest tn Drinking Waterby Ion Chromatograph y. Jour. ofChromatog., 602, (1992), 65-74.

300.0-17

### 17.0 TABLES. DIAGRAMS. FLOWCHARTS AND VALTDATION DATA
TABLE lA. CHROMATOGRAPHIC CONDITIONS AND DETECTION LIMITS 

### IN REAGENT WATER (PART A)
ANALYTE

Fluoride Chloride Nitrite-N Bromide Nitrate-N o-Phosphate-P Sulfate
Standard Conditions: 

### * RETENTION 

### PEAK I 

### TIHE(HIN)

1 2 3 4 5 6 7 1.2 1.7 

### 2.0 2.9 

### 3.2 5.4 6.9 

### MDL mg/L


### 0.01 0.02 0.004 0.01 0.002 0.003 0.02

Columns: as specified in 6.2.2.1 Delector: as specified in 6.2.4 Eluent: as specified in 7.3 Pump Rate: 2.0 mLjmin. Sample Loop: SO**~L** t1DL 

### calculated from data system using ay-axis selection of 1000 ns and with a stripchart recorder with an attenuator setting of I uMHO full scale. 

### * See Figure I

300.0-18

### TABLE lB. CHROMATOGRAPHIC CONDITIONS AND DETECTION LIMITS IN REAGENT WATER (PART B)

AHALYTE

Chlorite Bromate Chlorate
Standard Conditions: 

## * PEAK I

1 2 4

Column: as specified in 6.2.2.2 Detector: as specified in 6.2.4 Eluent: as specified in 7.3


### * See Figure 2 

### RETENTION TTME(MIN) MDL mg/L
2.8 3.2 7.1 0.01 0.02 0.003

**Pu~p** Rate: 1.0ml/min. Sample Loop: 50

**~L**

Attentuation

- 1 y-axis

- 500 n s

300.0-19TABLE 2A. SINGLE-OPERATOR ACCURACY AND BIAS Of STANDARD ANIONS (METHOD A}
KNOWN NUMBER MEAN STANDARD SAMPLE CONC. OF RECOVERY DEVIATION ANALYTE TYPE Cmg/Ll REPLICATES 

# " (p!q/ll Bromide RW 5.0 7 99 0.08 

## ow 5.0 7 lOS 0.10 

## sw 5.0 7 9S 0.13 

### ww 5.0 7 lOS 0.34 GW 5.0 7 92 0.34 

## so 2.0 7 82 0.06 Chloride RW 20.0 7 96 0.35 

## ow 20.0 7 108 1.19 

### SW 10.0 7 86 0.33 

## ww 20.0 7 101 5.2 

### GW 20.0 7 114 1.3 

## so 20.0 7 90 0.32 Fluoride RW 2.0 7 91 0.05 

## ow 1.0 7 92 0.06 SW 1.0 7 73 0.05 

### ww 1.0 7 87 0.07 GW 0.4 7 95 0.07 

### sn 5.0 7 101 0.35 Nitrate

- N RW 10.0 7 103 0.21 

## ow 10.0 7 104 0.27 SW 10.0 7 93 0.17 

## ww 10.0 7 101 0.82 GW 10.0 7 97 0.47 

## so 10.0 7 82 0.28 Nitrite

- N RW 10.0 7 97 0.14 

## ow 10.0 7 121 0.25 

## sw 5.0 7 92 0.14 

### ww 5.0 7 91 0.50 GW 10.0 7 96 0.3S 

## so 2.0 7 98 0.08

o Phosphate

- P RW 10.0 7 99 0.17 

## ow 10.0 7 99 0.26 

## sw 10.0 7 98 0.22 

### ww 10.0 7 106 0.85 GW 10.0 7 95 0.33

300.0-20

### Sulfate RW 

## ow 

## sw ww GW RW • Reagent Water OW

- Drinking Water SW • Surface Water T ABLE 2A (C O

NT'O)

20.0 50.0 40.0 40.0 40.0 7 7 7 7 7 

### 99 105

95 102 112 0.40 3.35 1.7 6.4 3.2 

### WW

**~** 

### Mixed Domestic and Industrial Wastew ater GW % 

### Groundwater SO% USEPA QC Solid (shale}

300.0

-21

### TABLE 2B. SINGLE-OPERATOR ACCURACY AND BIAS OF BY-PRODUCT (PART B) NUMBER MEAN STANDARD SAMPLE SPIKE OF RECOVERY DEVIATION ANALYTE TYPE (mg/L) REPLICATES % 

### (mgfL)
Bromate RW 5.0 7 103 0.07 1.0 7 98 0.04 0.1 7 155 0.005 0.05 7 122 0.01 

## ow 5.0 7 95 0.04 1.0 7 85 0.02 0.I 7 98 0.005 0.05 7 98 0.005 

### Chlorate RW 5.0 7 101 0.06 1.0 7 97 0.01 0.I 7 100 0.01 0.05 7 119 0.05 

### OW 5.0 7 101 0.04 1.0 7 115 0.01 0.1 7 121 0.005 0.05 7 110 0.01 

### Chlorite RW 5.0 7 100 0.04 1.0 7 98 0.01 0.1 7 86 0.01 0.05 7 94 0.01 

## ow 5.0 7 96 0.03 1.0 7 100 0.02 0.1 7 76 0.00 0.05 7 96 0.01 

### RW = 

### Reagent Water OW = 

### Drinking Water

300.0-22TABLE 3.

WATER M'T ADDED 1119/L Reagent 0.26 0.34 2.12 2.55 6.79 8.4 9 Drinking 0.26 0.34 2.12 2.55 6.79 S.49 Waste 0.26 0.34 2.12 2.55 6.79 8.49 **~LTIPLE** LABORATORY (n•l9) DETER"INATION OF BIAS FOR FLUORIDE

A"'T FOUND mg/L 

### st so BIAS 

# " 0.25 0.08 0.11 -3.8 0.29 0.11 -14.7 2.12 0.07 0.12 0.0 2.48 0.14 -2.7 6.76 0.20 0.19 -0.4 8.46 0.30 -0.4 0.24 0.08 0.05 -7.7 0.34 0.11 0.0 2.09 0.18 0.06 -1.4 2.55 0.16 0.0 6.84 0.54 0.25 +0.7 8.37 0.75 -1.4 0.25 0.15 0.06 -3.8 0.32 0.08 -5.9 2.13 0.22 0.15 +0.5 2.48 0.16 -2.7 6.65 0.41 0.20 -2.1 8.27 0.36 -2.6

300.0-23

### TABLE 4.

**~ULTIP LE**  

### L A

BORATORY (n•l9)

**DETER~INATION** 

### OF BIAS FOR CHLORIDE

WATER AI1'T ADDED Ari'TrOUN D 

### s, 

## s. BIAS mg/L mg/L 

# " Reagent 0.78 0.79 0.17 0.29 +1.3 1.04 1.12 0.46 +7.7 6.50 6.31 0.27 0.14 -2.9 7.80 7.76 0.39 -0.5 20.8 20.7 0.54 0.62 -0.5 26.0 25.9 0

.58 -0.4 

### Drinking 0.78 0.54 0.35 0.20 -30.8 1.04 0.51 0.38 -51.0 6.50 5.24 1.35 1.48 -19.4 7.80 6.02 1.90 -22.8 20.8 20.0 2.26 1.14 -3.8 26.0 24.0 2.65 -7.7 

### Waste 0.78 0.43 0

.32 0.39 -44.9 1.04 0.65 0.48 -37.5 6

.50 4.59 1.82 0.83 -29.4 7.80 5.45 2.02 -30.1 20.8 18.3 2.41 I.57 -II.8 26.0 23.0 2.50 -II.5

300.0-24

### TABLE 5. MULTIPLE L ABORATORY (ncl9) 

### DETERHINATJON OF BIA SFOR NITRITE

- NITROGE N

WAT ER AH'TADDED A"'T FOUND 

### s, 

## s. BIAS mg/L mg/L 

# " Reagent 0.36 0.37 0.04 0.04 -t2.8 0.48 0.48 0.06 0.0 3.00 3.18 0.12 0.06 16.0 3.60 3.83 0.12 +6.4 9.60 9.84 0.36 0.26 +2.5 12.0 12.1 0.27 +0.6 Drinking 0.36 0.30 0.13 0.03

-16.7 0.48 0.4 0 0.14

-16.7 3.00 3.02 0.23 0.12 +0.7 3.60 3.62 0.22

**~0.6** 9.60 9.59 0.44 0.28 0.1 12

## .o 11.6 0.59 3.1 

### Waste 0.36 0.34 0.06 0.04 5.6 0.48 0.46 0.07 4.2 3.00 3.10 0.13 0.10

**~6.0** 3.60 3.76 0.18 •4.4 9.60 9.74 0.49 0.26 +1.5 12.0 12.0 0.56 +0.3

300.0

-25

### TABLE 6. "ULTIPLE LABORATORY

**(n~l9)** 

### DETERMINATION OF BIAS FOR BROIIIDE

WATER A"'T ADDED AII'T FOUND 

### st s. mg/L mg/L Reagent 0.63 0.69 0.11 0.05 0.84 0.85 0.12 5.24 5.21 0.22 0.21 6.29 6.17 0.35 16.8 17.1 0.70 0.36 21.0 21.3 0.93 Drinking 0.63 0.63 0.13 0.04 0.84 0.81 0.13 5.24 5.11 0.23 0.J3 6.29 6.18 0.30 16.8 17.0 0.55 0.57 21.0 20.9 0.65 

### Waste 0.63 0.63 0.15 0.09 0.84 0.85 0.15 5.24 5.23 0.36 0.11 6.29 6.27 0.46 16.8 16.6 0.69 0.43 21.0 21.1 0.63

300.0-26 

### BIAS 

# " +9.5 +1.2 -0.6 -1.9 +1.6 +1.5

0.0 -3.6 -2.5 -1.7 +0.9 -0.4

0.0 +1.2 -0.2 -0.3 -1.0 +0.3TABLE 7.

**~LTJPLE** LABORATORY (n•l9} DETER"JNATION OF BIAS FOR NITRATE

- NITROGEN

WATER A"'T ADDEO APII'T FOUND 

## s, s. BIAS mg/l mg/L 

# " Reagent 0.42 0.42 0.04 0.02 0.0 0.56 0.56 0.06 0.0 3.51 3.34 0.15 0.08 -4.8 4.21 4.05 0.28 -3.8 11.2 11.1 0.47 0.34

-1.1 14.0 14.4 0.61 +2.6 Drinking 0.42 0.46 0.08 0.03 t9.5 0.56 0.58 0.09 +3.6 3.51 3.45 0.27 0.10

-1.7 4

.21 4.21 0.38 0.0 11.2 ll.5 0.50 0.48 + 2.3 14

.0 14.2 0.70 tl.6 Waste 0

.42 0.36 0.07 0.06

-14.6 0.56 0.40 0.16

-28.6 3.51 3.19 0.31 0.07

-9.1 4.21 3.84 0.28

-8.8 11.2 10.9 0.35 0.51

-3.0 14.0 14.1 0.74 + 0.4

300.0-27TABLE 8. MULTIPLE LABORATORY**(n ~19** **)** DETERMINATION OF BIAS FOR ORTHO-PHOSPHATE

WATER AM'T ADDEO AM'T FOUND 

## s, s. BIAS mg/L mg/L**~** Reagent 0

.69 0.69 0.06 0.06 0.0 0.92 0.98 0.15 +6.5 5.77 5.72 0.36 0.18 -0.9 6.92 6.78 0.42 -2.0 18

.4 18.8 1.04 0.63 +2.1 23.1 23.2 0.35 +0.4 Drinking 0

.69 0.70 0.17 0.17 +1.4 0.92 0.96 0.20 +4

.3 5

.77 5.43 0.52 0.40 -5.9 6.92 6.29 0.72 -9.1 18.4 18.0 0.68 0.59 -2.2 23.1 22.6 1.07 -2.0 Waste 0.68 0.64 0.26 0.09 -7.2 0.92 0.82 0.28 -10.9 5.77 5.18 0.66 0.34 -10.2 6.92 6.24 0.74 -9.8 18.4 17.6 2.08 1.27 -4

.1 23.1 22.4 0.87 -3.0

300.0-28

### TABLE 9. MULTIPLE LABORATORY (nel9) 

### DETERMINATION OF BIAS FOR SULFATE

WATER AM'T ADDED AM'T FOUND 

## s, mgfl mg/L Reagent 2.85 2.83 0.32 3.80 3.83 0.92 23.8 24.0 1.67 28.5 28.5 1.56 76.0 76.8 3.42 95.0 95.7 3.59 Drinking 2.85 1.12 0.37 3.80 2.26 0.97 23.8 21.8 1.26 28.5 25.9 2.48 76.0 74.5 4.63 95.0 92.3 5.19 Waste 2.85 1.89 0.37 3.80 2.10 l.25 23.8 20.3 3.19 28.5 24.5 3.24 76.0 71.4 5.65 95.0 90.3 6.80

300.0-29 

## so BIAS % 0.52

-0.7 +0.8 0.68 +0.8 -0.1 2.33 +1.1 +0.7 0.41 -60.7 -40

.3 0.51 -8.4 -9

.I 2.70 -2.0 -2.8 0.24 -33.7 -44.7 0.58 -14.7 -14.0 3.39 -6.] -5.0

# MethodA

Peak 1 2 3 

## 2 4 5 6 7 

### 7 5

1 

### 3 

# ll 4 

### \. 6 

## I I I I 

## I 0 2 4 6 8 Minutes Figure1

.Clv'omatogramShow1ngseparallonusingtheAS4AeolurM



### I 0 I 

### I 2 

### 1 2

### 3



### I 4 Minutes 

# MethodB

Peak 1 2 3 4



### 4



### I 

### I 6 8 Figure2

.ChromatogramshowingseparationuSinglheA S9cotumn R et.T ime lon mg/L 1.17 F- 2 1.73 Cl" 20 2

.02 NO- 2 I 2

.95 

### Br 2 3.20 NO

- l 10 5

.38 HPO

### >- 

## • 2 8.92 

### so>- 

## • 60

Ret.Time I 

### on mg /L 2

.75 CIO2 0

.1 3

.23 BrO

- ) 0

.1 3

.63 Cl" 0.1 7.08 CIO- 3 0

.1