METHOD 552.3 DETERMINA TION OF HALOA CETIC ACID S AND DALA PON IN DRINKING WATER BY LIQUID-LIQUID MICROEXTRACTION, DERIVATIZ ATION, AN D GAS CHROM ATOGRAPHY WITH ELECTRON CA PTURE DETEC TION

EPA 815-B-03-002

Revision 1.0

July 2003

M. M. Domino and B.V. Pepich (Shaw Environmental and Infrastructure, Inc .) D.J. Munch and P.S. Fair (US EPA, Office of Ground Water and D rinking Water) Y. Xie (Penn State University)

D.J. Munc h, J.W. Mu nch (US EP A, Offic e of Gro und Wate r and Dr inking Wa ter) an d A. M. Paw leckiVonderheide (ICI) Method 552.2, Revision 1.0 (1995) J.W. Hodgeson (USEPA), D. Becker (Technology Applications, Inc .) Method 552.1, (1992) J.W. Hodgeson (USEPA), J. Collins and R. E. Barth (Technology Applications, Inc.) Method 552.0, (1990)

TECHNICAL S UPPORT CEN TER OFFICE OF GR OUND WATER AND DRIN KING WATER U. S. ENVIRONMENTAL PROTECTION AGENCY CINCINNATI, OHIO 45268

552.3-1METHOD 552.3
DETERMINA TION OF HALOA CETIC ACID S AND DALA PON IN DRI NKING WATER BY LIQUID-LIQUID MICROEXTRACTION, DERIVATIZATION, AND GAS CHROMATOG RAPHY WITH ELECTRON CA PTURE DETEC TION

1. SCOPE AND A PPLICATION
1.1 This is a gas chromatography (GC) method for the determination of haloa cetic acids and dalapon in drinking waters. Accuracy, prec ision, and Detection Limit (DL) data are presented for the following compounds in reagent water and finished ground and surface waters.

Analyte
Bromochloroacetic acid (BCAA) Bromodichloroacetic acid (BDCAA) Chlorodibromoacetic acid (CDBAA) Dalapon Dibromoacetic acid (DBAA) Dichloroacetic acid (DCAA) Monobromoacetic acid (MBAA) Monochloroacetic acid (MCAA) Tribromoacetic acid (TBAA) Trichloroacetic acid (TCAA) Chemical Abstracts Service (CAS) Registry Number 5589-96-8 71133-14-7 5278-95-5

75-99-0 631-64-1 79-43-6 79-08-3 79-11-8 75-96-7 76-03-9
1.2 Detection Limits are compound, instrument, and matrix dependent. The DL is defined a s the statistically calculated minimum amount that can be measured with 99% confidence that the reported value is greater than ze ro. (1) Detection Limits for the above listed analytes are provided in Section 17, Table 5. The DL diffe rs from, and is lower than, the Minimum Reporting Level (MRL) (Sect. 3.17). The concentration range for target

552.3-2analytes in this method was evaluated between 0.5 μg/L and 30 μg/L for a 40-mL sample. Precision and accuracy data ar e presented in Section 17, Tables 6-11.
1.3 This method is restricted to use by or under the supervision of analysts skilled in liquidliquid extr actions, derivat ization p rocedur es and the use of GC a nd interp retation of gas chromat ograms.

2. SUMMARY OF METHOD
2.1 A 40-mL volume of sample is adjusted to a pH of 0.5 or less and extracted with 4 mL of e ither methyl tert-butyl ether (MTBE) or tert-amyl methyl ether (TAME) c ontaining an internal standard. The haloacetic acids that have be en partitioned into the organic phase are then converted to their methyl esters by the addition of acidic methanol followed by hea ting for 2 hours. The solvent phase co ntaining th e methyla ted haloa cetic a cids is sep arated from the a cidic methanol by adding 7 mL of a concentrated aqueous solution of sodium sulfate. The a queous phase is discarded. The extract is then neutralize d with a saturated solution of sodium bicarbonate and the solvent layer is removed for a nalysis. The target analytes are identified and quantified by capillary column gas chromatography using an elec tron capture detector (GC/ECD). Analytes are quantified using procedural standa rd calibration.

3. DEFINITIONS
3.1 EXTRACTION BATCH – A set of up to 20 Field Samples (not including calibration standards and QC samples) extracted together by the sa me person(s) during a work day using the same lots of solvents, surrogate solution, and fortifying solutions. Required QC samples include a L aborato ry Reage nt Blank, L aborato ry Fortifi ed Matrix , either a Field Duplicate or Laboratory Fortified Matrix Duplicate and a n appropriate number of Continuing C alibrati on Checks

. 3.2 ANALYSIS BATCH – A set of samples that is analyzed on the same instrument during a 24-hour period that begins and ends with the analysis of the appropriate Continuing Calibration Check standards (CCC). Additional CCCs may be required depending on the length of the anal ysis batc h and/or t he number of Field Sa mples.

552.3-33.3 INTERNAL STANDARD (IS) – A pure analyte adde d to an extract or standard solution in a known amount and used to measure the relative responses of other method analytes and surr ogates. T he inter nal stand ard must b e an ana lyte that i s not a sam ple compo nent.
3.4 SURROGATE ANALYTE (SUR) – A pure analyte, which chemica lly resembles target analytes and is extremely unlikely to be found in any sample. This analyte is added to a sample aliquot in a known amount before extraction or other proc essing, and is measured with the same procedures used to measure other sa mple components. The purpose of the SUR is to monitor method performance with each sample.
3.5 LABORATORY REAGENT BLANK (LRB) – An aliquot of reagent water or other blank matrix that is treated exactly as a sample including exposure to all glasswar e, equipment, solvents, reagents, sample preservatives, internal standar ds, and surrogates that are used in the extraction batch. The LRB is used to determine if method ana lytes or other interferences are pr esent in the laboratory environment, the reagents, or the appara tus.
3.6 LABORATORY FORTIFIED BLANK (LFB) – An aliquot of reagent water or other blank matrix to which known quantities of the method analytes and all the preservation compound s are ad ded. The LFB is anal yzed ex actly like a sample , and its pu rpose is to determine whether the methodology is in control, and whether the labora tory is capable of making ac curate and prec ise measu rements.
3.7 LABORATO RY FORTIFI ED SAMPLE M ATRIX (L FSM) – An al iquot of a Field Sample to which known quantities of the method analytes and all the preservation compounds are added. The LFSM is processed and analyze d exactly like a sample, and its purpose is to determine whether the sample matrix contributes bias to the analytical results. The background concentrations of the ana lytes in the sample matrix must be determined in a separate aliquot and the measure d values in the LFSM corrected for backgro und conc entratio ns.
3.8 LABORATORY FORTIFIED SAMPLE MATRIX DUPLICATE (LFSMD) – A second aliquot of the Field Sample used to prepare the LFSM which is fortified, extracted and analyze d identic ally to the LFSM. The L FSMD is used instead o f the Field Duplicat e to access method pr ecision a nd accu racy when the oc currence of a t arget a nalyte is infrequ ent.

552.3-43.9 LABORATO RY DUPLICA TES (LD1 a nd LD2) – T wo aliquo ts of the sa me sample split in the laboratory and analyzed separa tely with identical procedures. Analyses of LD1 and LD2 indic ate pre cision as sociate d with labo ratory p rocedur es, but not with sampl e collecti on, prese rvation, and stora ge proce dures.
3.10 FIELD DU PLICATES ( FD1 and FD2 ) – Two se parate samples c ollected at the sa me time and place under identical circumstances, a nd treated exactly the same throughout field and laboratory procedures. Analyses of FD1 and FD2 give a measure of the precisio n associa ted with sa mple colle ction, pr eserva tion, and s torage, as well a s with laborat ory proc edures.
3.11 STOCK STANDARD SOLUTION (SSS) – A concentrated solution containing one or more method analytes prepared in the laboratory using assa yed reference materia ls or purchased from a reputable commerc ial source.
3.12 PRIMARY DILUTION STANDARD (PDS) SOLUTION – A solution containing method analytes prepared in the laboratory from stock standa rd solutions and diluted as needed to prepa re calib ration so lutions an d other ne eded an alyte solu tions.
3.13 CALIBRATION STANDARD (CAL) – A solution prepared from the primar y dilution standar d solution a nd/or stoc k standar d solutions and the in ternal st andardsand surr ogate analyte s. The CAL solutions a re used t o calibr ate the in strument r esponse w ith respe ct to analyte concentration.
3.14 CONTINUING CALIBRATION CHECK (CCC) – A calibration standard conta ining the method an alytes, in ternal st andard( s) and sur rogate( s), which is analyz ed perio dically to verify the accuracy of the e xisting calibration for those analytes.
3.15 QUALITY CONTROL SAMPLE (QCS) –A sample prepared using a PDS of method analytes that is obtained from a source external to the labor atory and different from the source of calibration standards. The second sourc e PDS and the surrogate PDS are used to fortify the QCS at a known concentration. The QCS is used to check calibra tion standard integrity.
3.16 DETECTION LIMIT – The minimum concentration of an analyte tha t can be identified, measured and reported with 99% confidenc e that the analyte concentration is greater tha n zero (Sect. 9.2.4). This is a statistical determination of precision. Accur ate quantitation is not expe cted at th is level. (1)
552.3-53.17 MINIMUM REPORTING LEVEL (MRL) – The minimum concentration that can be reporte d as a qua ntified va lue for a target a nalyte in a sample following analysis

. This defined concentration can be no lower tha n the concentration of the lowest continuing calibration standard for that analyte, and can only be used if acceptable quality control criteri a for this standar d are me t.
3.18 PROCEDURAL STANDARD CALIBRATION – A calibration method in which aqueous calibration standards are prepa red and processed (e.g., extrac ted, and/or derivatized) in exactly the same manner a s the samples. All steps in the process from addition of sampling preservatives through instrumental analyses are included in the calibra tion. Using procedu ral stand ard cal ibration c ompensat es for a ny ineff iciencie s in the processing procedure.
3.19 MATERIAL SAFETY DATA SHEET (MSDS) – Written information provided by vendors concerning a chemical’s toxicity, health haz ards, physical properties, fire, and reactiv ity data including st orage, s pill, and h andling pr ecautio ns.

4. INTERFEREN CES

4.1 All glassware must be meticulously cleaned. Wash glassware w ith detergent and tap water, rinse with tap water followed by rea gent water. A final rinse with solvents may be needed. In place of a solvent rinse, non-volumetric gla ssware can be muffled at 400 °C for 2 hours. Volumetric glassware should not be heated in an oven a bove 120 °C. Store glasswar e invert ed or ca pped with aluminum f oil.
4.2 Method interferences may be cause d by contaminants in solvents, reagents (including reagent water), sample bottles and caps, a nd other sample processing hardware that lead to discrete artifacts and/or elevated base lines in the chromatograms. All items used in the method must be routinely demonstrated to be free from interfere nces (less than 1 / 3 the MRL for each target) under method conditions by processing and a nalyzing laboratory reagent blanks as described in Section 9. Subtract ing blank value s from sa mple results is not permitted.
4.2.1 Sodium sulfate can be a source of method interfere nces. After screening severa l brands, it was found that a grade suitable for pesticide re sidue analysis had the lowest amount of method interferants. If the suitability of the available sodium
552.3-6sulfate i s in questio n, extra ct and an alyze a laborat ory rea gent blan k (Sect. 3 .5) to test for interferences prior to sample proce ssing.
4.2.2 The ester of bromochloroacetic ac id (BCAA) coelutes with a low-level interferant on both the primary and confirmation column. This interferant is present in the LRB and believed to be dimethyl sulfide that originates in the sodium sulfate. Because of difference in pea k shape, the BCAA ester tends to “ride on” the interferant allowing accurate quantitation. Concentra tions of BCAA at or below 2 : g/L may require manual integration of the BCAA.
4.2.3 TAME, which has higher methylation efficiencies for the triha loacetic acids than MTBE , is curr ently only availab le at 97% purity. Di ffere nt lots of T AME should be carefully evaluated for potential interf erants. Several lots of TAME contained an interferant that coeluted with the ester of monochloroa cetic acid (MCAA) on the primary column.
4.3 The esters of the surrogate used in Method 552.2 (2,3-dibromopropa noic acid) and dichloro bromoac etic ac id are no t complete ly resolv ed under the chro matogra phic conditions for the confirmation column listed in Tables 3 and 4. The current surroga te, 2-bromobutanoic acid, is fully resolved from all method compounds on both columns under the conditions listed in Tables 1-4 (Figs. 1-4).
4.4 Matrix interferences may be cause d by contaminants that are extracted from the sample. The extent of matrix interferences will vary c onsiderably from source to source, depending upon the water sampled.
4.5 Interferences by phthalate ester s can pose a major problem in analysis when using an electron capture detector (ECD). T hese compounds generally appear in the chroma togram as large peaks. Common flexible plastics contain varying amounts of phthalates that are easily extracted or leached during labora tory operations. Cross contamination of clean glasswar e routine ly occur s when pla stics are handled d uring ext raction steps, es pecially when solvent-wetted surfaces are ha ndled. Interferences from phthalates c an best be minimized by avoiding the use of plastics in the laboratory. Exhaustive purification of reagen ts and gla ssware m ay be re quired to eliminate backgro und phtha late contamination. (2,3)

552.3-75. SAFETY
5.1 The toxic ity or ca rcinoge nicity of e ach rea gent used in this meth od has not b een pre cisely defined. Each chemical compound should be treate d as a potential health hazard, and exposure to these chemicals should be minimized. The laboratory is responsible for maintaining a current awareness file of OSHA r egulations regarding the safe handling of the chemicals specified in this method. A reference file of MSDSs should also be made availab le to all pe rsonnel i nvolved in the chem ical ana lysis. Addi tional referenc es to laboratory safety are available. (4-6)
5.2 Pure stan dard mat erials a nd stock st andards of these compound s should be handled w ith suitable protection to skin and eyes, and care should be taken not to brea the the vapors or ingest the materia ls.
5.3 The toxicities of the extraction solvents, MTBE or TAME, have not been well define d. Susceptible individuals may experience adverse eff ects upon skin contact or inhalation of vapors. T herefo re prote ctive clo thing and g loves should be used and MTBE o r TAME should be used only in a chemical fume hood or glove box. The same prec aution applies to pure st andard m aterial s.

6. EQUIPMENT AND SUPPL IES
6.1 SAMPLE CONT AINERS – A mber gla ss bottles, at least 5 0-mL, fitt ed with PTFE (polytetr afluoro ethylene ) lined sc rew ca ps.
6.2 EXTRACTI ON VIAL S – 60-mL c lear gla ss vials wi th PTFE-line d screw caps.
6.3 AUTOSAMPLER VIALS – 2.0-mL amber vials with screw or crimp cap and aPTFEfaced s eal.
6.4 STANDARD SOLUTIO N STORAGE CONTAIN ERS – 10- to 2 0-mL ambe r glass via ls with PTFE-l ined scr ew caps . 6.5 GRADUATED CONICAL CENTRIFUGE TUBES WITH PTFE-LINED SCREW CAPS – 15-mL with graduated 1-mL markings (Fisher Cat. #: 05-538-30A or equivalent).

552.3-86.6 PASTEUR PIPETTES – Glass, disposable.

6.7 PIPETTES – C lass A, 2. 0-, 3.0-, 4.0-, an d 7.0-mL g lass, or a djustable volume dis pensers . 6.8 VOLUMETRIC FLASKS – Class A, suggested sizes include 5-mL, 10-mL, 100-mL.
6.9 MICRO SYRIN GES – Var ious size s.
6.10 HEATER (BLOCK,or SAND BATH or WATER BATH) – A block heater (Thermolyne Model DB16525, Fisher Cat. #: 11-716-50 or equivalent) capable of maintaining regulated, elevated temperature e quipped with a sand bath or heating block (Fisher Cat. #: 11-716-27 or equivalent) capable of holding screw cap conical centrifuge tubes in Section 6.5 was used for method development. A thermostated water ba th equipped with a surface layer of small plastic spheres (Fisher Cat. #. 14-220- 31 or equivalent) to retard evaporation and subsequent heating of tube walls may also be used.
6.11 pH PAPER - With a pH range of 0 - 1.5 (Fisher Cat. #. 14-853-55 or equivalent).
6.12 BALANCE – Analytical, capable of weighing to the neare st 0.0001 g.
6.13 VORTEXER – Used to mix sample extracts (VWR Vortex-Genie, Cat. #:14216-184 or equivalent).
6.14 GAS CHROMATOGRAPH – Capillary GC, with a low volume (150 μ L) micro ECD (Agilent Model 6890 or equiva lent). Th e injecto r system sh ould not al low analy tes to contact hot stainless steel or other metal surfaces that promote dec omposition. The perfor mance da ta in Sect ion 17 was collecte d using hot, splitless in jection u sing a 2-m m i.d. quartz liner. Other injection techniques such as temperatur e programmed injection, cold on-column injection, and large volume injection may be used if the QC criteria of Sections 9 and 10 are met. Alternate detectors which ha ve equivalent or greater selectivity for the target compounds may be used.
6.15 AUTOSAMPL ER – Agilen t Model 768 3 or equiv alent.
6.16 PRIMARY GC C OLUMN – D B-1701, 30 -meter l ength, 0. 25-mm i.d. , 0.25-μm f ilm, fused silica capillary with chemically bonded (14% cyanopropylphenyl-methylpolysiloxane), or equivalent bonded, fused silica column.

552.3-96.17 CONFIRMAT ION GC COL UMN – DB-5 .625, 30- meter le ngth, 0.25 -mm i.d., 0 .25-μm film, fuse d silica c apillary with chem ically bo nded (“e quivalen t to” 5% phenylmethylpolysiloxane), or equivalent bonded, fused silica column.

7. REAGENTS AND STANDARDS
7.1 REAGENTS AND SOLVENTS – Rea gent gra de or bet ter che micals sho uld be use d in all analy ses. Unle ss otherw ise indica ted, it is in tended th at all re agents sh all conf orm to the specifications of the Committee on Analytical Reagents of the American Che mical Society, w here suc h specif ications a re avai lable. Ot her gra des may be used, pro vided it is first determined that the reagent is of sufficiently high purity to permit its use without lessening the quality of the determination.
7.1.1 REAGENT W ATER – Puri fied wat er which does not c ontain an y measur able quantities of any target analytes or interfering compounds gre ater than 1/3 the MRL for each compound of interest.
7.1.2 METHYL tert-BUTYL ETHER (MTBE) – High purity, demonstrated to be free from analytes and interferences ( HPLC grade or better).
7.1.3 Tert-AMYL METHYL ETHER (TAME) – High purity, demonstrated to be f ree from analytes and interferences.
7.1.3.1 Currentl y, TAME is a vailable in > 97% pu rity. Seve ral manu factur ers’ products were e valuate d and fou nd to conta in a compound that elutes with MCAA on the primary column. Lots evaluated from Fluka (Riedel-de Haen), stored ov er molecular siev es, wer e free from this i nterfe rant.
7.1.4 SODIUM SULFATE, Na 2 SO 4 – Pesticide grade, granular, anhydrous. Interferences have bee n observed when lower quality grades have be en used. If interferences are observe d, it may be necessary to heat the sodium sulfate in a shallow tray at 400 °C for up to 4 hr to remove phthalates and other interfe ring organic substances. Store in a capped glass bottle rather tha n a plastic container.
7.1.5 SODIUM BI CARBONATE , NaHCO 3 – ACS reagent grade.
7.1.6 AMMONIUM CHLORIDE, NH 4 Cl – ACS reagent grade.
552.3-107.1.7 SULFURIC ACID – Concentrated, ACS reagent grade. Substitution of hydrochloric acid (HCl) is not allowed. Solutions of HCl can contain trace levels of bromide, w hich can pro mote the format ion of brom inated HAA s.
7.1.8 HELIUM ( or HYDRO GEN)– 99 .999% pur e or bett er, GC ca rrier ga s.
7.1.9 ARGON 95% /METHANE 5% (or NI TROGEN) – 99.999% pure or b etter, E CD make-up gas.
7.1.10 SODIUM SULFATE SOLUTION – Prepare an aqueous solution of sodium sulfate in reagent water at a conc entration of 150 g/L. Substitutio n of sodium chloride is not allowed. Sodium chloride can contain trace levels of bromide, which can pr omote t he forma tion of bro minated HA As.
7.1.11 SODIUM BICARBONATE SOLUTION, SATURATED – Add sodium bicarbo nate to a volume of water, m ixing per iodically until the so lution has a small amount of undissolved sodium bicarbonate that does not disappear upon further mixing.
7.1.12 10% SULFUR IC ACID I N METHAN OL SOLUTI ON – Add 10 mL of sulf uric acid dropwise (due to heat evolution) to 50-60 mL of methanol contained in a 100-mL vo lumetric flask tha t has bee n placed in a cooli ng bath. Mi x, let coo l, and dilute to the 100-mL mark with methanol.
7.2 STANDARD SOLUTIONS – Standard Solutions may be prepared from cer tified, commercially available solutions or from neat compounds. When prepa ring from neat materia l, compoun d purity ne eds to be 9 6% or gre ater. W hen a co mpound pur ity is assayed to be 96% or greater, the we ight can be used without correction to calculate the concentration of the stock standard. Solution concentrations listed in this section were used to de velop this method an d are inc luded as a n example

. Standar ds for sa mple fortific ation gen erally sh ould be pr epared in the smal lest volume that can be accu rately measured to minimize the addition of organic solvent to aqueous samples. Laboratories should use standar d QC proce dures to d etermine when Stan dard Solut ions desc ribed in this section need to be replaced.
7.2.1 STANDARD PREPARATION AND STORAGE TECHNIQUES – All Standard Solutions are prepared from either neat or solid materia ls following the general procedure outlined below. This procedure assumes that the sta ndard stock
552.3-11solutions are prepared in 10-mL volumetric flasks. The proce dure should be scaled a ccordin gly if lar ger volum etric fl asks are used. Most standar ds in this method are made up in MTBE, whether the extracting solvent is MTBE or TAME. This is because MTBE is more water-soluble than TAME.
7.2.1.1 For analytes which are solids in their pure form, prepare stock standard solutions by accurately weighing the suggested amount (refer to the sections below for suggested weights) of pure material into a cle an, tared 10-mL volu metric f lask. Dilu te the fla sk to volume with MTBE a nd mix thoroughly.
7.2.1.2 For analytes which are liquid in their pure form at room temperatur e, place about 9.8 mL of MTBE i nto a 10-m L volumetr ic flask. Allow the flask to stand, uns toppere d, for ab out 10 minut es to allow solvent f ilm to evap orate from the inner walls of the volumetric, and weigh to the neare st 0.1 mg. Using a 10-μL (or gastight) syringe add the desired volume of the neat standard material to the flask by keeping the syringe needle just above the surfac e of the M TBE. Be sur e that the standar d materia l falls dr opwise directly into the MTBE without contacting the inner wall of the volumetric. Record the weight and calculate the conc entration of the stock standar d from the net gain i n weight. Dilute to v olume, sto pper, the n mix by invert ing the fla sk sever al times.
7.2.1.3 Transfe r the stoc k solutions to amber glass via ls or ambe r bottles w ith PTFE-line d caps an d store a t # 0 °C.
7.2.2 INTERNA L STANDAR D (IS) SOL UTIONS – 1 ,2,3-tri chloropr opane (9 9+%) is used as an internal standard for the method. This compound has bee n shown to be an effective internal standard for the method analytes, but other compounds may be used if the QC re quireme nts in Sect ion 9 are met.
7.2.2.1 INTERNAL STANDARD STOCK SOLUTION (2.0 mg/mL) – Prepare an internal standard stock solution by accurately transfer ring approximately 0.0200 g of neat 1,2,3-trichloropropane (we ighed to the nearest 0.1mg) into a 10-mL volumetric flask containing methanol as described in Section 7.2.1. The resulting concentration of the stock internal standard solution will be approximately 2.0 mg/mL.

552.3-127.2.2.2 INTERNA L STANDAR D PRIMARY D ILUTIO N STANDA RD (100μg/mL) – Prepare an internal standard fortification solution at 100μg/mL (or other suitable concentration) by the addition of 500 μL (or other ap propria te volume ) of the s tock stan dard to a 10-mL volu metric flask co ntaining M TBE. Dilute to volume, mix thorou ghly and tr ansfer to an amber glass via l with a PTFE -lined sc rew ca p and stor e at # 0°C.
7.2.2.3 MTBE (or TAME) EXTRACTION SOLVENT WITH INTERNAL STANDARD (1.00 μg/mL) – The internal standard 1,2,3-trichloropropane is added t o the extr action so lvent prio r to anal yte extr action to compensa te for any volumetric differences enc ountered during sample processing. Have en ough work ing solven t availab le to extr act all c alibrati on standa rds, QC samples and field samples in each extraction batch. The volume of fortifie d solvent s hould be d etermine d by the sa mple work load. Ne ver use two different lots of working solvent for one extraction batch. The following example illustrates preparation of 100 mL of fortified solvent. Add 1 mL of the prima ry dilution standar d (100 μg/mL) to a 100- mL volumetri c flask c ontaining MTBE (or T AME), dilu te to volume and mix thoroughl y. Trans fer the standar d to an amb er bottle for stora ge. This results in a final in ternal st andard c oncentr ation of 1 .00 μg/mL. T his solution is used to extract the samples (Sect. 11.1).
7.2.3 SURROGATE (SUR) ANALYTE STANDARD SOLUTION – 2-bromobutanoic acid (99+%) is used as a surrogate compound in this method to evaluate the extraction and derivatization procedures. This compound ha s been shown to be an effective surrogate for the me thod analytes and is well resolved from all target analytes and common interferants on both chromatographic c olumns. The Method 552.2 surrogate, 2,3-dibromopropanoic acid, can be use d with this method, but requires a longer chromatographic run to sepa rate it from DCBAA (Sect. 4.3). Other SUR analytes may be used as long as they are halogena ted carboxylic acids and the QC requirements of Section 9.7 are met. All surrogates must be adde d as free a cids. Alte rnate c andidate s should be confirme d to have a dequate esterification efficiencies (e.g. $ 80%) by c ompariso n to a comm erciall y availa ble premethylated standard. Lower esterifica tion efficiencies may lead to poor SUR precision.
Note: 2-b romo-2- methylpro panoic a cid was r uled out a s a potent ial SUR bec ause it was found to degrade in the Field and QC Samples if they were not processe d
552.3-13immediately. Nearly 50% of the fortified concentra tion was lost when samples were fo rtified a nd then al lowed to se t for 3 hou rs prior t o acidif ication. Alterna te surrogate compounds MUST be carefully evaluated.
7.2.3.1 SURROGATE STOCK SOLU TION (10 mg/mL) – Pr epare s urrogat e stock sta ndard sol utions of 2 -bromobu tanoic a cid [80- 58-0] by a ccurat ely transferring approximately 0.100 g of the neat materia l (weighed to the
neares t 0.1 mg.) i nto a cle an, tare d 10-mL vo lumetric flask as describ ed in Section 7.2.1. The resulting concentration of the Surrogate Stock Solution will be approximately 10 mg/mL.
7.2.3.2 SURROGATE PRIMARY DILUTION STANDARD (20 μg/mL) – Prepare a primar y dilution st andard ( PDS) at a c oncentr ation of 2 0 μg/mL (or other suitable concentration) by adding 50 μL (or suitable volume) of the SUR stock standard to a 25-mL volumetric flask containing MTBE. Dilute the flask to v olume, an d mix thoro ughly. Tr ansfer the SUR PDS to an amber glass via l with a PTFE -lined sc rew ca p and stor e at # 0 °C. Addition of 20 μL of the primary dilution standard to the 40-mL aqueous sample results in a surrogate concentration of 10 ng/mL.
7.2.4 ANALYTE STANDARD SOLUTIO NS – Obtain the anal ytes liste d in the ta ble in Section 1.1 as neat or solid free acid standards or as c ommercially prepared ampulized solutions from a reputable standard manufacture r. The use of premeth ylated sta ndards is not allowe d for the prepar ation of a nalyte sta ndards. Prepare the Analyte Stock and Primary Dilution Standards as described be low.
7.2.4.1 ANALYTE STOCK SOLUTION – Prepare separ ate stock standard solutions f or each analyte of intere st at a co ncentra tion of 1- 5 mg/mL in MTBE. Method analytes are available as neat mater ials or ampulized solutions (> 99% purity) from a number of commercial suppliers.
7.2.4.1.1 For analytes which are solids in their pure form, prepare stock standard solutions by accurately weighing approximately 0.01 to 0.05 gra ms of pure materia l in a 10-mL volumetri c flask using the technique described in Section 7.2.1.1.

552.3-147.2.4.1.2 For analytes which are liquid in their pure form at room temperature, add 10.0 μL of standard material to the flask using the technique described in Section 7.2.1.2.
7.2.4.2 ANALYTE PRIMARY DILUTION STANDARD (PDS)– Prepare the Analyte PDS solution by combining and diluting the Analyte Stock Solutions pr epared above (S ect. 7.2. 4.1) with M TBE. This so lution will be used to prepar e the Ana lyte Seco ndary Di lution Stan dard. As a guideline to the analyst, the concentration used in the primary dilution standard solution during method development was 100 μg/mL for all ten analytes.
7.2.4.3A NALYTE SECONDARY D ILUTIO N STANDA RD (SDS)– T he Analyte SDS is used to fortify reagent water for calibration standar ds. Prepare at least one Analyte SDS by diluting the Analyte PDS with methanol. Two Analyte SDSs were used during method development. The first was prepar ed at a c oncentr ation of 5 .00 μg/mL (1 /20 dilution of the An alyte PDS) and the second at a concentration of 16.7 μg/L (1/6 dilution of the Analyte PDS). The SDS should be made daily. It should not be stored, since me thanol wil l deriva tize the a cids that i t contain s. The low est calibration standard concentration must be at or below the MRL of e ach analyte. The concentrations of the other standar ds should span the range of concentration expected in the Field Samples or the working range of the instrumen t.
7.2.5 CALIBRATI ON STAND ARDS – At le ast 5 cal ibration s tandard s are re quired to prepare the initial calibration curve (Sect. 10.2). Fortify a n appropriate number of reagent water solutions with varying amounts of the Analyte PDS over the concentration range of interest. During method deve lopment, the Calibration Standard s typicall y ranged from 1.0 μg /L to 20 μg/L

. The lowe st standa rd must be at or b elow the M RL, which will depe nd upon ins trument se nsitivity. Because this method employs a procedural calibration technique , these standar ds must be treated like samples and require the addition of all prese rvation and other reagents. They are extracte d by the procedure described in Section 11.

552.3-158. SAMPLE COLLE CTION, PRE SERVATION, AND STORAG E
8.1 SAMPLE BOTTLE PREPARATION
8.1.1 Grab samples must be collected in accordance with conventional sampling practices (7) using amber glass containers with PTFE-lined screw caps and capacities of at least 50 mL.
8.1.2 Prior to shipment to the field, add crystalline or granular ammonium chloride (NH 4 Cl) to the sample containers to produce a concentration of 100 mg/L in the Field Sample. For a typical 50-mL sample, this requires 5 mg of ammonium chloride. Note: Enough ammonium chloride must be added to the sample to convert the free c hlorine r esidual in the sample matrix to c ombined c hlorine. Chloramin es, formed by the reaction of hypochlorite with the ammonium ion, do not react further to produce additional haloacetic ac ids at significant concentrations and protect against microbiological degradation. (8) This concentration of ammonium chloride was determined to convert 8 mg/L of free chlorine residual to combined chlorine.
8.2. SAMPLE COLLECTION
8.2.1 Fill sample bottles bu t take ca re not to f lush out the ammonium c hloride. Because the target analytes of this method are not volatile, it is not necessary to ensure that the sample bottles are completely headspace fr ee.
8.2.2 When sampling from a water tap, remove the ae rator. Open the tap and allow the system to flush until the water temperature has stabilized (usually about 3-5 minutes). Collect sa mples fro m the flow ing system.
8.2.3 When sampling from an open body of water, fill a 1-quar t wide-mouth bottle or 1 liter be aker wit h sample f rom a re present ative ar ea, and caref ully fill sa mple vials from the container.
8.2.4 After c ollecting the sample , seal the bottle an d agitate by hand f or 15 sec onds.

552.3-168.3 SAMPLE SHIPMENT AND STORAGE – All samples must be chilled during shipment and must not exceed 10 °C during the first 48 hours after collection. Samples must be confirmed to be at or below 10 °C when they are re ceived at the laboratory. Samples stored in the lab must be held at or below 6 °C and protected from light until extraction. Samples should not be frozen.
8.4 SAMPLE AND EXTRACT HOLDING TIMES – Chlorinated Field Samples that are preserved according to the method should not exhibit biological degradation of ana lytes during the allotted 1 4-day sto rage time . Samples m ust be ext racted within 14 da ys. Unchlorinated Field Samples should be extracted as soon as possible to prevent biologica l degrad ation of a nalytes. Extract s must be sto red at # -10 °C or less and protected from light in glass vials with PTFE-lined caps. MTBE extracts must be analyzed within 21 days of extraction. TAME extracts must be ana lyzed within 28 days of extraction.
8.4.1 The brominated trihaloacetic acids can exhibit degra dation during storage. Tribromo acetic acid (TB AA), the least sta ble HAA e ster, is de graded t o bromoform. This is thought to occur as a result of peroxide contamination in the solvent. Low concentrations of peroxides that were ba rely detectable with the commercially available peroxide test strips were found to ge nerate significant levels of bromoform in standard solutions. Bromoform can be chromatographed under method conditions (see Tables 1-4), and can be monitored as an indication of high pe roxide le vels in the solvent. I f large bromofor m peaks a re obser ved in HAA-fortified reagent water sa mples (or calibration standards), the ether solvent should be purified or replaced. Storing these solvents under nitrogen minimizes peroxide formation.
8.4.2 Extracts that were prepared using the TAME pr ocedure showed much lower tendenc y to form bromofor m during th e method d evelopme nt studies. This is thought to b e associ ated with lower le vels of pe roxides. This may be due to TAME being stored over molecular sieves (Sect. 7.1.3).

9. QUALITY CO NTROL
9.1 Each lab oratory using this me thod is re quired to operate a forma l Quality Co ntrol (QC) program. The requirements of this program consist of an Initial Demonstra tion of Capability (IDC) , and subsequent analysis in each analysis batch of a La boratory
552.3-17Reagent Blank (LRB), Continuing Calibration Check Standards (CCCs), a Laboratory Fortified Sample Ma trix (LFSM) , and eith er a Lab oratory Fortified Sample Ma trix Duplicat e (LFSMD) or a Field Duplicat e Sample. This sect ion detai ls the spe cific requirements for each QC paramete r. The QC criteria discussed in the following sections are summarized in Section 17, Tables 15 and 16. These cr iteria are considered the minimum acceptable QC criteria, and laboratories ar e encouraged to institute additional QC pract ices to me et their s pecific needs.
9.1.1 Process all quality control samples through all steps of Section 11, including methylation. Sample preservatives as described in Section 8.1 must be added prior to e xtractin g and ana lyzing the quality c ontrol sa mples.
9.2 INITIAL DEMONSTRATION OF CAPABILITY (IDC) – Requireme nts for the Initial Demonstr ation of Ca pability a re desc ribed in th e followi ng sectio ns and summ arized in Section 17, Table 15.
9.2.1 INITIAL DEMONSTRATION OF LOW SYSTEM BACKGROUND – Before any samples are analyzed, it must be demonstrated that a labor atory reagent blank (LRB) is reasonably free of contamination.
9.2.2 INITIAL DEMONSTRATION OF ACCURACY – Prior to the analysis of the IDC samples, verify calibration accurac y with the preparation and analysis of a mid-leve l QCS as def ined in Sec tion 9.10. I f the ana lyte rec overy is n ot + 30% of the expected value, the accura cy of the method is unacceptable. The source of the problem must be identified and corrected. After the a ccuracy of the calibration has been verifie d, prepa re and a nalyze 4 -7 replic ate LFBs ( or CCCs in thi s method) fortified at 10 μg/L, or near the mid-range of the initial calibra tion curve, according to the procedure describe d in Section 11. Sample preservatives as described in Section 8.1.2 must also be added to these samples. The avera ge recovery of the replicate value s must be within ± 20% of the expected value.
9.2.3 INITIA L DEMONST RATION O F PRECISION – Using the same set o f replic ate data generated for Section 9.2.2, calculate the standard deviation and relative standard deviation of the replicate recove ries. The relative standard deviation (RSD) of the results of the replicate analyses must be less than 20%.
9.2.4 DETECTION LIMIT (DL) DETERMINATION – Prepare, extract and analyze at least seven replicate LFBs at a concentration estimated to be ne ar the Detection
552.3-18Limit over a period of at least three days (both extrac tion and analysis should be conducted over at least three days) using the proc edure described in Section 11. The fortification level may be estimated by selecting a conc entration with a signal of 2 to 5 times the noise level. The appropriate concentration will be depe ndent upon the sensitivity of the GC/ECD system being used. Sample preservatives as described in Section 8.1.2 must be added to these samples. Calculate the Detection Limit using the equation
DL = St (n - 1, 1 - " = 0.99) where t (n - 1, 1 - " = 0.99) = Students t value for the 99% confidence level with n-1 degrees of freedom ( 3.143 for 7 re plicates) n = number of replicates, and S = standa rd devia tion of the replica te analy ses.
NOTE: Do not subtract blank values when performing DL calcula tions. The DL is a statistical determination of precision only. (1) If the DL replicates are fortified at a low enough concentration, it is likely that they will not meet precision and accuracy criteria, and may r esult in a calculated DL that is higher than the fortified concentration. Therefore no pre cision and accuracy criteria a re specified for the DL.
9.2.5 Minimum Reporting Level (MRL) – The MRL is the threshold concentration of an analyte that a laboratory can expe ct to accurately quantitate in an unknown sample. The MRL should be established at an analyte concentration that is at least 3 tim es the DL or at a c oncentr ation whic h would yie ld a signa l-to-nois e (S/N) ra tio of gre ater tha n or equa l to five. D epending upon the st udy’s dat a quality objectives it may be set at a higher concentration. The concentration of the lowest calibration standard must be at or below the MRL

. 9.2.6 METHOD MO DIFICATI ONS – The a nalyst is pe rmitted to modify GC c olumns, GC conditions (see Tables 1-4), and internal standards (see Sect. 7.2.2) or surrogate standards (see Sect. 7.2.3). Other de tectors (see Sect. 6.14) may be used if they have equivalent or better selectivity and have suf ficient sensitivity. Each time such method modifications are made, the analyst must repeat the proce dures of the IDC (Sect. 9.2).

552.3-199.3 LABORATORY REAGENT BLANK (LRB) – An LRB is required with each extrac tion batch (Sect. 3.1) of samples to determine the background system conta mination. If the LRB produces a peak within the retention time window of any analyte that would pre vent the determination of that analyte, determine the source of contamination and eliminate the interfe rence b efore p rocessi ng sample s. Backgr ound cont amination must be re duced to an acceptable level before proceeding. Background from method analytes or contamin ants that i nterfe re with the measur ement of method an alytes mus t be below 1/3 of the MRL. If the target analytes are detected in the LRB at concentrations equal to or greate r than this level, th en all da ta for the problem a nalyte( s) must be c onsidere d invalid for all samples in the extraction batch.
9.4 CONTINUING CALIBRATION CHECK (CCC) – CCC Standards are prepare d in the same extraction batch as the samples of interest. They must contain a ll compounds of interest, and they are extracted in the same ma nner as the Field Samples and calibration solutions u sed to pre pare the initial ca libration curve. C alibrati on chec ks, prepa red with the samples being analyzed, are require d at the beginning of each analysis batch, after every ten samples, and at the end of the analysis batch. See Section 10.3 for concentration requirements, frequenc y requirements, and acceptance c riteria.
9.5 LABORATORY FORTIFIED BLANK (LFB) – Since this method utilizes procedural calibration standards, which are fortified re agent waters, there is no difference between the LFB and the continuing calibration check standard. Consequently, the analysis of an LFB is not re quired; h owever , the acr onym LFB is us ed for c larity in t he IDC.
9.6 INTERNAL STANDARDS (IS) – The analyst must monitor the peak area of each internal standard in all injections during each analysis day. The IS response (as indicated by peak area) for any chr omatographic run must not deviate by more than ± 50% from the averag e area measure d during th e initial c alibrati on for tha t IS. A poor injection could cause th e IS are a to exce ed these criteri a. Injec t a secon d aliquot o f the susp ect extr act to determine whethe r the fa ilure is du e to poor i njection or instrum ent resp onse drif t.
9.6.1 If the reinjected aliquot produces an acc eptable internal standard response, report results f or that a liquot.
9.6.2 If the internal standard area for the reinjected extract deviates grea ter than 50% from the initial calibration average, the analyst should check the continuing calibration check standards that ran befor e and after the sample. If the continuing calibration check fails the criteria of Sec tion 10.3, recalibration is in order per
552.3-20Section 10

. If the c alibrati on standa rd is acc eptable , extrac tion of the sample should be repeated provided the sample is still within holding time. Otherwise, report r esults obta ined fro m the rein jected e xtract, but annota te as susp ect.
9.7 SURROGATE RECOVERY – The surrogate standard is fortified into the aqueous portion of all sample s, LRBs, CCCs, LFSMs, and L FSMDs prior to extra ction. It i s also added to the calibration standards. The surrogate is a mea ns of assessing method performance from extraction to final chr omatographic measurement. Calculate the recovery (R) for the surrogate using the e quation

where A = calculated surrogate concentr ation for the QC or Field Sample, and B = fortified concentration of the surrogate.
9.7.1 When surrogate recovery fr om a sample, blank, or CCC is less than 70% or greater than 130%, check (1) c alculations to locate possible errors, (2) standard solutions for degradation, (3) contamination, and (4) instrument performanc e. Correct the probl em and re analyze the extr act.
9.7.2 If the extract reanalysis meets the surroga te recovery criterion, report only data f or the rea nalyzed extrac t.
9.7.3 If the e xtract r eanalys is fails the 70-130 % recov ery cri terion, th e analys t should check the calibration by injecting the last calibration standard that passe d. If the calibration standard fails the criteria of Section 9.7.1, rec alibration is in order per Section 10 .2. If the calibra tion stand ard is ac ceptabl e, extra ction of th e sample should be repeated provided the sample is still within the holding time. If the reextracted sample also fails the recovery c riterion, report all data for that sample as suspect/surrogate recovery to inform the data use r that the results are suspect due to surrogate recovery.
9.8 LABORATO RY FORTIFI ED SAMPLE M ATRIX (L FSM) – Anal ysis of an LFSM (Sect. 3. 7) is req uired in e ach extr action ba tch and is used to de termine t hat the sa mple matrix doe s not adve rsely af fect met hod acc uracy. I f the occ urrenc e of tar get anal ytes in the samples is infrequent, or if historical trends are unavailable , a second LFSM or
552.3-21LFSMD must be prepar ed, extr acted, a nd analyz ed from a duplicat e field sa mple used to prepare the LFSM to assess method precision. Extraction batches that contain LFSMDs do not require the analysis of a Field Duplicate (Sect. 9.9). If a variety of different sample matrices are analyzed re gularly, for example, drinking water from groundwate r and surface water source s, method performance should be established for eac h. Over time, LFSM data should be documented for all routine sample sources for the labora tory.
9.8.1 Within each extraction batch, a minimum of one Field Sample is fortified as an LFSM for every 20 samples extracted. The LFSM is prepared by spiking a sample with an appr opriate amount of Analyte P DS (Sect. 7.2.4.2)

. Select a spiking concentration that is greater than or equal to the matrix backgr ound concentration, if known. Use historical data and rotate through the designated concentrations when selecting a fortifying conce ntration.
9.8.2 Calculate the recovery (R) for ea ch analyte using the equation

where A = measured concentration in the fortified sample, B = measured concentration in the unfortified sample, and C = fortification concentration.
9.8.3 Analyte recoveries may exhibit matrix bias. For samples fortified at or a bove their native concentration, recoveries should ra nge between 70 and 130%, except for low- level fo rtifica tion near or at the MRL (within a facto r of 2-tim es the MRL concentration) where 50 to 150% recove ries are acceptable. If the accuracy of any analyte falls outside the designated range, and the labora tory performance for that analyte is shown to b e in contr ol in the CCCs , the rec overy is j udged to b e matrix biased. The result for that analyte in the unfortified sample is labeled suspect/ matrix to i nform the data use r that the results a re suspe ct due to m atrix effec ts.
9.8.3.1 Because HAAs ar e disinfe ction by- products , many Fiel d Samples w ill contain a number of HAAs at varying concentra tions. Field Samples that have native HAA concentrations above the D L but below the MRL and are fortified at concentrations at or nea r the MRL should be corrected for

552.3-22the nativ e levels in order to obtain me aningful R values. This is the only permitted use of analyte results below the MRL.
9.9 FIELD DUPLICATE OR LABORATORY FORTIFIED SAMPLE MATRIX DUPLICAT E (FD or LF SMD) – With in each e xtractio n batch, a minimum of o ne Field Duplicate (FD) or Laboratory Fortified Sample Matrix Duplicate (L FSMD) must be analyzed. Duplicates check the pre cision associated with sample collection, preservation, storage , and labo ratory p rocedur es. HAAs are typi cally fo und in wat ers disinf ected w ith chlorine; however, if target analytes are not routinely observed in Field Samples, an LFSMD should be periodically analyzed rather than an FD.
9.9.1 Calculate the relative percent differ ence (RPD) for duplicate measurements (FD1 and FD2) using the equation

9.9.1.1 RPDs for Field Duplicates should fall in the range of ± 30%. Greater variabi lity may be observe d when Field Duplica tes have analyte
concen trations t hat are within a f actor of 2 of the MRL

. At these concentrations Field Duplicates should have RPDs that fall in the range of ± 50%. If the RPD of any analyte falls outside the designated range, a nd the laboratory performance for tha t analyte is shown to be in control in the CCC, the recovery is judged to be matrix biased. The result for that analyte in the unfortified sample is labeled suspect/matrix to inform the data use r that the results a re suspe ct due to m atrix ef fects.
9.9.2 If an LFSMD is analyzed instead of a Field Duplicate, calculate the relative percent difference (RPD) for duplicate LFSMs (LFSM and LFSMD) using the equation

9.9.2.1 RPDs for duplicate LFSMs should fall in the range of ± 30% for samples fortified at or above their native concentra tion. Greater variability may be observed when LFSMs are fortified at analyte conc entrations that are within a factor of 2 of the MRL. LFSMs fortified at these concentrations
552.3-23should have RPDs that fall in the range of ± 50% for samples fortified at or above their native concentration. If the RPD of any a nalyte falls outside the desig nated ra nge, and the labor atory pe rforman ce for t hat anal yte is shown to be in contro l in the CCC, t he reco very is ju dged to be matrix biased. The result for that analyte in the unfortified sample is labeled suspect/ matrix to i nform the data use r that the results a re suspe ct due to matrix ef fects.
9.10 QUALITY CONTROL SAMPLES (QCS) – As part of the IDC (Sect. 9.2), each time a new Ana lyte PDS (Se ct. 7.2.4 .2) is pre pared, a nd at lea st quarte rly, ana lyze a Q CS sample from a source different from the sour ce of the calibration standards. If a sec ond vendor is not avail able the n a diffe rent lot of the stand ard shoul d be used . The QCS should be p repare d and ana lyzed jus t like a CCC. Accept ance cr iteria f or the QCS i s identical to the CCCs; the calculated amount for each analyte must be + 30% of the expected value. If measured a nalyte concentrations are not of acce ptable accuracy, check the entir e analyt ical pro cedure to locate and corr ect the p roblem.

10. CALIBRATI ON AND STAN DARDIZAT ION
10.1 An acce ptable in itial calibration m ust be est ablished during the IDC and pr ior to analyzing Field or QC Samples. After initial calibration is successful, a Continuing Calibration Check (CCC) is required at the beginning and the end of each a nalysis batch, and after every tenth sample (Sect. 10.3). Bec ause this is a procedural standard method, the anal yst will ne ed to make a decisi on to inclu de eithe r an appr opriate number of CCCs or an entire initial calibration curve with each extra ction batch. Initial calibration must be repeated each time a major instrument modification is made or maintena nce is performed. Failure to meet CCC criteria may also require recalibration.
10.2 INITIA L CALIBRAT ION – This method use s the proc edural c alibrati on techni que to compensa te for inc omplete me thylation o f some of the targ et compou nds. This is most pronounced for the brominated trihaloacetic ac ids. Many of the QC criteria throughout this method are exp ressed i n terms of percen t recove ry. It sho uld be note d that the se recove ries are relative to the initi al proce dural cu rve rat her than absolute recove ries.
10.2.1 Establish GC opera ting para meters e quivalen t to the sug gested sp ecifica tions in Section 17, Table 1 (or Table 2). The GC system must be calibrated using the

552.3-24interna l standar d (IS) te chnique. Other co lumns or c onditions ma y be used if equivalent or better performance c an be demonstrated.
10.2.2 Prepare a set of at least 5 calibration standar ds as described in Section 7.2.5. The lowest concentration calibration standard must be at or below the MRL, which will depend on system sensitivity. It is recommended that at least four of the calibration standards be at concentrations grea ter than the MRL.
10.2.3 CALIBRATION – Use the GC data system software to genera te a linear regres sion or qua dratic c alibrati on curve using the i nternal standar d. The an alyst may choose whether or not to force zer o to obtain a curve that best fits the data. Examples of common GC system calibration curve options are: 1) A x /A is versus Q x /Q is ; and 2) RRF v ersus A x /A is . Establish a relative response factor by using the equation

where A x = integrated peak area of the a nalyte, A is = integrated peak area of the inter nal standard, Q x = quantity of analyte injected in ng or concentration units, Q is = quantity of internal standard injected in ng or concentra tion units, and RRF = relative response factor.
10.2.4 Acceptance criteria for the calibration of each analyte is determined by c alculating the conc entratio n of eac h analyte and surr ogate in e ach of th e analys es used to generate the calibration curve. Ea ch calibration point, except the lowest point, for each an alyte sho uld calc ulate to b e 70-130 % of its ex pected v alue. Th e lowest point should calculate to be 50-150% of its expected value. Labora tories that have dif ficulty a chieving these cr iteria w ill have tr ouble mee ting the QC requirements summarized in Section 10.3.2. These laboratories should rea nalyze the calib ration sta ndards, r estrict t he range of calibration, o r selec t an alter nate method of calibration.

552.3-2510.3 CONTINU ING CALI BRATION CH ECK (CCC) – An appro priate n umber of CCCs must be prepared with each extraction batc h. The CCC verifies the initial calibration at the beginning and the end of each analysis batch, and a fter every 10 th sample during analyse s. In this c ontext, a “sample ” is consi dered to be a Field Sample. LF SMs, LFSMDs, FSDs, and CCCs are not counted as samples. The beginning CCC for each analysis batch must be at or below the MRL in order to verify instrument sensitivity prior to any ana lyses. If standar ds have b een pre pared su ch that a ll analyte s are not in the same Calibration Standard, it may be necessary to analyze two Calibration Standard solutions to meet this requirement. Subsequent CCCs should alternate between a medium and a high concentration standard.
10.3.1 Inject an aliquot of the appropriate concentra tion calibration check standard solution prepared with the extraction batch and analyze using the same conditions used during the initial calibration.
10.3.2 Calculate the concentration of each ana lyte and surrogate in the check standard. The calculated amount for each ana lyte for medium and high level CCCs must be ± 30% of the expected value. The calc ulated amount for the lowest calibration level fo r each a nalyte mu st be withi n ± 50% of t he expe cted val ue. If these conditions do not exist, then all data for the problem analyte must be considered invalid, and remedial action should be taken which may require r ecalibration. Any Field Sa mple extr acts tha t have be en analy zed sinc e the las t accep table calibration verification should be reanalyzed a fter adequate calibration has been restore d. For Extr action Ba tches wit h more tha n 10 Field Sa mples the a nalyst may either extract and analyze athird CCC or reanalyze the mid-level or highlevel CCC a s the fina l CCC.

11. PROCEDURE

11.1 SAMPLE EXTRACTION
11.1.1 Remove the samples f rom stora ge (Sect . 8.3) an d allow the m to equilib rate to room temperature.
11.1.2 Place 40 mL of the water sample into a precleane d 60-mL glass vial with a PTFElined screw cap using a clean, gradua ted cylinder for each sample.

552.3-2611.1.3 Add 20 μL of surroga te standa rd (20 μg/m L of 2-br omobutano ic acid in MTBE per Section 7.2.3.2) to the aqueous sample.
NOTE: When fortif ying an aq ueous sam ple with c omponents that are containe d in MTBE solution, be sure that the needle of the syringe is well below the surface of the water. After injection, cap the sample and inve rt once. This will insure that the stand ard solut ion is mixed well.
11.1.4 Adjust the pH to less than or equal to 0.5 by adding up to 2 mL of concentrated sulfuric acid. Ca p, mix and t hen che ck the pH with narr ow range pH paper (Sect. 6.11). Substitution of other acids is not allowed.
11.1.5 Add appr oximately 18 g of muf fled sodi um sulfate (Sect. 7. 1.4) and immediate ly shake until almost all is dissolved. Substitutio n of other salts for sodium sulfate is not allowed

. Sodium sulfate is added to increase the ionic strength of the aque ous phase and thus f urther d rive the haloace tic acids into the or ganic phase. T he additi on of salt also dec reases the solubi lity of MTBE or TAME in the aqueous phase and allows greater volumetric r ecovery of the extraction solvent. The addition of this salt should be done immediately after the addition of the sulfu ric acid so that the heat gen erated from the a ddition of the acid (Sect. 11.1.4) will help dissolve the salt.
11.1.6 Add exactly 4.0 mL MTBE with IS or TAME with IS (Sect. 7.2.2.3) and shake vigorously for three minutes by hand. This may be accomplished for a entire Extraction Batch using a test tube rack.
11.1.7 Allow the phases to separa te for a pproxima tely 5 minut es.
11.2 SAMPLE METHYLATION WITH ACIDIC METHANOL
11.2.1 Using a pasteur pipet, transfer 3 mL of the upper MTBE or TAME la yer to a 15-mL graduated conical centrifuge tube.
11.2.2 Add 3 mL of 10% sulfuric acid in methanol (Sect. 7.1.12) to each centrifuge tube. Cap the tube.
11.2.3 Methylation of the method analytes is accomplished during this step. Careful control of both reaction time and reaction temperature are critical to method
552.3-27precision and accuracy. (9) Place the tubes in a heating b lock (or sand bath ) at 50 ± 2 °C (for MTBE) or 60 ± 2 °C (for TAME) and heat for 2 hours (± 10 min). The tubes should fit snugly into the heating block to ensure proper heat transfer. Verify the reaction temperature by plac ing a thermometer into a tube containing water rather than inserting it into the block to ensure an acc urate reading. Placing the thermometer directly in the heating block well or sand bath will give a higher temperature reading than the actual sample te mperature. The MTBE reaction temperature is set at its highest practical limit (50 °C), since MTBE boils at 55 °C. Similarly, the TAME reaction temperature has been set at 60 °C, since me thanol boils at 65 °C. This he lps preve nt solvent loss from t he reac tion tubes

. 11.2.3.1 Even at 2 hours, methylation for some of the more sterically hindered compounds like TBAA, CDBAA and BDCAA is not complete. Shortening reaction time will decrease methylation efficienc ies for compounds and result in lower precision.
11.2.3.2 Methylation efficiencies are increa sed with increasing temperature (and time). The TAME procedure has higher methylation eff iciencies than MTBE procedure for the sterically hindered HA As like the brominated trihaloacetic acids (Sect. 11.2.3.1) and is more prec ise for these targets. Methylation temperature, however, should not be increased above the recommended reaction temperat ures (Sect. 11.2.3).
11.2.3.3 Lower re action te mperatur es or tim es are no t allowed. Care sho uld be taken to ensure that the c alibrati on standa rds are heated i dentica lly to Field Samples in the extraction batch.
11.2.3.4 Methylation may be accomplished by heating the reaction tubes with a water ba th, provid ed the wa ter bath is not cove red in a w ay as to c ause the entir e tube to b e heate d. If tube walls ar e heate d, the tube s can lose some of their contents leading to higher variability in analytical results. A water bath that is cover ed with a l ayer of small, flo ating pla stic spheres may be used (Sect. 6.10).
11.2.4 Remove the centrifuge tubes from the heating source a nd allow them to cool before removing their ca ps.

552.3-2811.2.5 Add 7 mL of a 150 g/L sodium sulfate solution (Sect. 7.1.10) to each centrifuge tube. Vortex each tube to ensure full equilibration betwee n the phases. Allow the two phases to settle fully, but do not allow the tubes to sit more than a few minutes. Adding the sodium sulfate solution may cause some loss of the formed HAA-esters through acid-catalyze d hydrolysis over prolonged periods.
11.2.6 Remove and discard the lower (acidic aque ous methanol) phase from each tube with a long pasteur pipet. Leave no more than 0.3 mL of aqueous phase to ensure complete neutralization in the following step.
11.2.7 Add 1 mL of saturated sodium bicarbonate solution (Sect. 7.1.11). Vortex eac h centrifuge tube for several seconds a t least four times to complete the neutralization reaction. Loosen the tube caps af ter the first agitation to release the evolved C O 2 . 11.2.8 Transfer 1 mL of the upper ether laye r to an auto-sampler vial. A duplicate vial should be f illed using the exce ss extra ct.
11.2.9 An alyze the sample s as soon a s possible

. Store the extrac ts at # -10 °C (Sect. 8.4).
11.3 GAS CHROMATOGRAPHY
11.3.1 The instrument used in the development of this method was equipped with a low volume (150 μ L) micro electron capture detector (ECD). Other configurations are allowed as described in Section 6.14.
11.3.2 COLUMN SEL ECTION A ND INSTA LLATION – Strict at tention sh ould be pa id to established column installation guidelines with regard to the proper cutting and placement of the capillary columns within the instrument. The brominated trihaloacetic acids are particularly se nsitive to the condition of the injection port and GC column. If the response for these or other method a nalytes diminish, trimming approximately 0.5 m from the head of the column and replacing the GC inlet liner often restores the response for these a nalytes. Quartz inlet liners and inlet liners with standard deactivation were found to require le ss frequent maintenance than those with Siltek TM deactivation for this method. If conditions in the lab oratory necessitate fre quent col umn trimming , a guard column is recommended.

552.3-2911.3.3 Method development was conducted with the GC set in constant pressure mode. If constant velocity mode is used by the analyst, linear velocities should be reduced from those listed in Tables 1-4 to obtain similar resolution.
11.4 ANALYSIS OF EXTRACTS
11.4.1 Establish operating conditions as described in Section 17, Table 1 or Table 2 (Table 3 or 4 if pe rforming confirma tion). Conf irm that r etention times, compound separation, and resolution are similar to those summarized in Tables 1- 4 and Figures 1- 4.
11.4.2 Establish an appropriate relative retention time window for ea ch target and surrogate to identify them in the QC and Field Samples. This should be based on
measure ments of a ctual re lative re tention tim e varia tion for e ach comp ound in standard solutions analyzed on the GC over the course of time. Plus or minus three times the standard deviation of the relative retention time observe d for each compound while establishing the initial calibration can be used to calculate a suggested window size; however, the experience of the analyst should weigh heavily on the determination of the appropriate retention window.
11.4.3 Calibrat e the instr ument as d escribe d in Sectio n 10.2 or c onfirm the calibra tion is still valid b y analyz ing CCCs as de scribed in Section 10.3. Begi n analyz ing Field and QC Samples at their appropriate frequency by injec ting aliquots under the same conditions used to establish the initial calibration.
11.4.4 The analyst must not extrapolate beyond the established calibration range

. If an analyte result exceeds the range of the initial calibration curve, the extract may be diluted with MTBE or TAME containing the internal standard (Sect. 7.2.1.3), and the dilute d extrac t injecte d. Acce ptable su rrogate perfor mance ( Sect. 9.7 ) should be determined from the undiluted sample extract. Incorpor ate the dilution factor into final concentration calculations. The dilution will also affect analyte MRLs.

12. DATA ANA LYSIS AND C ALCULATION

12.1 Identify the method analytes in the sample chromatogram by comparing the r etention time of the suspect peak to retention time of an analyte peak in a c alibration standard.

552.3-30Surrogat e reten tion times s hould be c onfirmed to be withi n accep tance lim its (Sect. 11.4.2) even if no target compounds are detecte d.
12.2 Calculate the analyte concentrations using the initial calibration curve ge nerated as described in Section 10.2. Quantitate only those values that fall between the MRL and the highest calibration standard. Samples with target analyte responses that exc eed the highest standard require dilution and reanalysis (Sect. 11.4.4).
12.3 Analyte i dentific ations sho uld be con firmed us ing the co nfirmati on column s pecifie d in Table 3 ( or Table 4) or ano ther col umn that is d issimilar t o the prima ry column

. GC/MS confirma tion is acc eptable if the an alyte co ncentra tions are sufficie nt.
12.4 Adjust the calcula ted conc entratio ns of the d etecte d analyte s to refle ct the init ial sample volume and any dilutions performed.
12.5 Analyte concentrations are reported in μg/L as the total fr ee acid (usually to 2 significant figures); however, calculations should use all available digits of prec ision.

13. METHOD PERFORMANCE
13.1 PRECISION, ACCURACY, AND DETECTION LIMITS – Tables for these data ar e presented in Section 17. Detection Limits are presented in Table 5 a nd were calculated using the formula presented in Section 9.2.4. Single laboratory precision and acc uracy data are presented in Tables 6-11.
13.2 SAMPLE STORAGE STABILITY STUDIES – An analyte storage stability study was conducted by fortifying the analytes (10 μg/L of each ana lyte) into a chlorinated surface water that was collected, preserve d, and stored as described in Section 8. The average of triplicate analyses, conducted on days 0, 3, 7, and 14 are pr esented in Table 12.
13.3 EXTRACT STORAGE STABILITY STUDIES – Extract storage stability studies were conducted on TAME and MTBE extracts obtained from a chlor inated surface water fortified at 10 μg/L. The average of triplicate injections ar e reported in Tables 13 and 14. Extract storage stability c an decli ne in the p resenc e of per oxides. T his is discu ssed in Section 8.4.

552.3-3114. POLLUTION P REVENTION
14.1 This method utilizes liquid-liquid microextraction to extract analytes from water. It requires the use of very small volumes of organic solvent and ver y small quantities of pure analytes, thereby minimizing the potential hazards to both the analyst and the environment as compared to the use of large volumes of orga nic solvents in conventional liquid-liquid extractions.
14.2 For information about pollution prevention that may be applicable to laboratory operati ons, cons ult “Less is Better: Labora tory Chemi cal Mana gement f or Waste Reduction” available from the American Chemical Society’s De partment of Government Relations and Science Policy, 1155 16th Street N.W., Washington, D.C., 20036.

15. WASTE MANAGEMENT
15.1 The analytical procedures describe d in this method generate relatively small amounts of waste since only small amounts of reagents and solvents are used. The matrices of concern are finished drinking water or sour ce water. However, the Age ncy requires that laboratory waste management practice s be conducted consistent with all applicable rules and regulations, and that laboratories protect the air, wa ter, and land by minimizing and controlli ng all re leases f rom fume h oods and b ench ope rations. Also, comp liance is required with any sewage discharge pe rmits and regulations, particularly the hazardous waste ide ntificat ion rules and land d isposal re striction s. For fur ther info rmation on waste managem ent, cons ult “The W aste Man agement Manual f or Labor atory Per sonnel” a lso available from the American Chemical Society at the addr ess in Section 14.2.

16. REFERENCE S
1. Glaser, J.A., Foerst, D.L., McKee, G.D., Quave, S.A., a nd Budde, W.L., “Trace Analyses for Wastewaters,” Environ. Sci. Tec hnol. , 15 (1981) 1426-1435.
2. Giam, C.S., Chan, H.S. , and Nef , G.S., "Sen sitive Met hod for D etermina tion of Phth alate Ester Pla sticizer s in Open- Ocean Bi ota Sample s," Analytical Chemistry , 47, 2225 (1975).

552.3-323. Giam, C.S., and Chan, H.S., "Control of Blanks in the Analysis of Phthalates in Air and Ocean Biota Samples," U.S. National Bureau of Standards, Special Publication 442, 701-708, (1976).
4. "OSHA Safety and Health Standards, General Industry," (29CRF1910). Occupa tional Safety and Health Administration, OSHA 2206, (Revised, Jan. 1976).
5. “Carcinogens-Working with Carcinogens,” Publication No. 77-206, Depa rtment of Health, E ducation , and We lfare, Public He alth Service, Cen ter for D isease Co ntrol, National Institute of Occupational Safety and Health, Atlanta, Ge orgia, August 1977.

6. “Safety In Acad emic Chem istry Lab oratorie s,” 3rd E dition, Ame rican Che mical Soc iety Publication, Committee on Chemical Safety, Washington, D.C., (1979).

7. ASTM Annual Book of Standards, Part II, Volume 11.01, D3370-82, "Standard Practice for Sampling Water," American Society for Testing and Mater ials, Philadelphia, PA, 1986.
8. Pepich, B. V., Domino , M.M., Mun ch, D.J. a nd Fair, P. S. “Valid ating Samp le Preservation Techniques and Holding Times for the Approved Compliance Monitoring Methods f or Haloa cetic Ac ids Under the U.S. EP A’s Stage 1 D/DBP Rule ,” Submitte d to Wat. Res., Sept. 2002.
9. Xie, Y., Rashid, I., Zhou, H., and Gammie, L. “Acidic Methanol Methylation for HAA Analysis: Limitations and Possible Solutions” JAWWA, 94:11, 115-122 (Nov. 2002).

552.3-3317. TABLES, DIAG RAMS, FLOW CHARTS, AN D VALIDAT ION DATA
TABLE 1: CHROMATOGRAPHIC CONDITIONS AND AVERAGE RETENTION TIME DATA FOR TH E PRIMAR Y COLUMN (DB-1701 ) USING MTB E

Compound Average T r (min)* RSD (% ) Monochloroacetic acid (MCAA) 9.29 0.03 Monobromoacetic acid (MBAA) 14.19 0.02 Dalapon 14.69 0.02 Dichloroacetic acid (DCAA) 15.07 0.02 Bromoform** 17.12 0.01 Trichloroacetic acid (TCAA) 18.89 0.01 1,2,3 Tri chloropr opane (I S) 20.69 0.01 Bromochloroacetic acid (BCAA) 21.22 0.01 2-bromob utanoic a cid (SUR) 21.63 0.01 Bromodichloroacetic acid (BDCAA) 23.60 0.01 Dibromoacetic acid (DBAA) 24.01 0.005 Chlorodibromoacetic acid (CDBAA) 25.55 0.004 Tribromoacetic acid (TBAA) 26.88 0.003
*The average retent ion ti me represents the average of 8 i njecti ons of fort ifi ed reagent water extract s that had been forti fied at 10 μ g/L of ea ch an alyte. **B rom ofo rm is not a ta rget a naly te. RT valu e is pro vide d fo r info rm ation only

. Prima ry Co lum n: DB -170 1, 30 m x 0.25 mm i.d., 0.25 μm film thickn ess. Injector: Inje ctor tempera ture , 210 o C; 2-mm str aight quart z li ner; inj ecti on volume 1 μL; s pli tl ess inj ecti on hold f or 45 sec t hen purge @ 30 mL/min.
GC Prog ram : (for MTBE ) 40 o C ini ti al he ld for 10 minutes , progr am at 2. 5 o C/min t o 65 o C, t hen 10 o C/min t o 85 o C, then 20 o C/min t o 205 o C, hol d for 7 min.
Detector: Agilent Micro ECD (150 μL volume); dete ctor tempera ture , 290 o C; de tec tor make up ga s 95% Ar/ 5% CH 4 at 20 mL/min.
Carrier G as: Helium (UHP), set at c onsta nt pre ssur e. I nit ial carr ier gas vel ocit y (at 40 o C) 33 cm/sec.
Data Col lect ion: Agilent GC Chemstation wit h a digit izat ion rat e of 20 Hz.

552.3-34TABLE 2: CHROMATOGRAPHIC CONDITIONS AND AVERAGE RETENTION TIME DATA FOR THE PRIMARY COLUMN (DB-1701) USING TAME

Compound Average T r (min)* RSD (%) Monochloroacetic acid (MCAA) 5.94 0.08 Monobromoacetic acid (MBAA) 8.76 0.04 Dalapon 9.17 0.04 Dichloroacetic acid (DCAA) 9.34 0.04 Bromoform** 11.06 0.02 Trichloroacetic acid (TCAA) 12.28 0.02 1,2,3 Tri chloropr opane (I S) 13.56 0.01 Bromochloroacetic acid (BCAA) 13.87 0.01 2-bromob utanoic a cid (SUR) 14.20 0.01 Bromodichloroacetic acid (BDCAA) 15.78 0.004 Dibromoacetic acid (DBAA) 16.14 0.003 Chlorodibromoacetic acid (CDBAA) 17.58 0.002 Tribromoacetic acid (TBAA) 18.89 0.02
*The average retent ion ti me represents the average of 8 i njecti ons of fort ifi ed reagent water extract s that had been forti fied at 10 μ g/L of ea ch an alyte. **Bromoform is not a t arget anal yte. RT value i s provi ded for infor mation onl y.
Prima ry Co lum n: DB -170 1, 30 m x 0.25 mm i.d., 0.25 μm film thickn ess. Injector: Inje ctor tempera ture , 210 o C; 2-mm str aight quart z li ner; inj ecti on volume 1 μL; s pli tl ess inj ecti on hold f or 45 sec t hen purge @ 30 mL/min.
GC Prog ram : (for TAM E) 55 o C ini ti al hol d 8 minutes , progr am at 2. 5 o C/min t o 65 o C, t hen 10 o C/min t o 85 o C, t hen 20

o C/min t o 205 o C, hold f or 7 min.
Detector: Agilent Micro ECD (150 μL volume); dete ctor tempera ture , 290 o C; de tec tor make up ga s 95% Ar/ 5% CH 4 at 20 mL/min.
Carrier G as: Helium (UHP), set at c onsta nt pre ssur e. I nit ial carr ier gas vel ocit y (at 55 o C) 32 cm/sec.
Data Col lect ion: Agilent GC Chemstation wit h a digit izat ion rat e of 20 Hz.

552.3-35TABLE 3: CHROMATOGRAPHIC CONDITIONS AND AVERAGE RETENTION TIME DATA FOR TH E CONFIRM ATION COLU MN (DB-5 .625) USIN G MTBE

Compound Average T r (min)* RSD (%) Monochloroacetic acid (MCAA) 5.28 0.04 Monobromoacetic acid (MBAA) 8.31 0.01 Dichloroacetic acid (DCAA) 9.05 0.01 Dalapon 10.63 0.02 Bromoform** 12.74 0.02 Trichloroacetic acid (TCAA) 14.73 0.02 Bromochloroacetic acid (BCAA) 15.25 0.02 1,2,3 Tri chloropr opane (I S) 15.65 0.01 2-bromob utanoic a cid (SUR) 17.41 0.02 Dibromoacetic acid (DBAA) 21.08 0.01 Bromodichloroacetic acid (BDCAA) 21.39 0.01 Chlorodibromoacetic acid (CDBAA) 24.35 0.002 Tribromoacetic acid (TBAA) 25.94 0.000
*The average retent ion ti me represents the average of 8 i njecti ons of fort ifi ed reagent water extract s that had been forti fied at 10 μ g/L of ea ch an alyte. **B rom ofo rm is not a ta rget a naly te. RT valu e is pro vide d fo r info rm ation only

. Confir mation Co lum n: DB -5.625 , 30 m x 0.25 mm i.d., 0.25 μm film thickn ess. Injector: Inje ctor tempera ture , 210 o C; 2-mm str aight quart z li ner; inj ecti on volume 1 μL ; s pli tl ess inj ecti on hold f or 45 sec t hen purge @ 30 mL/min.
GC Prog ram : (for MTBE ) 40 o C ini ti al he ld for 10 minutes , progr am at 2. 5 o C/min t o 65 o C, t hen 10 o C/min t o 85 o C, then 20 o C/min t o 205 o C,. Po st run 210 oC h old fo r 7 m in.
Detector: Agilent Micro ECD (150 μL volume); dete ctor tempera ture , 290 o C; de tec tor make up ga s 95% Ar/ 5% CH 4 at 20 mL/min.
Carrier G as: Helium (UHP), set at c onsta nt pre ssur e. I nit ial carr ier gas vel ocit y (at 40 o C) 32 cm/sec.
Data Col lect ion: Agilent GC Chemstation wit h a digit izat ion rat e of 20 Hz.

552.3-36TABLE 4: CHROMATOGRAPHIC CONDITIONS AND AVERAGE RETENTION TIME DATA FOR THE CONFIRMATION COLUMN (DB-5.625) USING TAME

Compound Average T r (min)* RSD (%) Monochloroacetic acid (MCAA) 4.07 0.26 Monobromoacetic acid (MBAA) 5.47 0.14 Dichloroacetic acid (DCAA) 5.81 0.12 Dalapon 6.61 0.10 Bromoform** 7.97 0.07 Trichloroacetic acid (TCAA) 9.11 0.06 Bromochloroacetic acid (BCAA) 9.44 0.05 1,2,3 Tri chloropr opane (I S) 9.79 0.05 2-bromob utanoic a cid (SUR) 11.05 0.03 Dibromoacetic acid (DBAA) 13.77 0.01 Bromodichloroacetic acid (BDCAA) 14.01 0.01 Chlorodibromoacetic acid (CDBAA) 16.45 0.008 Tribromoacetic acid (TBAA) 17.96 0.004
*The average retent ion ti me represents the average of 8 i njecti ons of fort ifi ed reagent water extract s that had been forti fied at 10 μ g/L of ea ch an alyte. **Bromoform is not a t arget anal yte. RT value i s provi ded for infor mation onl y.
Confir mation Co lum n: DB -5.625 , 30 m x 0.25 mm i.d., 0.25 μm film thickn ess. Injector: Inje ctor tempera ture , 210 o C; 2-mm str aight quart z li ner; inj ecti on volume 1 μL; s pli tl ess inj ecti on hold f or 45 sec t hen purge @ 30 mL/min.
GC Prog ram : (for TAM E) 55 o C ini ti al he ld for 8 minutes , progr am at 2. 5 o C/min t o 65 o C, t hen 10 o C/min t o 85 o C, then 20 o C/min t o 205 o C,. Post run 210 oC hol d for 7 min.
Detector: Agilent Micro ECD (150 μL volume); dete ctor tempera ture , 290 o C; de tec tor make up ga s 95% Ar/ 5% CH 4 at 20 mL/min.
Carrier G as: Helium (UHP), set at c onsta nt pre ssur e. I nit ial carr ier gas vel ocit y (at 55 o C) 32 cm/sec.
Data Col lect ion: Agilent GC Chemstation wit h a digit izat ion rat e of 20 Hz.

552.3-37TABLE 5: DETECTION LIMITS IN REAGENT WATER USING THE MTBE AND TAME PROCEDUR ES

Compound MTBE TAME Fortification Level (μg/L) Detection Limit a (μg/L) Fortification Level (μg/L) Detection Limit a (μg/L) Monochloroacetic acid (MCAA) 1.00 0.17 1.00 0.20 Monobromoacetic acid (MBAA) 0.50 0.027 0.50 0.13 Dalapon 0.50 0.024 0.50 0.14 Dichloroacetic acid (DCAA) 0.50 0.020 0.50 0.084 Trichloroacetic acid (TCAA) 0.50 0.019 0.50 0.024 Bromochloroacetic acid (BCAA) 0.50 0.016 0.50 0.029 Bromodichloroacetic acid (BDCAA) 0.50 0.034 0.50 0.031 Dibromoacetic acid (DBAA) 0.50 0.012 0.50 0.021 Chlorodibromoacetic acid (CDBAA) 0.50 0.054 0.50 0.035 Tribromoacetic acid (TBAA) 0.50 0.11 0.50 0.097

a Fortified reagent waters were extra cted and analyzed over 3 days for 7- 9 replicates following the procedu re outline d in Sectio n 9. MTBE de tection li mits were determin ed with 9 r eplicate s. TAME detectio n limits wer e deter mined with 7 replic ates.

552.3-38TABLE 6: PRECISION A ND ACCU RACY IN R EAGENT WATER FORTIFIED A T 1.0 μg/L

Compound MTBE TAME Mean Recovery (%) RSD (%) (n=8) S/N Ratio a Mean Recovery (%) RSD (%) (n=8) S/N Ratio a
Monochloroacetic acid (MCAA) 95.8 4.0 12 81.4 5.1 17 Monobromoacetic acid (MBAA) 92.2 1.8 81 90.7 3.7 92 Dalapon 97.5 1.6 110 92.8 2.1 150 Dichloroacetic acid (DCAA) 93.8 1.6 190 97.8 2.2 190 Trichloroacetic acid (TCAA) 105 0.52 580 107 0.90 520 Bromochloroacetic acid (BCAA) 102 0.36 580 103 0.94 740 Bromodichloroacetic acid (BDCAA) 117 1.2 1400 113 1.1 1800 Dibromoacetic acid (DBAA) 105 0.63 1300 105 0.86 1800 Chlorodibromoacetic Acid (CDBAA) 125 2.3 650 112 1.5 1600 Tribromoacetic acid (TBAA) 128 4.1 970 109 1.8 1100

a Signal-to-noise ratios were calculated for ea ch target compound peak by dividing the peak height for each compound by the peak-to-peak noise, which w as determined for each component from the me thod blank over a period of time equal to the full peak width in the target ana lyte’s retention time window.

552.3-39TABLE 7: PRECISION A ND ACCU RACY IN R EAGENT WATER FORTIFIED A T 10 μg/L

Compound MTBE TAME Mean Recovery a (%) RSD (%) (n=8) Mean Recovery a (%) RSD (%) (n=8) Monochloroacetic acid (MCAA) 101 3.5 102 2.5 Monobromoacetic acid (MBAA) 101 2.2 101 1.6 Dalapon 99.8 0.88 99.9 0.50 Dichloroacetic acid (DCAA) 98.2 0.73 100 0.33 Trichloroacetic acid (TCAA) 102 1.2 101 1.1 Bromochloroacetic acid (BCAA) 101 0.72 101 0.65 Bromodichloroacetic acid (BDCAA) 107 2.4 103 1.2 Dibromoacetic acid (DBAA) 102 0.52 101 0.59 Chlorodibromoacetic acid (CDBAA) 111 3.8 104 1.6 Tribromoacetic acid (TBAA) 113 4.7 104 2.0

552.3-40TABLE 8: PRECISION AND ACCURACY IN CHLORINATED SURFACE WATER FORTIFIED A T 1.0 μg/L

Compound MTBE TAME Mean Recovery a (%) RSD (%) (n=8) Mean Recovery b (%) RSD (%) (n=8) Monochloroacetic acid (MCAA) 112 6.2 131 6.2 Monobromoacetic acid (MBAA) 99.5 2.3 98.6 4.2 Dalapon 107 2.2 103 3.5 Dichloroacetic acid (DCAA) 103 1.5 106 3.8 Trichloroacetic acid (TCAA) 89.2 1.4 89.0 1.1 Bromochloroacetic acid (BCAA) 99.5 1.6 102 2.2 Bromodichloroacetic acid (BDCAA) 91.7 4.0 87.5 1.8 Dibromoacetic acid (DBAA) 103 2.8 103 4.5 Chlorodibromoacetic acid (CDBAA) 95.5 7.1 94.4 3.3 Tribromoacetic acid (TBAA) 110 8.1 111 4.3

a Recoveries were correc ted for haloacetic acid (HAA) c oncentrations in the unfortified matrix, based on an average value of three me asurements. HAAs detected in the unfortified matrix included MBAA (0.14 μg/L), DCAA (0.56 μg/L), TCAA (0.32 μg/L), BCAA (1.1 μg/L), BDCAA (0.68 μg/L), DBAA (2.2 μg/L), CDBAA (0.91 μg/L), and TBAA (1.0 μg/L).

b Recoveries were correc ted for haloacetic acid (HAA) c oncentrations in the unfortified matrix, based on an average value of three me asurements. HAAs detected in the unfortified matrix included MBAA (0.22 μg/L), DCAA (0.78 μg/L), TCAA (0.36 μg/L), BCAA (2.0 μg/L), BDCAA (0.62 μg/L), DBAA (4.0 μg/L), CDBAA (0.82 μg/L), and TBAA (0.79 μg/L).

552.3-41TABLE 9: PRECISION AND ACCURACY IN CHLORINATED SURFACE WATER FORTIFIED A T 10 μg/L

Compound MTBE TAME Mean Recovery a (%) RSD (%) (n=8) Mean Recovery b (%) RSD (%) (n=8) Monochloroacetic acid (MCAA) 97.8 3.1 97.1 3.8 Monobromoacetic acid (MBAA) 98.8 2.0 98.8 2.0 Dalapon 99.6 0.90 97.7 0.42 Dichloroacetic acid (DCAA) 98.0 1.1 97.6 0.42 Trichloroacetic acid (TCAA) 99.8 0.80 100 1.4 Bromochloroacetic acid (BCAA) 101 1.4 101 0.93 Bromodichloroacetic acid (BDCAA) 103 4.3 104 2.3 Dibromoacetic acid (DBAA) 102 1.4 101 0.93 Chlorodibromoacetic acid (CDBAA) 105 5.5 105 3.2 Tribromoacetic acid (TBAA) 108 6.3 106 3.4

a Recoveries were correc ted for haloacetic acid (HAA) c oncentrations in the unfortified matrix, based on an average value of three me asurements. HAAs detected in the unfortified matrix included MBAA (0.14 μg/L), DCAA (0.56 μg/L), TCAA (0.32 μg/L), BCAA (1.1 μg/L), BDCAA (0.68 μg/L), DBAA (2.2 μg/L), CDBAA (0.91 μg/L), and TBAA (1.0 μg/L).

b Recoveries were correc ted for haloacetic acid (HAA) c oncentrations in the unfortified matrix, based on an average value of three me asurements. HAAs detected in the unfortified matrix included MBAA (0.22 μg/L), DCAA (0.78 μg/L), TCAA (0.36 μg/L), BCAA (2.0 μg/L), BDCAA (0.62 μg/L), DBAA (4.0 μg/L), CDBAA (0.82 μg/L), and TBAA (0.79 μg/L).

552.3-42TABLE 10: PRECISION AND ACCURACY IN CHLORINATED GROUND WATER FORTIFIED A T 1.0 μg/L

Compound MTBE TAME Mean Recovery a (%) RSD (%) (n=8) Mean Recovery b (%) RSD (%) (n=8) Monochloroacetic acid (MCAA) 126 4.5 124 9.5 Monobromoacetic acid (MBAA) 113 3.8 98.9 2.6 Dalapon 112 1.1 87.3 2.7 Dichloroacetic acid (DCAA) 102 3.7 107 3.2 Trichloroacetic acid (TCAA) 92.2 1.2 103 2.1 Bromochloroacetic acid (BCAA) 106 3.8 104 2.4 Bromodichloroacetic acid (BDCAA) 105 6.1 106 4.0 Dibromoacetic acid (DBAA) 111 5.3 105 1.7 Chlorodibromoacetic acid (CDBAA) 103 8.8 103 4.5 Tribromoacetic acid (TBAA) 99.2 7.3 103 3.2

a Recoveries were correc ted for haloacetic acid (HAA) c oncentrations in the unfortified matrix, based on an average value of three me asurements. HAAs detected in the unfortified matrix included MBAA (0.07 μg/L), Dalapon (0.19 μg/L), DCAA (2.6 μg/L), TCAA (1.1 μg/L), BCAA (3.0 μg/L), BDCAA (1.8 μg/L), DBAA (3.3 μg/L), CDBAA (1.8 μg/L), and TBAA (1.1 μg/L).

b Recoveries were correc ted for haloacetic acid (HAA) c oncentrations in the unfortified matrix, based on an average value of three me asurements. HAAs detected in the unfortified matrix included MBAA (0.28 μg/L), Dalapon (0.35 μg/L) DCAA (2.7 μg/L), TCAA (1.6 μg/L), BCAA (3.2 μg/L), BDCAA (2.4 μg/L), DBAA (2.5 μg/L), CDBAA (1.7 μg/L), and TBAA (0.54 μg/L).

552.3-43TABLE 11: PRECISION AND ACCURACY IN CHLORINATED GROUND WATER FORTIFIED A T 10 μg/L

Compound MTBE TAME Mean Recovery a (%) RSD (%) (n=8) Mean Recovery b (%) RSD (%) (n=8) Monochloroacetic acid (MCAA) 104 1.8 99.7 1.7 Monobromoacetic acid (MBAA) 100 1.4 98.7 1.1 Dalapon 97.8 1.1 97.9 0.63 Dichloroacetic acid (DCAA) 95.9 1.0 97.1 0.83 Trichloroacetic acid (TCAA) 98.2 0.81 101 1.4 Bromochloroacetic acid (BCAA) 100 0.53 99.8 1.4 Bromodichloroacetic acid (BDCAA) 106 1.8 106 2.3 Dibromoacetic acid (DBAA) 101 0.89 101 1.6 Chlorodibromoacetic acid (CDBAA) 110 2.8 106 2.8 Tribromoacetic acid (TBAA) 116 3.4 105 2.6

a Recoveries were correc ted for haloacetic acid (HAA) c oncentrations in the unfortified matrix, based on an average value of three me asurements. HAAs detected in the unfortified matrix included MBAA (0.07 μg/L), Dalapon (0.19 μg/L), DCAA (2.6 μg/L), TCAA (1.1 μg/L), BCAA (3.0 μg/L), BDCAA (1.8 μg/L), DBAA (3.3 μg/L), CDBAA (1.8 μg/L), and TBAA (1.1 μg/L).

b Recoveries were correc ted for haloacetic acid (HAA) c oncentrations in the unfortified matrix, based on an average value of three me asurements. HAAs detected in the unfortified matrix included MBAA (0.28 μg/L), Dalapon (0.35 μg/L) DCAA (2.7 μg/L), TCAA (1.6 μg/L), BCAA (3.2 μg/L), BDCAA (2.4 μg/L), DBAA (2.5 μg/L), CDBAA (1.7 μg/L), and TBAA (0.54 μg/L).

552.3-44TABLE 12: SAMPLE HOLD ING TIME DA TA FOR SAM PLES FROM A CHLORINAT ED SURFACE W ATER FORTIF IED WITH METH OD ANALYT ES a

Compound Day 0 R b (%) Day 3 R b (%) Day 7 R b (%) Day 14 R b (%) Monochloroacetic Acid (MCAA) 97.9 96.8 98.5 104 Monobromoacetic Acid (MBAA) 107 99.6 105 109 Dalapon 104 104 103 99.7 Dichloroacetic Acid (DCAA) 101 99.0 102 98.8 Trichloroacetic Acid (TCAA) 101 102 98.8 96.2 Bromochloroacetic Acid (BCAA) 101 99.3 100 97.8 Bromodichloroacetic Acid (BDCAA) 112 111 113 110 Dibromoacetic Acid (DBAA) 102 99.1 100 96.9 Chlorodibromoacetic Acid (CDBAA) 117 115 119 116 Tribromoacetic Acid (TBAA) 123 118 124 121

a All samples were fortified at 10 μg/L. All samples were stored at 10 o C for 48 hours, and at 6 o C thereafter.

b Recoveries were correc ted for haloacetic acid (HAA) c oncentrations in the unfortified matrix, based on an average value of three me asurements. HAAs detected in the unfortified matrix included MBAA (0.30 μg/L), DCAA (0.73 μg/L), TCAA (0.33 μg/L), BCAA (2.0 μg/L), BDCAA (0.67 μg/L), DBAA (4.3 μg/L), CDBAA (0.91 μg/L), and TBAA (1.1 μg/L).

552.3-45TABLE 13: MTBE EXTRACT HOLDING TIME DATA FOR SAMPLES FROM A CHLORINAT ED SURFAC E WATER FORT IFIED WITH M ETHOD ANALYTES a

Compound Initial R (%) Day 7 R (%) Day 14 R (%) Day 21 R (%) Monochloroacetic Acid (MCAA) 99.0 98.6 100 99.3 Monobromoacetic Acid (MBAA) 99.7 98.2 98.1 99.0 Dalapon 99.0 96.7 98.1 97.8 Dichloroacetic Acid (DCAA) 97.9 96.3 97.5 97.3 Trichloroacetic Acid (TCAA) 99.3 99.6 98.5 99.1 Bromochloroacetic Acid (BCAA) 100 101 100 101 Bromodichloroacetic Acid (BDCAA) 99.3 106 102 103 Dibromoacetic Acid (DBAA) 101 102 101 102 Chlorodibromoacetic Acid (CDBAA) 99.7 107 102 103 Tribromoacetic Acid (TBAA) 102 110 102 106

a Extract storage stability was conducted on three of the e ight extracts from the precision and accurac y study conducted in chlorinated surface water (fortified at 10 μg/L) reported in Table 9. Sample storage stability is expressed as a recovery value (%) calculated as described in Section 9.8.2. All values have been corrected for bac kground levels in the unfortified sample based on triplicate measureme nts as described in Table 9. Extracts were stored a t < -10 °C.

552.3-46TABLE 14: TAME EXTRACT HOLDING TIME DATA FOR SAMPLES FROM A CHLORINAT ED SURFAC E WATER FORT IFIED WITH M ETHOD ANALYTES a

Compound Initial R (%) Day 7 R (%) Day 14 R (%) Day 21 R (%) Day 28 R (%) Monochloroacetic Acid (MCAA) 98.2 95.8 99.2 98.3 98.3 Monobromoacetic Acid (MBAA) 98.9 98.7 99.3 98.8 98.8 Dalapon 100 101 101 100 101 Dichloroacetic Acid (DCAA) 97.5 96.4 97.3 97.4 97.0 Trichloroacetic Acid (TCAA) 99.6 101 100 102 102 Bromochloroacetic Acid (BCAA) 101 102 101 102 102 Bromodichloroacetic Acid (BDCAA) 103 104 102 108 108 Dibromoacetic Acid (DBAA) 100 101 100 102 102 Chlorodibromoacetic Acid (CDBAA) 103 106 102 110 110 Tribromoacetic Acid (TBAA) 104 108 103 110 111

a Extract storage stability was conducted on three of the e ight extracts from the precision and accurac y study conducted in chlorinated surface water (fortified at 10 μg/L) reported in Table 9. Sample storage stability is expressed as a recovery value (%) calculated as described in Section 9.8.2. All values have been corrected for bac kground levels in the unfortified sample based on triplicate measureme nts as describ ed in Tab le 9. Extr acts wer e stored at < -10 ° C.

552.3-47TABLE 15: INITIAL DEM ONSTRATION OF CAPABI LITY (IDC) REQUIREME NTS
Method Reference Requirem ent Specification and Frequency Accept ance Cri teria

Section 9.2.1

Section 9.2.2

Section 9.2.3 Initial Demonstration of Low Method Background Initial Demonstration of Accuracy

Initial Demonstration of Precision Analyze LRB prior to any other IDC steps

Analyze QCS Analyze 4-7 repl icate LFB s fortified at midrange concentration.

Calculate standard deviation and RSD for replicates used in the Initial Demonstration of Accuracy (Sect. 9.2.2) Over a p eriod of three da ys, prepare a minimum of 7 replica te LFBs for tified at a concentration estimated to be near the Detection Limit. Analyze the replicates through all steps of the analysis. Calculate the Detection Limit using the equation in Section 9.2.4. Demonstr ate that L RB is reasonably free of contamination.
Recovery for analytes must be ± 30% of expected value. Mean recovery must be within ± 20% of expected value.

RSD must be # 20%.

Note: Data from DL replicates are not required to meet method precision and accuracy criteria. If the DL replicates are fortified at a low enough concentration, it is likely that they will not meet precision and accuracy criteria. Section 9.2.4 Detecti on Limit Determination

Section 9.2.5 Minimum Reporting Limit Estimate after determining DL and prior to analysis of Field Samples At least 3 times the D L or at a concen tration w hich yiel ds a signal-to -noise r atio of a t least 5.

552.3-48TABLE 16: QUALITY CONTROL REQUIREMENTS (SUMMARY)

Method Reference Requirem ent Specification and Frequency Accept ance Cri teria

Section 8.3 Sample Shipment and Storage

Section 8.4 Sample Holding Time

Section 8.4 Extract Holding Time Sample re sults are valid only if extracts are properly stored and analyze d within ex tract ho ld time.

Section 9.3 Laboratory Reagent Blank (LRB) With each extraction batch of up to 20 samples Demonstrate that all target analytes in LRB are below 1 / 3 the MRL and that interferences do not prevent the identification and quantification of method analytes. 1 / 3 the MRL, r esults for all problem analytes in extraction batch are invalid. If targets exceed Samples must not exceed 10 °C within 48 hours after collection. in laboratory must not exceed 6 °C. 14 days with approp riate preservation and storage
21 days a t # -10 °C protected from light (MTBE) 28 days a t # -10 °C protected from light (TAME) Samples stored Sample re sults are valid only if samples are properly collected, preserved, and stored.

Sample re sults are valid only if samples a re extr acted w ithin sample hold time.

552.3-49TABLE 16: QUALITY CONTROL REQUIREMENTS (SUMMARY)
Method Reference Requirem ent Specific ation and Frequency Accept ance Cri teria

Sections 9.4 and 10.3 Continuing Calibration Check (CC C) Verify initial calibration by analyzing a calibration standard at the beginning of each analysis batch, after e very 10 sa mples, and after the last sample.
Low CCC - # MRL Mid CCC - near midpoint in initial calibration curve High CCC - ne ar highe st calibration standard 1) The result for each analyte must be 70-130% o f the exp ected va lue for a ll but the low est stand ard. lowest standard must be 50-150% of the expected value. 2) The peak area of internal standa rds must be 50-150% of the average peak area calculated during the initial calibration. Results for analytes that do not meet IS criteria or are not bracketed by acceptable CCCs are invalid. The

Section 9.6 Internal Standard (IS)

Section 9.7 Surrogat e Standard (SUR)

Section 9.8 Laboratory Fortified Sample Matrix (LFSM) and Laboratory Fortified Matrix Duplicat e (LFSMD) 1,2,3 Tri chloropr opane is added to the extraction solvent.

2-bromob utanoic a cid [80-58- 0] is adde d to all calibration standards and samples, including QC samples. Analyze one LFSM per analysis batch (20 samples or less) fortified with metho d analyte s at a concentration greater than the native concentration. LFSMD should be used in place of Field Dupli cate if frequency of detects for target analytes is low. Peak are a counts f or the IS i n all injections must be within 50-150% of the average peak area calculated during the initial calibration. does not meet criteria, corresponding target results are invalid. Surrogate recovery must be 70-130% of the ex pected v alue. If surroga te fails this criterion, report all results for sample as suspect/surrogate recovery.
Recoveries at mid and high levels not within 70-130% or low-level recoveries not within 50-150% of the fortifie d amount ma y indicat e a matri x effec t. Target analyte RPDs for LFSMD not within ± 30% at mid and high levels of fortification and within ± 50% near MRL may indicate a matrix effect. If the IS

552.3-50Method Reference Requirem ent Specific ation and Frequency Accept ance Cri teria

Section 9.9 Field Duplicates (FD) Extract and analyze at least one FD with each extraction batch (20 samples or less). A LFSMD may be substitute d periodi cally for a FD when the frequency of detects for target analytes is low. Target analyte RPDs for FD should be within ± 30% at mid and high level concentrations and within ± 50% near MRL.

Section 9.10 Quality Control Sample (QCS) Analyzed when new Primary Dilution Standards (PDS) are prepar ed, durin g the IDC, or quarterly. Results must be 70-130% of the expecte d values.

Section 10.2 Initial Calibration Use internal standard calibra tion tech nique to generate a calibration curve. se at lea st 5 standar d conce ntrations

. When ea ch calib ration sta ndard is calculated as an unknown using the calibration curve, the result must be 70-130% o f the exp ected va lue for a ll except the lowest standard, which must be 50-150% of the expected value. U

552.3-51FIGURE 1: CHROMATOG RAM OF THE H ALOACETIC A CIDS ON A D B-1701 COL UMN USIN G THE CHROMATOGRAPHIC CONDITIONS GIVEN IN TABLE 1 USING THE MTBE PROCEDURE

552.3-52FIGURE 2: CHROMATOG RAM OF THE H ALOACETIC A CIDS ON A D B-1701 COL UMN USIN G THE CHROMATOGRAPHIC CONDITIONS GIVEN IN TABLE 2 USING THE TAME PROCEDURE

552.3-53FIGURE 3: CHROMATOG RAM OF THE H ALOACETIC A CIDS ON A D B-5.625 C OLUMN USIN G THE CHROMATOGRAPHIC CONDITIONS GIVEN IN TABLE 3 USING THE MTBE PROCEDURE

552.3-54FIGURE 4: CHROMATOG RAM OF THE H ALOACETIC A CIDS ON A D B-5.625 C OLUMN USIN G THE CHROMATOGRAPHIC CONDITIONS GIVEN IN TABLE 4 USING THE TAME PROCEDURE

552.3-55