552.2-1

METHOD 552.2 DETERMINATION OF HALOACETIC ACIDS AND DALAPON IN DRINKING

WATER BY LIQUID-LIQUID EXTRACTION, DERIVATIZATION AND GAS

CHROMATOGRAPHY WITH ELECTRON CAPTURE DETECTION.

Revision 1.0

J.W. Hodgeson (USEPA), J. Collins and R.E. Barth (Technology Applications Inc.) - Method

552.0, (1990)

J.W. Hodgeson (USEPA), D. Becker (Technology Applications Inc.) - Method 552.1, (1992)

D.J. Munch, J.W. Munch (USEPA) and A.M. Pawlecki (International Consultants, Inc.), Method

552.2, Rev. 1.0, (1995)

NATIONAL EXPOSURE RESEARCH LABORATORY

OFFICE OF RESEARCH AND DEVELOPMENT

U.S. ENVIRONMENTAL PROTECTION AGENCY

CINCINNATI, OHIO 45268
552.2-2

METHOD 552.2 DETERMINATION OF HALOACETIC ACIDS AND DALAPON

IN DRINKING WATER BY LIQUID-LIQUID EXTRACTION, DERIVATIZATION

AND GAS CHROMATOGRAPHY WITH ELECTRON CAPTURE DETECTION

1. SCOPE AND APPLICATION

1.1 This is a gas chromatographic (GC) method (1-8) applicable to the determination of the

listed halogenated acetic acids in drinking water, ground water, raw source water and

water at any intermediate treatment stage. In addition, the chlorinated herbicide,

Dalapon, may be determined using this method.

 Chemical Abstract Services

 Analyte Registry Number 

Bromochloroacetic Acid (BCAA) 5589-96-3

Bromodichloroacetic Acid (BDCAA) 7113-314-7

Chlorodibromoacetic Acid (CDBAA) 5278-95-5

Dalapon 75-99-0

Dibromoacetic Acid (DBAA) 631-64-1

Dichloroacetic Acid (DCAA) 79-43-6

Monobromoacetic Acid (MBAA) 79-08-3

Monochloroacetic Acid (MCAA) 79-11-8

Tribromoacetic Acid (TBAA) 75-96-7

Trichloroacetic Acid (TCAA) 76-03-9

1.2 This method is applicable to the determination of the target analytes over the

concentration ranges typically found in drinking water (1,2,4). Experimentally

determined method detection limits (MDLs) for the above listed analytes are provided

in Table 2. Actual MDLs may vary according to the particular matrix analyzed and the

specific instrumentation employed. The haloacetic acids are observed ubiquitously in

chlorinated drinking water supplies at concentrations ranging from <1 to >50 :g/L.

1.3 This method is designed for analysts skilled in liquid-liquid extractions, derivatization

procedures and the use of GC and interpretation of gas chromatograms. Each analyst

must demonstrate the ability to generate acceptable results with this method using the

procedure described in Section 9.3.

1.4 When this method is used for the analyses of waters from unfamiliar sources, it is

strongly recommended that analyte identifications be confirmed by GC using a dissimilar column or by GC/MS if concentrations are sufficient.

2. SUMMARY OF METHOD

2.1 A 40-mL volume of sample is adjusted to pH <0.5 and extracted with 4-mL of methyltert-butyl-ether (MTBE). The haloacetic acids that have been partitioned into the

organic phase are then converted to their methyl esters by the addition of acidic
552.2-3

methanol followed by slight heating. The acidic extract is neutralized by a backextraction with a saturated solution of sodium bicarbonate and the target analytes are

identified and measured by capillary column gas chromatography using an electron

capture detector (GC/ECD). Analytes are quantitated using procedural standard

calibration. 

3. DEFINITIONS

3.1 INTERNAL STANDARD (IS) -- A pure analyte(s) added to a sample, extract, or standard solution in known amount(s) and used to measure the relative responses of other

method analytes and surrogates thatare components of the same sample or solution. 

The internal standard must be an analyte that is not a sample component.

3.2 SURROGATE ANALYTE (SA) -- A pure analyte(s), which is extremely unlikely to be

found in any sample, and which is added to a sample aliquot in known amount(s)

before extraction or other processing and is measured with the same procedures used

to measure other sample components. The purpose of the SA is to monitor method

performance with each sample.

3.3 LABORATORY DUPLICATES (LD1 AND LD2) -- Two aliquots of the same sample

designated as such in the laboratory. Each aliquot is extracted, derivatized and

analyzed separately with identical procedures. Analyses of LD1 and LD2 indicate the

precision associated with laboratory procedures, but not with sample collection,

preservation, or storage procedures.

3.4 FIELD DUPLICATES (FD1 AND FD2) -- Two separate samples collected at the same

time and place under identical circumstances and treated exactly the same throughout

field and laboratory procedures. Analyses of FD1 and FD2 give a measure of the

precision associated with sample collection, preservation and storage, as well as with

laboratory procedures.

3.5 LABORATORY REAGENT BLANK (LRB) -- An aliquot of reagent water or other blank

matrix that are treated exactly as a sample including exposure to all glassware,

equipment, solvents, reagents, internal standards, and surrogates that are used with

other samples. The LRB is used to determine if method analytes or other interferences

are present in the laboratory environment, the reagents, or the 

apparatus.

3.6 FIELD REAGENT BLANK (FRB) -- An aliquot of reagent water or other blank matrix

that is placed in a sample container in the laboratory and treated as a sample in all

respects, including shipment to the sampling site, exposure to sampling site conditions,

storage, preservation and all analytical procedures. The purpose of the FRB is to

determine if method analytes or other interferences are present in the field environment.

3.7 LABORATORY FORTIFIED BLANK (LFB) -- An aliquot of reagent water or other blank

matrix to which known quantities of the method analytes are added in the laboratory. 
552.2-4

The LFB is analyzed exactly like a sample, and its purpose is to determine whether the

methodology is in control, and whether the laboratory is capable of making accurate

and precise measurements.

3.8 LABORATORY FORTIFIED SAMPLE MATRIX (LFM) -- An aliquot of an environmental

sample to which known quantities of the method analytes are added in the laboratory. 

The LFM is analyzed exactly like a sample, and its purpose is to determine whether the

sample matrix contributes bias to the analytical results. The background 

concentrations of the analytes in the sample matrix must be determined in a separate

aliquot and the measured values in the LFM corrected for background concentrations.

3.9 STOCK STANDARD SOLUTION (SSS) -- A concentrated solution containing one or

more method analytes prepared in the laboratory using assayed reference materials or

purchased from a reputable commercial source.

3.10 PRIMARY DILUTION STANDARD SOLUTION (PDS) -- A solution of several analytes

prepared in the laboratory from stock standard solutions and diluted as needed to prepare calibration solutions and other needed analyte solutions.

3.11 CALIBRATION STANDARD (CAL) -- A solution prepared from the primary dilution

standard solution and stock standard solutions of the internal standards and surrogate

analytes. The CAL solutions are used to calibrate the instrument response with respect

to analyte concentration.

3.12 QUALITY CONTROL SAMPLE (QCS) -- A solution of method analytes of known

concentration which is used to fortify an aliquot of reagent water or sample matrix. 

The QCS is obtained from a source external to the laboratory and different from the

source of calibration standards. It is used to check laboratory performance with 

externally prepared test materials.

3.13 LABORATORY PERFORMANCE CHECK SOLUTION (LPC) -- A solution of selected method analytes used to evaluate the performance of the instrumental system with

respect to a defined set of method criteria. 

3.14 METHOD DETECTION LIMIT (MDL) -- The minimum concentration of an analyte that

can be identified, measured and reported with 99% confidence that the analyte

concentration is greater than zero.

3.15 MATERIAL SAFETY DATA SHEET (MSDS) -- Written information provided by vendors

concerning a chemical's toxicity, health hazards, physical properties, fire and reactivity

data including storage, spill, and handling precautions.

3.16 ESTIMATED DETECTION LIMIT (EDL) -- Defined as either the MDL or a level of a

compound in a sample yielding a peak in the final extract with a signal to noise (S/N)

ratio of approximately 5, whichever is greater.
552.2-5

3.17 PROCEDURAL STANDARD CALIBRATION -- A calibration method where aqueous

calibration standards are prepared and processed (e.g. purged, extracted and/or

derivatized) in exactly the same manner as a sample. All steps in the process from

addition of sampling preservatives through instrumental analyses are included in the

calibration. Using procedural standard calibration compensates for any inefficiencies in

the processing procedure.

3.18 CONTINUING CALIBRATION CHECK (CCC) -- A calibration standard containing one or

more method analytes, which is analyzed periodically to verify the accuracy of the

existing calibration curves or response factors for those analytes.

4. INTERFERENCES

4.1 Method interferences may be caused by contaminants in solvents, reagents, glassware

and other sample processing apparatus that lead to discrete artifacts or elevated

baselines in chromatograms. All reagents and apparatus must be routinely demonstrated to be free from interferences under the conditions of the analysis by analyzing

laboratory reagent blanks as described in Section 9.5. Subtracting blank values from

sample results is not permitted.

4.1.1 Glassware must be scrupulously cleaned. Clean all glassware as soon as

possible after use by thoroughly rinsing with the last solvent used in it. Follow

by washing with hot water and detergent and thorough rinsing with tap water

and reagent water. Drain and heat in an oven or muffle furnace at 400°

C for

1 hr. Do not heat volumetric ware but instead rinse three times with HPLC

grade or better acetone. Thorough rinsing with reagent grade acetone may be

substituted for the heating provided method blank analysis confirms no

background interferant contamination is present. Thermally stable materials

such as PCBs may not be eliminated by these treatments. After drying and

cooling, store glassware in a clean environment free of all potential contamination. To prevent any accumulation of dust or other contaminants, store glassware inverted or capped with aluminum foil.

4.1.2 The use of high purity reagents and solvents helps to minimize interference

problems. Each new bottle of solvent should be analyzed before use. An

interference free solvent is a solvent containing no peaks yielding data at $

MDL (Table 2) and at the retention times of the analytes of interest. Purification of solvents by distillation in all-glass systems may be required. 

4.2 Interfering contamination may occur when a sample containing low concentrations of

analytes is analyzed immediately following a sample containing relatively high concentrations of analytes. Routine between-sample rinsing of the sample syringe and

associated equipment with MTBE can minimize sample cross-contamination. After 

analysis of a sample containing high concentrations of analytes, one or more injections

of MTBE should be made to ensure that accurate values are obtained for the next

sample.
552.2-6

4.3 Matrix interferences may be caused by contaminants that are coextracted from the

sample. The extent of matrix interferences will vary considerably from source to

source, depending upon the water sampled. Analyte identifications should be confirmed using the confirmation column specified in Table 1 or by GC/MS if the concentrations are sufficient.

4.4 Bromochloroacetic acid coelutes with an interferant on the DB-1701 confirmation

column. The interferant has been tentatively identi-fied as dimethyl sulfide. However,

because of the difference in peak shapes, the peak for the ester of BCAA tends to "ride

on" the interferant peak and quantitative confirmation can be performed by manual

integration that includes only the peak area of the target ester.

4.5 Methylation using acidic methanol results in a partial decarboxylation of tribromoacetic

acid (8). Therefore a substantial peak for bromoform will be observed in the

chromatograms. Its elution does not, however, interfere with any other analytes. 

Furthermore, this demonstrates the need for procedural standards to establish the calibration curve by which unknown samples are quantitated.

5. SAFETY

5.1 The toxicity or carcinogenicity of each reagent used in this method has not been

precisely defined; however, each chemical compound must be treated as a potential

health hazard. From this viewpoint, exposure to these chemicals must be minimized. 

The laboratory is responsible for maintaining a current awareness file of OSHA regulations regarding the safe handling of the chemicals specified in this method. A reference file of material safety data sheets should also be made available to all personnel

involved in the chemical analysis. Additional references to laboratory safety are

available and have been identified (9-11) for the information of the analyst.

5.2 The toxicity of the extraction solvent, MTBE, has not been well defined. Susceptible

individuals may experience adverse affects upon skin contact or inhalation of vapors. 

Therefore protective clothing and gloves should be used and MTBE should be used only

in a chemical fume hood or glove box. The same precaution applies to pure standard

materials.
552.2-7

6. APPARATUS AND EQUIPMENT 

6.1 SAMPLE CONTAINERS -- Amber glass bottles, approximately 50 mL, fitted with

Teflon-lined screw caps. 

6.2 EXTRACTION VIALS -- 60 mL clear glass vials with teflon-lined screw caps.

6.3 VIALS -- Autosampler, 2.0 mL vials with screw or crimp cap and a teflon-faced seal.

6.4 STANDARD SOLUTION STORAGE CONTAINERS -- 10-20 ml amber glass vials 

with teflon lined-screw caps.

6.5 GRADUATED CONICAL CENTRIFUGE TUBES WITH TEFLON-LINED SCREW CAPS --

15-mL with graduated 1 mL markings.

6.6 BLOCK HEATER (or SAND BATH) -- Capable of holding screw cap conical centrifuge

tubes in Section 6.4.

6.7 PASTEUR PIPETS -- Glass, disposable.

6.8 PIPETS -- 2.0 mL and 4.0 mL, type A, TD, glass. 

6.9 VOLUMETRIC FLASKS -- 5 ml, 10 mL.

6.10 MICRO SYRINGES -- 10 :L, 25 :L, 50 :L, 100 :L, 250 :L, 500 :L and 1000 :L.

6.11 BALANCE -- analytical, capable of weighing to 0.0001 g.

6.12 GAS CHROMATOGRAPH -- Analytical system complete with gas chromatograph

equipped for electron capture detection, split/splitless capillary or direct injection,

temperature programming, differential flow control, and with all required accessories

including syringes, analytical columns, gases and strip-chart recorder. A data system is

recommended for measuring peak areas. An autoinjector is recommended for improved precision of analyses. The gases flowing through the electron capture detector

should be vented through the laboratory fume hood system. 

6.13 PRIMARY GC COLUMN -- DB-5.625 [fused silica capillary with chemically bonded

(5% phenyl)-methylpolysiloxane)] or equivalent bonded, fused silica column, 30m x

0.25mm ID, 0.25 :m film thickness.

6.14 CONFIRMATION GC COLUMN -- DB-1701 [fused silica capillary with chemically

bonded (14% cyanopropylphenyl)-methylpolysiloxane)] or equivalent bonded, fused

silica column, 30 m x 0.25 mm ID, 0.25 :m film thickness.
552.2-8

7. REAGENTS AND STANDARDS

7.1 REAGENT WATER -- Reagent water is defined as a water in which an interference is

not observed $ to the MDL of each analyte of interest.

7.1.1 A Millipore Super-Q water system or its equivalent may be used to generate

deionized reagent water. Distilled water that has been passed through

granular charcoal may also be suitable.

7.1.2 Reagent water is monitored through analysis of the laboratory reagent blank (Section 9.5).

7.2 SOLVENTS

7.2.1 METHYL-TERT-BUTYL ETHER -- High purity, demonstrated to be 

free of analytes and interferences, redistilled in glass if 

necessary.

7.2.2 METHANOL -- High purity, demonstrated to be free of 

analytes and interferences.

7.2.3 ACETONE -- High purity, demonstrated to be free of analytes 

and interferences.

7.3 REAGENTS

7.3.1 SODIUM SULFATE, Na2SO4 -- (ACS) granular, anhydrous. If interferences are

observed, it may be necessary to heat the sodium sulfate in a shallow tray at

400o

C for up to 4 hr. to remove phthalates and other interfering organic substances. Alternatively, it can be extracted with methylene chloride in a

Soxhlet apparatus for 48 hr. Store in a capped glass bottle rather than a

plastic container.

7.3.2 COPPER II SULFATE PENTAHYDRATE, CuSO4

.

5H2O -- ACS reagent

grade.

7.3.3 SODIUM BICARBONATE, NaHCO3 -- ACS reagent grade.

7.3.4 AMMONIUM CHLORIDE, NH4Cl -- ACS reagent grade, used to convert

free chlorine to monochloramine. Although this is not the traditional

dechlorination mechanism, ammonium chloride is categorized as a

dechlorinating agent in this method.

7.4 SOLUTIONS

7.4.1 10% H2SO4/METHANOL SOLUTION -- Use caution when preparing

sulfuric acid solutions. To prepare a 10% solution, add 5 mL sulfuric
552.2-9

acid dropwise (due to heat evolution) to 20-30 mL methanol contained

in a 50.0 mL volumetric flask that has been placed in a cooling bath. 

Then dilute to the 50.0 mL mark with methanol.

7.4.2 SATURATED SODIUM BICARBONATE SOLUTION -- Add sodium

bicarbonate to a volume of water, mixing periodically until the solution

has reached saturation.

7.5 STANDARDS

7.5.1 1,2,3-TRICHLOROPROPANE, 99+% -- For use as the internal standard. 

Prepare an internal standard stock standard solution of 1,2,3-trichloropropane

in MTBE at a concentration of approximately 1 mg/mL. From this stock

standard solution, prepare a primary dilution standard in MTBE at a

concentration of 25 :g/mL.

7.5.2 2,3-DIBROMOPROPIONIC ACID, 99+% -- For use as a surrogate compound. 

Prepare a surrogate stock standard solution of 2,3-dibromopropionic acid in

MTBE at a concentration of approximately 1 mg/mL. From this stock

standard solution, prepare a primary dilution standard in MTBE at a

concentration of 10 :g/mL.

7.5.3 STOCK STANDARD SOLUTION (SSS)

Prepare separate stock standard solutions for each analyte of interest at a

concentration of 1-5 mg/mL in MTBE. Method analytes may be obtained as

neat materials or ampulized solutions (> 99% purity) from a number of

commercial suppliers. These stock standard solutions should be stored at -

10o

C and protected from light. They are stable for at least one month but

should be checked frequently for signs of evaporation.

 

7.5.3.1. For analytes which are solids in their pure form, prepare stock

standard solutions by accurately weighing approximately 0.01

to 0.05 grams of pure material in a 10.0 mL volumetric flask. 

Dilute to volume with MTBE. When a compound purity is assayed

to be 96% or greater, the weight can be used without correction to

calculate the concentration of the stock standard. 

7.5.3.2. Stock standard solutions for analytes which are liquid in their

pure form at room temperature can be accurately prepared in the

following manner.

7.5.3.3. Place about 9.8 mL of MTBE into a 10.0 mL volumetric flask. 

Allow the flask to stand, unstoppered, for about 10 minutes to

allow solvent film to evaporate from the inner walls of the

volumetric, and weigh to the nearest 0.1 mg.
552.2-10

7.5.3.4. Use a 10 :L syringe and immediately add 10.0 :L of standard

material to the flask by keeping the syringe needle just above the

surface of the MTBE. Be sure that the standard material falls

dropwise directly into the MTBE without contacting the inner wall

of the volumetric.

7.5.3.5. Reweigh, dilute to volume, stopper, then mix by inverting the flask

several times. Calculate the concentration in milligrams per

milliliter from the net gain in weight. 

7.5.4 PRIMARY DILUTION STANDARD (PDS) -- Prepare the primary dilution

standard solution by combining and diluting stock standard solutions with

MTBE (the surrogate stock standard solution was prepared in Section 7.5.2). 

This primary dilution standard solution should be stored at -10°C and

protected from light. It is stable for at least one month but should be checked

before use for signs of evaporation. As a guideline to the analyst, the primary

dilution standard solution used in the validation of this method is described

below. 

Concentration, :g/mL

Monochloroacetic Acid

Monobromoacetic Acid

Dalapon

Dichloroacetic Acid

Trichloroacetic Acid

Bromochloroacetic Acid

Dibromoacetic Acid

Bromodichloroacetic Acid

Chlorodibromoacetic Acid

Tribromoacetic Acid

2,3-Dibromopropionic Acid (surr.)

60

40

40

60

20

40

20

40

100

200

100

This primary dilution standard is used to prepare calibration standards, which

comprise five concentration levels of each analyte with the lowest standard

being at or near the MDL of each analyte. The concentrations of the other

standards should define a range containing the expected sample

concentrations or the working range of the detector.

 

NOTE: When purchasing commercially prepared standards, solutions

prepared in methanol must not be used because it has been found that the

haloacetic acids are subject to spontaneous methylation when stored in this

solvent (12). Furthermore, tribromoacetic acid has been found to be unstable

in methanol because it undergoes decarboxylation when stored in this solvent.
552.2-11

7.5.4.1. Include the surrogate analyte, 2,3-dibromopropionic acid, within

the primary dilution standard prepared in Section 7.5.4. By

incorporating the surrogate into the primary dilution standard, it is

diluted alongside the target analytes in the standard calibration

curve. This is done so that the peaks for the surrogate and the

ester of chlorodibromo-acetic acid, which elute fairly closely, are

relatively close in size and adequate resolution is therefore insured. 

Furthermore, if a sample should have a very large concentration of

chlorodibromo-acetic acid, it may be impossible to obtain an

accurate measurement of surrogate recovery. If this happens,

reextraction with a higher surrogate concentration would be an

option. 

7.5.6 LABORATORY PERFORMANCE CHECK STANDARD (LPC) -- A low level

calibration standard can serve as the LPC standard. 

8. SAMPLE COLLECTION, PRESERVATION AND STORAGE

8.1 SAMPLE VIAL PREPARATION 

8.1.1 Grab samples must be collected in accordance with conventional sampling

practices (13) using amber glass containers with TFE-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

(NH4Cl) to the sample container in an amount to produce a concentration of

100 mg/L in the sample. For a typical 50 mL sample, 5 mg of ammonium

chloride is added. 

NOTE: Enough ammonium chloride must be added to the sample to convert

the free chlorine residual in the sample matrix to combined chlorine. Typically,

the ammonium chloride concentration here will accomplish that. If high

doses of chlorine are used, additional ammonium chloride may be required.

8.2 SAMPLE COLLECTION

8.2.1 Fill sample bottles to just overflowing but take care not to flush out the

ammonium chloride.

8.2.2 When sampling from a water tap, open the tap and allow the system to flush

until the water temperature has stabilized (usually about 3-5 minutes). 

Remove the aerator so that no air bubbles can be visibly detected and collect

samples from the flowing system.

8.2.3 When sampling from an open body of water, fill a 1-quart wide-mouth bottle

or 1-liter beaker with sample from a representative area, and carefully fill

sample vials from the container.
552.2-12

8.2.4 After collecting the sample in the bottle containing the ammonium

chloride, seal the bottle and agitate by hand for 1 min.

8.3 SAMPLE STORAGE/HOLDING TIMES

8.3.1 Samples must be iced or refrigerated at 4o

C and maintained at these

conditions away from light until extraction. Synthetic ice (i.e., blue ice) is not

recommended. Holding studies performed to date have suggested that, in

samples preserved with NH4Cl, the analytes are stable for up to 14 days. 

Since stability may be matrix dependent, the analyst should verify that the

prescribed preservation technique is suitable for the samples under study.

8.3.2 Extracts (Section 11.2.7) must be stored at 4o

C or less away from light in

glass vials with Teflon-lined caps. Extracts must be analyzed within 7 days

from extraction if stored at 4°C or within 14 days if stored at -10°C or less.

9. QUALITY CONTROL

9.1 Each laboratory that uses this method is required to operate a formal quality control

(QC) program. Minimum quality control requirements are monitoring the laboratory

performance check standard, initial demonstration of laboratory capability, performance

of the method detection limit study, analysis of laboratory reagent blanks and

laboratory fortified sample matrices, determination of surrogate compound recoveries

in each sample and blank, monitoring internal standard peak area or height in each

sample, blank and CCC, and analysis of QC samples. Additional QC practices may be

added.

9.2 LABORATORY PERFORMANCE CHECK STANDARD (LPC)

At the beginning of an analysis set, prior to any calibration standard or sample analysis

and after an initial solvent analysis, a laboratory performance check standard must be

analyzed. This check standard insures proper performance of the GC by evaluation of

the instrument parameters of detector sensitivity, peak symmetry, and peak resolution. 

It furthermore serves as a check on the continuity of the instrument's performance. In

regards to sensitivity, it allows the analyst to ascertain that this parameter has not

changed drastically since the analysis of the MDL study. Inability to demonstrate

acceptable instrument performance indicates the need for re-evaluation of the

instrument system. Criteria are listed in Table 8.

9.2.1 The sensitivity requirement is based on the EDLs published in this method. If

laboratory EDLs differ from those listed in Table 2, concentrations of the LPC

standard may be adjusted to be compatible with the laboratory EDLs.

9.2.2 If column or chromatographic performance cannot be met, one or more of the

following remedial actions should be taken. Break off approximately 1 meter

of the injector end of the column and re-install, install a new column, adjust

column flows or modify the oven temperature program.
552.2-13

9.3 INITIAL DEMONSTRATION OF CAPABILITY (IDC)

9.3.1 Calibrate for each analyte of interest as specified in Section 10. Select a

representative fortification concentration for each of the target analytes. 

Concentrations near those in Table 4 are recommended. Prepare 4-7

replicates laboratory fortified blanks by adding an appropriate aliquot of the

primary dilution standard or quality control sample to reagent water. (This

reagent water should contain ammonium chloride at the same concentration

as that specified for samples as per Section 8.1.2.) Analyze the LFBs

according to the method beginning in Section 11.

9.3.2 Calculate the mean percent recovery and the standard deviation of the

recoveries. For each analyte, the mean recovery value, expressed as a

percentage of the true value, must fall in the range of 80-120% and the

relative standard deviation should be less than 20%. For those compounds

that meet these criteria, performance is considered acceptable and sample

analysis may begin. For those compounds that fail these criteria, this

procedure must be repeated using 4-7 fresh samples until satisfactory

performance has been demonstrated. Maintain these data on file to demonstrate initial capabilities.

9.3.3 Furthermore, before processing any samples, the analyst must analyze at least

one laboratory reagent blank to demonstrate that all glassware and reagent

interferences are under control. 

9.3.4 The initial demonstration of capability is used primarily to preclude a

laboratory from analyzing unknown samples via a new, unfamiliar method

prior to obtaining some experience with it. As laboratory personnel gain

experience with this method, the quality of data should improve beyond those

required here.

9.3.5 The analyst is permitted to modify GC columns, GC conditions, internal

standard or surrogate compounds. Each time such method modifications are

made, the analyst must repeat the procedures in Section 9.3.1 through

Section 9.3.4 and Sect. 9.4. 

9.4 METHOD DETECTION LIMIT STUDY (MDL)

9.4.1. Prior to the analysis of any field samples, the method detection limits must be

determined. Initially, estimate the concentration of an analyte which would

yield a peak equal to 5 times the baseline noise and drift. Prepare seven

replicate laboratory fortified blanks at this estimated concentration with

reagent water that contains ammonium chloride at the same concentration as

that specified for samples as per Section 8.1.2. Analyze the LFB's according

to the method beginning in Section 11. 
552.2-14

9.4.2. Calculate the mean recovery and the standard deviation for each analyte. 

Multiply the student's t value at 99% confidence and n-1 degrees of freedom

(3.143 for seven replicates) by this standard deviation to yield a statistical

estimate of the detection limit. This calculated value is the MDL.

9.4.3. Since the statistical estimate is based on the preci- sion of the analysis, an

additional estimate of detection can be determined based upon the noise and

drift of the baseline as well as precision. This estimate is the EDL (Table 2).

9.5 LABORATORY REAGENT BLANKS (LRB) -- Each time a set of samples is extracted or

reagents are changed, a LRB must be analyzed. If the LRB produces an interferant

peak within the retention time window (Section 12.3) of any analyte that would

prevent the determination of that analyte or a peak of concentration greater than the

MDL for that analyte, the analyst must determine the source of contamination and

eliminate the interference before processing samples. Field samples of an extraction

set associated with an LRB that has failed the specified criteria are considered suspect.

NOTE: Reagent water containing ammonium chloride at the same concentrations as in

the samples (Section 8.1.2) is used to prepare the LRB.

9.6 LABORATORY FORTIFIED BLANK (LFB) -- Since this method utilizes procedural

calibration standards, which are fortified reagent water, there is no difference between

the LFB and the continuing calibration check standard. Consequently, the analysis of

an LFB is not required (Section 10.2).

9.7 LABORATORY FORTIFIED SAMPLE MATRIX (LFM)

9.7.1 Chlorinated water supplies will usually contain significant background

concentrations of several method analytes, especially dichloroacetic acid

(DCAA) and trichloroacetic acid (TCAA). The concentrations of these acids

may be equal to or greater than the fortified concentrations. Relatively poor

accuracy and precision may be anticipated when a large background must be

subtracted. For many samples, the concentrations may be so high that

fortification may lead to a final extract with instrumental responses exceeding

the linear range of the electron capture detector. If this occurs, the extract

must be diluted. In spite of these problems, sample sources should be

fortified and analyzed as described below. By fortifying sample matrices and

calculating analyte recoveries, any matrix induced analyte bias is evaluated. 

9.7.2. The laboratory must add known concentrations of analytes to one sample per

extraction set or a minimum of 10% of the samples, whichever is greater. 

The concentrations should be equal to or greater than the background

concentrations in the sample selected for fortification. If the fortification level

is less than the background concentration, recoveries are not reported. Over

time, samples from all routine sample sources should be fortified.
552.2-15

9.7.3 Calculate the mean percent recovery, R, of the concentration for each analyte,

after correcting the total mean measured concentration, A, from the fortified

sample for the back-ground concentration, B, measured in the unfortified

sample, i.e.:

R = 100 (A - B) / C,

 where C is the fortifying concentration. In order for the recoveries to be

considered acceptable, they must fall between 70% and 130% for all the

target analytes. 

9.7.4 If a recovery falls outside of this acceptance range, a matrix induced bias can

be assumed for the respective analyte and the data for that analyte must be

reported to the data user as suspect due to matrix effects.

9.8 ASSESSING SURROGATE RECOVERY

The surrogate analyte is fortified into the aqueous portion of all continuing calibration

standards, samples and laboratory reagent blanks. The surrogate is a means of assessing method performance in every analysis from extraction to final chromatographic

performance. 

9.8.1 When surrogate recovery from a sample, blank or CCC is < 70% or > 130%,

check (1) calculations to locate possible errors, (2) standard solutions for

degradation, (3) contamination, and (4) instrument performance. If those

steps do not reveal the cause of the problem, reanalyze the extract.

9.8.2 If the extract reanalysis meets the surrogate recovery criterion, report only data

for the reanalyzed extract. 

9.8.3 If the extract reanalysis fails the 70-130% recovery criterion, the analyst

should check the calibration by analyzing the most recently acceptable

continuing calibration check standard. If the CCC fails the criteria of Section

10.2.1, recalibration is in order per Section 10.1. If the CCC is acceptable, it

may be necessary to extract another aliquot of sample. If the sample reextract also fails the recovery criterion, report all data for that sample as

suspect.

9.9 ASSESSING THE INTERNAL STANDARD

9.9.1. The analyst must to monitor the IS response (peak area or peak height) of all

injections during each analysis day. A mean IS response should be

determined from the five point calibration curve. The IS response for any run

should not deviate from this mean IS response by more than 30%. It is also

acceptable if the IS response of a injection is within 15% of the daily

continuing calibration standard IS response.
552.2-16

9.9.2 If a deviation greater than this occurs with an individual extract, optimize

instrument performance and inject a second aliquot of that extract.

9.9.2.1 If the reinjected aliquot produces an acceptable internal standard

response, report results for that aliquot.

9.9.2.2 If a deviation of greater than 30% is obtained for the reinjected

extract, the analyst should check the calibration by analyzing the

most recently acceptable CCC. If the CCC fails the criteria of

Section 10.2.1, recalibration is in order per Section 10.1. If the

CCC is acceptable, analysis of the sample should be repeated beginning with Section 11, provided the sample is still available. 

Otherwise, report results obtained from the reinjected extract, but

annotate as suspect.

9.10 QUALITY CONTROL SAMPLE (QCS) -- At least quarterly, analyze a QCS from an

external source. If measured analyte concentrations are not of acceptable accuracy,

check the entire analytical procedure to locate and correct the problem source.

9.11 The laboratory may adapt additional QC practices for use with this method. The

specific practices that are most productive depend upon the needs of the laboratory

and the nature of the samples. For example, field or laboratory duplicates may be analyzed to assess the precision of the environmental measurements or field reagent

blanks may be used to assess contamination of samples under site conditions,

transportation and storage.

10. CALIBRATION AND STANDARDIZATION

10.1 INITIAL CALIBRATION CURVE

10.1.1 Calibration is performed by extracting procedural standards, i.e.; fortified

reagent water, by the procedure set forth in Section 11. A five-point

calibration curve is to be prepared by diluting the primary dilution standard

into MTBE at the appropriate levels. The desired amount of each MTBE

calibration standard is added to separate 40 mL aliquots of reagent water to

produce a calibration curve ranging from the detection limit to approximately

50 times the detection limit. (These MTBE calibration standards should be

prepared so that 20 μL or less of the solution is added the water aliquots.) 

Also, the reagent water used for the procedural standards contains ammonium

chloride at the same concentration as that in the samples as per Section

8.1.2.

10.1.2 Establish GC operating parameters equivalent to the suggested specifications

in Table 1. The GC system must be calibrated using the internal standard (IS)

technique. Other columns or conditions may be used if equivalent or better

performance can be demonstrated.
552.2-17

10.1.2 Five calibration standards are required. The lowest should contain the analytes

at a concentration near to but greater than the MDL (Table 2) for each

compound. The others should be evenly distributed throughout the

concentration range expected in the samples. 

10.1.3 Inject 2 :L of each calibration standard extract and tabulate peak height or

area response and concentration for each analyte and the internal standard.

10.1.4 Generate a calibration curve by plotting the area ratios (Aa/Ais) against the

concentration Ca of the five calibration standards where

Aa is the peak area of the analyte.

Ais is the peak area of the internal standard.

Ca is the concentration of the analyte.

 

This curve can be defined as either first or second order.

Also, the working calibration curve must be verified daily by measurement of

one or more calibration standards (Section 10.2). If the response for any

analyte falls outside the predicted response by more than 30%, the calibration

check must be repeated using a freshly prepared calibration standard. Should

the retest fail, a new calibration curve must be generated.

10.1.5 Alternately, an average relative response factor can be calculated and used for

quantitation. Relative response factors are calculated for each analyte at the

five concentration levels using the equation below:

 (Aa)(Cis)

 RRF = ----------

 (Ais)(Ca)

If the RRF value over the working range is constant (<20% 

RSD), the RRF can be assumed to be invariant and the average RRF used for

calculations. Also, the average RRF must be verified daily by measurement of

one or more calibration standards (Section 10.2). If the RRF for the

continuing calibration standard deviates from the average RRF by more than

30%, the calibration check must be repeated using a freshly prepared

calibration standard. Should the retest fail, a new calibration curve must be

generated.

10.1.6 A data system may be used to collect the chromatographic data, calculate

relative response factors, or calculate linear or second order calibration curves. 
552.2-18

10.2 CONTINUING CALIBRATION CHECK (CCC)

10.2.1 At least one CCC must be extracted with each set of samples. A CCC must be

analyzed at the beginning of each analysis set, after every tenth sample

analysis and after the final sample analysis, to ensure that the instrument is

still within calibration. These checks should be at two different concentration

levels. Calculate analyte recoveries for all target analytes. In order for the

calibration check to be considered valid and subsequently for the preceding

ten samples to be considered acceptable with respect to calibration, recoveries

must fall between 70% and 130% for all the target analytes.

NOTE: Continuing calibration check standards need not necessarily be

different extracts but can be injections from the same extract as long as the

holding time requirements (Sect. 8.3.2) are met.

10.2.2 If this criteria cannot be met, the continuing calibration check standard extract

is re-injected in order to determine if the response deviations observed from

the initial analysis are repeated. If this criteria still cannot be met, a second

CCC should be extracted and analyzed or a CCC that has already been

analyzed and has been found to be acceptable should be run. If this second

CCC fails, then the instrument is considered out of calibration and needs to be

recalibrated.

11. PROCEDURE

11.1 SAMPLE EXTRACTION

11.1.1 Remove the samples from storage (Sect. 8.3.1) and allow them to equilibrate

to room temperature.

11.1.2 Place 40 mL of the water sample into a precleaned 60 mL glass vial with a

teflon-lined screw cap using a graduated cylinder. 

11.1.3 Add 20 :L of surrogate standard (10.0 :g/mL 2,3-dibromopropionic acid in

MTBE per Section 7.5.2). 

NOTE: When fortifying an aqueous sample with either surrogate or target

analytes contained in MTBE, be sure that the needle of the syringe is well

below the level of the water. After injection, cap the sample and invert once. 

This insures that the standard solution is mixed well with the water.

11.1.4 Adjust the pH to less than 0.5 by adding at least 2 mL of concentrated

sulfuric acid. Cap, shake and then check the pH with a pH meter or narrow

range pH paper.

11.1.5 Quickly add approximately 2 g of copper II sulfate pentahydrate and shake

until dissolved. This colors the aqueous phase blue and therefore allows for
552.2-19

the analyst to better distinguish between the aqueous phase and the organic

phase in this micro extraction.

11.1.6 Quickly add 16 g of muffled sodium sulfate and shake for 3 to 5 minutes until

almost all is dissolved. Sodium sulfate is added to increase the ionic strength

of the aqueous phase and thus further drive the haloacetic acids into the

organic phase. The addition of this salt and the copper II sulfate should be

done quickly so that the heat generated from the addition of the acid (Section

11.1.4) will help dissolve the salts. 

11.1.7 Add 4.0 mL MTBE and place on the mechanical shaker for 30 minutes. (If

hand-shaken, two minutes is sufficient if performed vigorously).

11.1.8 Allow the phases to separate for approximately 5 minutes.

11.2 METHYLATION

11.2.1 Using a pasteur pipet, transfer approximately 3 mL of the upper MTBE layer

to a 15 mL graduated conical centrifuge tube.

11.2.2 Add 1 mL 10% sulfuric acid in methanol to each centrifuge tube.

11.2.3 Cap the centrifuge tubes and place in the heating block (or sand bath) at 50°C

and maintain for 2 hr. The vials must fit snugly into the heating block to

ensure proper heat transfer. At this stage, methylation of the method analytes

is attained.

11.2.4 Remove the centrifuge tubes from the heating block (or sand bath) and allow

them to cool before removing the caps.

11.2.5 Add 4 mL saturated sodium bicarbonate solution to each centrifuge tube in 1

mL increments. Exercise caution when adding the solution because the

evolution of CO2 in this neutralization reaction is rather rapid.

11.2.6 Shake each centrifuge tube for 2 minutes. As the neutralization reaction

moves to completion, it is important to continue to exercise caution by venting

frequently to release the evolved CO2.

11.2.7 Transfer exactly 1.0 ml of the upper MTBE layer to an autosampler vial. A

duplicate vial should be filled using the excess extract. 

11.2.8 Add 10 :L of internal standard to the vial to be analyzed. (25 :g/mL 1,2,3-

trichloropropane in MTBE per Section 7.5.1).

11.2.9 Analyze the samples as soon as possible. The sample extract may be stored

up to 7 days if kept at 4°C or less or up to 14 days if kept at -10°C or less. 

Keep the extracts away from light in amber glass vials with Teflon-lined caps.
552.2-20

11.3 GAS CHROMATOGRAPHY

11.3.1 Table 1 summarizes recommended GC operating conditions and retention

times observed using this method. Figure 1 illustrates the performance of the

recommended primary column with the method analytes. Figure 2 illustrates

the performance of the recommended confirmation column with the method

analytes. Concentrations of the analytes of these chromatograms are those

listed in Table 4 for the fortified reagent water samples. Other GC columns or

chromatographic conditions may be used if the requirements of Section 9 are

met.

11.3.2 Calibrate the system (Section 10.1) or verify the existing calibration by

analysis of a CCC daily as described in Section 10.2. 

11.3.3 Inject 2 :L of the sample extract. Record the resulting peak sizes in area or

height units.

11.3.4 If the response for the peak exceeds the working range of the system, dilute

the extract, add an appropriate additional amount of internal standard and

reanalyze. The analyst must not extrapolate beyond the calibration range

established. 

12. DATA ANALYSIS AND CALCULATIONS

12.1 Identify sample components by comparison of retention times to retention data from

the calibration standard analysis. If the retention time of an unknown peak

corresponds, within limits (Section 12.2), to the retention time of a standard

compound, then the identification is considered positive. Calculate analyte concentrations in the samples and reagent blanks from the calibration curves generated in

Section 10.1.

12.2 If an average relative response factor has been calculated (Sect 10.1.5), analyte

concentrations in the samples and reagent blanks are calculated using the following

equation:

 (Aa)(Cis)

 Ca = --------------

 (Ais)(RRF)

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

upon measurements of actual retention time variations of standards over the course of

a day. Three times the standard deviation of a retention time can be used to calculate

a suggested window size for a compound. However, the experience of the analyst

should weigh heavily in the interpretation of chromatogram.
552.2-21

13. METHOD PERFORMANCE

13.1 In a single laboratory, recovery and precision data were obtained at three

concentrations in reagent water (Tables 3 and 4). The MDL and EDL data are given in

Table 2. In addition, recovery and precision data were obtained at a medium

concentration for dechlorinated tap water (Table 5), high ionic strength reagent water

(Table 6) and high humectant ground water (Table 7). 

14. POLLUTION PREVENTION

14.1 This method utilizes a micro-extraction procedure which requires the use of very small

quantities of organic solvents. This feature reduces the hazards involved with the use of

large volumes of potentially harmful organic solvents needed for conventional liquidliquid extractions. This method also uses acidic methanol as the derivatizing reagent. 

14.2 For information about pollution prevention that may be applicable to laboratory

operations consult "Less is Better: Laboratory Chemical Management for Waste

Reduction" available from the American Chemical Society's Department of Government

Relations and Science Policy, 1155 16th Street N.W., Washington, D.C. 20036.

15. WASTE MANAGEMENT

15.1 Due to the nature of this method there is little need for waste management. No large

volumes of solvents or hazardous chemicals are used. The matrices of concern are

finished drinking water or source water. However, the Agency requires that laboratory

waste management practices be conducted consistent with all applicable rules and

regulations, and that laboratories protect the air, water, and land by minimizing and

controlling all releases from fume hoods and bench operations. Also compliance is

required with any sewage discharge permits and regulations, particularly the hazardous

waste identification rules and land disposal restrictions. For further information on

waste management, consult "The Waste Management Manual for Laboratory

Personnel" also available from the American Chemical Society at the address in Sect.

14.2.

16. REFERENCES

1. Quimby, B.D., Delaney, M.F., Uden. P.C. and Barnes, R.M. Anal. Chem. 52, 1980,

pp. 259-263.

2. Uden, P.C. and Miller, J.W., J. Am. Water Works Assoc. 75, 1983, pp. 524-527.

3. Hodgeson, J.W. and Cohen, A.L. and Collins, J.D., "Analytical Methods for Measuring

Organic Chlorination Byproducts", Proceedings Water Quality Technology Conference

(WQTC-16), St. Louis, MO, Nov. 13-17, 1988, American Water Works Association,

Denver, CO, pp. 981-1001. 
552.2-22

4. Fair. P.S., Barth, R.C., "Comparison of the Microextraction Procedure and Method 552

for the Analysis of HAAs and Chlorophenols", Journal AWWA, November, 1992, pp.

94-98.

5. Chinn, R. and Krasner, S. " A Simplified Technique for the Measurement of

Halogenated Organic Acids in Drinking Water by Electron Capture Gas

Chromatography". Presented at the 28th Pacific Conference on Chemistry and

Spectroscopy, Pasadena, CA, October, 1989

6. Hodgeson, J. W., Collins, J. D., and Becker, D. A., "Advanced Techniques for the

Measurement of Acidic Herbicides and Disinfection Byproducts in Aqueous Samples,"

Proceedings of the 14th Annual EPA Conference on Analysis of Pollutants in the

Environment, Norfolk, VA., May 8-9, 1991. Office of Water Publication No. 821-R92-001, U.S. Environmental Protection Agency, Washington, DC, pp 165-194.

7. Shorney, Holly L. and Randtke, Stephen J., "Improved Methods for Haloacetic Acid

Analysis", Proceedings Water Quality Technology Conference, San Francisco, CA,

November 6-10, 1994, American Water Works Association, pp 453-475.

8. Peters, Rund J.B., Erkelens, Corrie, De Leer, Ed W.B. and De Galan, Leo, "The Analysis

of Halogenated Acetic Acids in Dutch Drinking Water", Wat. Res., Vol.25, No.4,

1991, Great Britain, pp 473-477.

9. "Carcinogens-Working with Carcinogens", Publication No. 77-206, Department of

Health, Education, and Welfare, Public Health Service, Center for Disease Control,

National Institute of Occupational Safety and Health, Atlanta, Georgia, August 1977.

10. "OSHA Safety and Health Standards, General Industry", (29CFR1910), OSHA 2206,

Occupational Safety and Health Administration, Washington, D.C. Revised January

1976.

11. "Safety In Academic Chemistry Laboratories", 3rd Edition, American Chemical Society

Publication, Committee on Chemical Safety, Washington, D.C., 1979.

12. Xie, Yuefeng, Reckhow, David A., and Rajan, R.V., "Spontaneous Methylation of

Haloacetic Acids in Methanolic Stock Solutions", Environ. Sci. Technol., Vol.27, No.6,

1993, pp1232-1234.

13. ASTM Annual Book of Standards, Part 31, D3370, "Standard Practice for Sampling

Water", American Society for Testing and Materials, Philadelphia, PA, p. 76, 1980.

14. ASTM Annual Book of Standards, Part 31, D3694, "Standard Practice for Preparation

of Sample Containers and for Preservation", American Society for Testing and Materials,

Philadelphia, PA, p. 679, 1980.

15. Glaser, J. A., Foerst, D. L., McKee, G. D., Quave, S. A. and Budde, W. L., Environ. Sci.

Technol. 15, 1981, pp. 1426-1435.
17. TABLES, DIAGRAMS, FLOWCHARTS, AND VALIDATION DATA

FIGURE 1. ELUTION OF METHOD ANALYTES ON THE PRIMARY COLUMN (DB-5.625) 
FIGURE 2. ELUTION OF METHOD ANALYTES ON THE CONFIRMATION COLUMN (DB-1701) 
552.2-25

TABLE 1. RETENTION DATA AND CHROMATOGRAPHIC CONDITIONS

Retention Time, minutes

Analyte Column A Column B

Monochloroacetic Acid (MCAA)

Monobromoacetic Acid (MBAA)

Dichloroacetic Acid (DCAA)

Dalapon

Trichloroacetic Acid (TCAA)

Bromochloroacetic Acid (BCAA)

1,2,3-Trichloropropane (I.S.)

Dibromoacetic Acid (DBAA)

Bromodichloroacetic Acid (BDCAA)

Chlorodibromoacetic Acid (CDBAA)

2,3-Dibromopropionic Acid (SURR)

Tribromoacetic Acid (TBAA)

13.03

17.15

17.80

19.08

22.67

23.15

23.70

31.38

32.18

41.57

41.77

49.22

13.70

17.33

17.88

17.73

20.73

22.87

22.35

30.27

28.55

38.78

39.72

47.08

Column A: DB-5.625, 30 m x 0.25 mm i.d., 0.25 :m film thickness, Injector Temp. =

200°C, Detector Temp. = 260°C, Helium Linear Velocity = 24 cm/sec. at

35°C, Splitless injection with 30 second delay.

Program: Hold at 35°C for 10 minutes, ramp to 75°C at 5°C/min. and hold

15 minutes, ramp to 100°C at 5°C/min. and hold five minutes, ramp to

135°C at 5°C/min. and hold two minutes.

Column B: DB-1701, 30 m x 0.25 mm i.d., 0.25 :m film thickness, Injector Temp. =

200°C, Detector Temp. = 260°C, Linear Helium Velocity = 25 cm/sec. at

35°C, splitless injection with 30 second delay.

Program: Hold at 35°C for 10 minutes, ramp to 75°C at 5°C/min. and hold

15 minutes, ramp to 100°C at 5°C/min. and hold five minutes, ramp to

135°C at 5°C/min. and hold 0 minutes.
552.2-26

TABLE 2. ANALYTE ACCURACY AND PRECISION DATA AND METHOD DETECTION

LIMITSa

LEVEL 1 IN REAGENT WATER

Analyte

Fortified

Conc.

:g/L

Mean.

Meas.

Conc.

:g/L

Std.

Dev.

:g/L

Rel.

Std.

Dev.

%

Method

Detection

Limitb

:g/L

Estimated

Detection

Limitc

:g/L

MCAA

MBAA

DCAA

Dalapon

TCAA

BCAA

DBAA

BDCAA

CDBAA

TBAA

0.600

0.400

0.600

0.400

0.200

0.400

0.200

0.400

1.00

2.00

0.516

0.527

0.494

0.455

0.219

0.498

0.238

0.357

1.19

1.91

0.087

0.065

0.077

0.038

0.025

0.080

0.021

0.029

0.149

0.261

17

12

16

8.4

11

16

8.8

8.1

12

14

0.273

0.204

0.242

0.119

0.079

0.251

0.066

0.091

0.468

0.820

0.60

0.20

0.24

0.40

0.20

0.25

0.20

0.40

0.75

1.5

a

Produced by analysis of seven aliquots of fortified reagent water.

b

The MDL is a statistical estimate of the detection limit. To determine the MDL for each

analyte, the standard deviation of the mean concentration of the seven replicates is

calculated. This standard deviation is then multiplied by the student's t-value at 99%

confidence and n-1 degrees of freedom (3.143 for seven replicates). The result is the MDL.

c

The EDL is defined as either the MDL or a level of a compound in a sample yielding a peak

in the final extract with a signal to noise (S/N) ratio of approximately five, whichever is

greater.
552.2-27

TABLE 3. ANALYTE ACCURACY AND PRECISION DATAa

LEVEL 2 IN REAGENT WATER

Analyte

Fortified

Conc.

:g/L

Mean.

Meas.

Conc.

:g/L

Std.

Dev.

:g/L

Rel.

Std.

Dev.

%

Mean

Recovery

%

Monochloroacetic Acid

Monobromoacetic Acid

Dichloroacetic Acid

Dalapon

Trichloroacetic Acid

Bromochloroacetic Acid

Dibromoacetic Acid

Bromodichloroacetic Acid

Chlorodibromoacetic Acid

Tribromoacetic Acid

1.50

1.00

1.50

1.00

0.500

1.00

0.500

1.00

2.50

5.00

1.42

1.02

1.27

0.935

0.465

0.869

0.477

1.07

2.62

5.19

0.103

0.051

0.122

0.087

0.048

0.049

0.044

0.098

0.150

0.587

7.3

5.0

9.6

9.3

10

5.6

9.2

9.2

5.7

11

94.7

102

84.7

93.5

93.0

86.9

95.4

107

105

104

a

Produced by analysis of seven aliquots of fortified reagent water.
552.2-28

TABLE 4. ANALYTE ACCURACY AND PRECISION DATAa

LEVEL 4 IN REAGENT WATER

Analyte

Fortified

Conc.

:g/L

Mean.

Meas.

Conc.

:g/L

Std.

Dev.

:g/L

Rel.

Std.

Dev.

%

Mean

Recovery

%

Monochloroacetic Acid

Monobromoacetic Acid

Dichloroacetic Acid

Dalapon

Trichloroacetic Acid

Bromochloroacetic Acid

Dibromoacetic Acid

Bromodichloroacetic Acid

Chlorodibromoacetic Acid

Tribromoacetic Acid

6.00

4.00

6.00

4.00

2.00

4.00

2.00

4.00

10.0

20.0

5.24

4.36

6.89

3.87

1.74

4.33

1.87

3.93

11.4

24.0

0.664

0.475

0.782

0.147

0.144

0.402

0.113

0.377

0.866

1.82

13

11

11

3.8

8.3

9.3

6.0

9.6

7.6

7.6

87.3

109

115

96.8

87.0

108

93.5

98.2

114

120

a

Produced by analysis of seven aliquots of fortified reagent water.
552.2-29

TABLE 5. ANALYTE ACCURACY AND PRECISION DATAa,b

LEVEL 3 IN DECHLORINATED TAP WATERc

Analyte

Background

Conc.

:g/L

Fortified

Conc.

:g/L

Mean

Meas.

Conc.

:g/L

Std.

Dev.

:g/L

Rel.

Std.

Dev.

%

Mean

Rec.

%

Monochloroacetic Acid

Monobromoacetic Acid

Dichloroacetic Acid

Dalapon

Trichloroacetic Acid

Bromochloroacetic Acid

Dibromoacetic Acid

Bromodichloroacetic Acid

Chlorodibromoacetic Acid

Tribromoacetic Acid

<0.6

0.420

0.625

<0.4

0.300

1.23

1.27

0.588

1.23

<2.0

3.00

2.00

3.00

2.00

1.00

2.00

1.00

2.00

5.00

10.0

2.53

2.20

3.77

1.96

1.12

2.91

2.35

2.52

6.36

11.8

0.090

0.034

0.096

0.157

0.167

0.062

0.110

0.388

0.502

1.65

3.6

1.5

2.5

8.0

15

2.1

4.7

15

7.9

14

84.3

89.0

105

98.0

82.0

84.0

108

96.6

103

118

a

 Produced by analysis of seven aliquots of fortified reagent water.

b Background level subtracted.

c

 Chlorinated surface water from a local utility to which ammonium chloride was added as 

the dechlorinating agent.
552.2-30

TABLE 6. ANALYTE ACCURACY AND PRECISION DATAa,b

LEVEL 3 IN HIGH IONIC STRENGTH WATERc

Analyte

Background

Conc.

:g/L

Fortified

Conc.

:g/L

Mean

Meas.

Conc.

:g/L

Std.

Dev.

:g/L

Rel.

Std.

Dev.

%

Mean

Rec.

%

Monochloroacetic Acid

Monobromoacetic Acid

Dichloroacetic Acid

Dalapon

Trichloroacetic Acid

Bromochloroacetic Acid

Dibromoacetic Acid

Bromodichloroacetic Acid

Chlorodibromoacetic Acid

Tribromoacetic Acid

0.761

1.47

1.50

0.675

1.01

2.06

4.36

1.07

2.48

4.63

3.00

2.00

3.00

2.00

1.00

2.00

1.00

2.00

5.00

10.0

3.32

3.19

4.44

2.39

1.75

3.71

5.48

3.37

7.94

17.2

0.429

0.099

0.264

0.259

0.110

0.269

0.255

0.308

1.00

1.55

13

3.1

5.9

11

6.3

7.3

4.7

9.1

13

9.0

85.3

86.0

98.0

85.8

74.0

82.5

112

115

109

126

a

Produced by analysis of seven aliquots of fortified reagent water.

b

Background level subtracted.

c

Chlorinated ground water from a water source displaying a hardness of 460 mg/L as

CaCO3.
552.2-31

TABLE 7. ANALYTE ACCURACY AND PRECISION DATAa

LEVEL 3 IN HIGH HUMIC CONTENT GROUND WATERb

Analyte

Background

Conc.

:g/L

Fortified

Conc.

:g/L

Mean

Meas.

Conc.

:g/L

Std.

Dev.

:g/L

Rel.

Std.

Dev.

%

Mean

Rec.

%

Monochloroacetic Acid

Monobromoacetic Acid

Dichloroacetic Acid

Dalapon

Trichloroacetic Acid

Bromochloroacetic Acid

Dibromoacetic Acid

Bromodichloroacetic Acid

Chlorodibromoacetic Acid

Tribromoacetic Acid

<0.6

<0.4

<0.6

<0.4

<0.2

<0.4

<0.2

<0.4

<1.0

<2.0

3.00

2.00

3.00

2.00

1.00

2.00

1.00

2.00

5.00

10.0

2.91

1.99

2.88

2.00

0.618

1.82

0.715

1.99

5.50

9.67

0.082

0.105

0.104

0.227

0.053

0.059

0.020

0.164

0.218

1.13

2.8

5.3

3.6

11

8.6

3.2

2.8

8.2

4.0

12

97.0

99.5

96.0

100.0

61.8

91.0

71.5

99.5

110.0

96.7

a

Produced by analysis of seven aliquots of fortified reagent water.

b

Background level subtracted.
552.2-32

TABLE 8. LABORATORY PERFORMANCE CHECK SOLUTION

Parameter Analyte

Conc.

:g/mL

in

MTBE

Acceptance

Criteria

INSTRUMENT

SENSITIVITY

CHROMATOGRAPHIC

PERFORMANCE

COLUMN

PERFORMANCE

MCAA

BCAA

CDBAA

SURROGATE (2,3-DBPA)

0.006

0.004

0.010

0.010

DETECTION OF ANALYTE;

S/Na

 >3

PGFb

 BETWEEN 0.80 AND

1.15

RESOLUTIONc

 >0.50

a

S/N = a ratio of peak signal to baseline noise.

 peak signal - measured as height of peak.

 baseline noise - measured as maximum deviation in baseline (in units of height)

 over a width equal to the width of the base of the peak.

b

PGF -- Peak Gaussian factor

where: W1/2 = the peak width at half height in seconds

W1/10 = the peak width in seconds at one-tenth height (in seconds)

b

Resolution between the two peaks as defined by the equation:

where: t = the difference in elution times between the two peaks

Wave = the average peak width of the two peaks (measurements take

at baseline)

This is a measure of the degree of separation of two peaks under specific chromatographic

conditions.
552.2-33

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