Standard Test Method for Determination of Chlorinated Organic Acid Compounds in Water by Gas Chromatography with an Electron Capture Detector

SCOPE
1.1 This test method covers a gas chromatographic procedure for the quantitative determination of selected chlorinated acids and other acidic herbicides in water. Similar chemicals may also be determined by this test method, but it is the user's responsibility to verify the applicability of this test method to any compounds not listed in this scope. The acid form of the following compounds were interlaboratory tested using this test method, and the results were found acceptable:  Analyte Chemical Abstract Services Registry Number Bentazon 25057-89-0 2,4-D 94-75-7 2,4-DB 94-82-6 DCPA acid metabolites 2 Dicamba 1918-00-9 3,5-Dichlorobenzoic acid 51-36-5 Dichlorprop 120-36-5 5-Hydroxydicamba 7600-50-2 Pentachlorophenol (PCP) 87-86-5 Picloram 1918-02-1 2,4,5-T 93-76-5 2,4,5-TP (Silvex) 93-72-1
1.2 This test method may be applicable to the determination of salts and esters of analyte compounds. The form of each acid is not distinguished by this test method. Results are calculated and reported for each listed analyte as the total free acid.
1.3 This test method has been validated in an interlaboratory test for reagent water and finished tap water. The analyst should recognize that precision and bias reported in Section 18 may not be applicable to other waters.
1.4 This test method is restricted to use by or under the supervision of analysts experienced in the use of gas chromatography (GC) and in the interpretation of gas chromatograms. Each analyst must demonstrate the ability to generate acceptable results with this test method using the procedure described in 19.3. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.
1.5 Analytes that are not separated chromatographically, that is, which have very similar retention times, cannot be individually identified and measured in the same calibration mixture or water sample unless an alternate technique for identification and quantization exists (16.6, 16.7, and 16.8).
1.6 When this test method is used to analyze unfamiliar samples for any or all of the analytes given in 1.1, analyte identifications must be confirmed by at least one additional qualitative technique.
1.7 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see Notes 1, 4, and 5, and Section 9.

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Publication Date
09-Dec-1998
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ASTM D5317-98 - Standard Test Method for Determination of Chlorinated Organic Acid Compounds in Water by Gas Chromatography with an Electron Capture Detector
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5317 – 98
Standard Test Method for
Determination of Chlorinated Organic Acid Compounds in
Water by Gas Chromatography with an Electron Capture
Detector
This standard is issued under the fixed designation D 5317; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope in 19.3. It is the user’s responsibility to ensure the validity of
this test method for waters of untested matrices.
1.1 This test method covers a gas chromatographic proce-
1.5 Analytes that are not separated chromatographically,
dure for the quantitative determination of selected chlorinated
that is, which have very similar retention times, cannot be
acids and other acidic herbicides in water. Similar chemicals
individually identified and measured in the same calibration
may also be determined by this test method, but it is the user’s
mixture or water sample unless an alternate technique for
responsibility to verify the applicability of this test method to
identification and quantitation exists (16.6, 16.7, and 16.8).
any compounds not listed in this scope. The acid form of the
1.6 When this test method is used to analyze unfamiliar
following compounds were interlaboratory tested using this
2 samples for any or all of the analytes given in 1.1, analyte
test method, and the results were found acceptable:
identifications must be confirmed by at least one additional
Analyte Chemical Abstract Services
qualitative technique.
Registry Number
Bentazon 25057-89-0
1.7 This standard does not purport to address all of the
2,4-D 94-75-7
safety concerns, if any, associated with its use. It is the
2,4-DB 94-82-6
responsibility of the user of this standard to establish appro-
DCPA acid metabolites
Dicamba 1918-00-9
priate safety and health practices and determine the applica-
3,5-Dichlorobenzoic acid 51-36-5
bility of regulatory limitations prior to use. For specific
Dichlorprop 120-36-5
precautionary statements, see Note 1, Note 4, and Note 5, and
5-Hydroxydicamba 7600-50-2
Pentachlorophenol (PCP) 87-86-5
Section 9.
Picloram 1918-02-1
2,4,5-T 93-76-5
2. Referenced Documents
2,4,5-TP (Silvex) 93-72-1
2.1 ASTM Standards:
1.2 This test method may be applicable to the determination
D 1129 Terminology Relating to Water
of salts and esters of analyte compounds. The form of each acid
D 1193 Specification for Reagent Water
is not distinguished by this test method. Results are calculated
D 2777 Practice for Determination of Precision and Bias of
and reported for each listed analyte as the total free acid.
Applicable Methods of Committee D-19 on Water
1.3 This test method has been validated in an interlaboratory
D 3370 Practices for Sampling Water from Closed Con-
test for reagent water and finished tap water. The analyst should
duits
recognize that precision and bias reported in Section 18 may
D 3856 Guide for Good Laboratory Practices in Laborato-
not be applicable to other waters.
ries Engaged in Sampling and Analysis of Water
1.4 This test method is restricted to use by or under the
D 4210 Practice for Interlaboratory Quality Control Proce-
supervision of analysts experienced in the use of gas chroma-
dures and a Discussion of Reporting Low-Level Data
tography (GC) and in the interpretation of gas chromatograms.
D 5789 Practice for Writing Quality Control Specifications
Each analyst must demonstrate the ability to generate accept-
for Standard Test Methods for Organic Constituents
able results with this test method using the procedure described
2.2 EPA Standard:
Method 515.1, Revision 4.0, Methods for the Determination
of Organic Compounds in Drinking Water
This test method is under the jurisdiction of ASTM Committee D-19 on Water
and is the direct responsibility of Subcommittee D19.06 on Methods for Analysis for
Organic Substances in Water.
Current edition approved Dec. 10, 1998. Published March 1999. Originally
published as D 5317 – 92. Last previous edition D 5317 – 93. Annual Book of ASTM Standards, Vol 11.01.
2 4
DCPA monoacid and diacid metabolites are included in the scope of this test EPA/600/4-88/039, 1989, available from Environmental Monitoring Systems
method; DCPA diacid metabolite is used for validation studies. Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH 45268.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5317 – 98
2.3 OSHA Standard: apparatus that lead to discrete artifacts or elevated baselines in
29 CFR 1910 OSHA Safety and Health Standards, General
gas chromatograms. All reagents and apparatus must be rou-
Industry tinely demonstrated to be free from interferences under the
conditions of the analysis by running laboratory reagent blanks
3. Terminology
as described in 19.2.
3.1 Definitions—For definitions of terms used in this test
6.1.1 Glassware must be scrupulously cleaned (2). Clean all
method, refer to Terminology D 1129.
glassware as soon as possible after use by thoroughly rinsing
3.2 Definitions of Terms Specific to This Standard:
with the last solvent used in it. Follow by washing with hot
3.2.1 internal standard—a pure analyte(s) added to a solu-
water and detergent and thoroughly rinsing with dilute acid,
tion in known amount(s) and used to measure the relative
tap, and reagent water. Drain dry, and heat in an oven or muffle
responses of other method analytes and surrogates that are
furnace at 400°C for 1 h. Do not heat volumetric ware.
components of the same solution.
Thorough rinsing with acetone may be substituted for the
3.2.1.1 Discussion—The internal standard must be an ana-
heating. After drying and cooling, seal and store glassware in
lyte that is not a sample component.
a clean environment to prevent any accumulation of dust or
3.2.2 surrogate analyte—a pure analyte(s), which is ex-
other contaminants. Store inverted or capped with aluminum
tremely unlikely to be found in any sample, and which is added
foil. Thermally stable materials such as PCBs may not be
to a sample aliquot in known amount(s) before extraction and
eliminated by this treatment.
is measured with the same procedures used to measure other
6.1.2 The use of high purity reagents and solvents helps to
sample components.
minimize interference problems. Purification of solvents by
3.2.2.1 Discussion—The purpose of a surrogate analyte is to
distillation in all-glass systems may be required.
monitor method performance with each sample.
NOTE 1—Warning: When a solvent is purified, stabilizers added by the
4. Summary of Test Method
manufacturer are removed, thus potentially making the solvent hazardous.
4.1 The compounds listed in 1.1, in water samples, are
Also, when a solvent is purified, preservatives added by the manufacturer
converted into sodium salts by adjusting the pH to 12 with
are removed, thus potentially reducing the shelf-life.
sodium hydroxide solution (240 g/L) and shaking for 1 h.
6.2 The acid forms of the analytes are strong organic acids
Extraneous neutral material is removed by extraction with
that react readily with alkaline substances and can be lost
methylene chloride. The sample is acidified, the acids are
during sample preparation. Glassware and glass wool must be
extracted with ethyl ether and converted to methyl esters using
acid-rinsed with hydrochloric acid (1 + 9) and the sodium
diazomethane. After the excess reagent is removed the methyl
sulfate must be acidified with sulfuric acid prior to use to avoid
esters are determined by capillary column GC using an electron
analyte loses due to adsorption.
capture (EC) detector. Other detection systems, such as micro-
6.3 Organic acids and phenols, especially chlorinated com-
coulometric and electrolytic conductivity, are not as sensitive
pounds, cause the most direct interference with the determina-
as EC for measurement of chlorinated acid esters but are more
tion. Alkaline hydrolysis and subsequent extraction of the basic
specific and less subject to interferences. A mass spectrometer
sample removes many chlorinated hydrocarbons and phthalate
may also be used as a detector.
esters that might otherwise interfere with the electron capture
4.2 This test method provides a magnesium silicate
analysis.
cleanup procedure to aid in the elimination of interferences that
6.4 Interferences by phthalate esters can pose a major
may be present.
problem in pesticide analysis when using the ECD. These
5. Significance and Use
compounds generally appear in the chromatogram as large
5.1 Chlorinated phenoxyacid herbicides, and other organic
peaks. Common flexible plastics contain varying amounts of
acids are used extensively for weed control. Esters and salts of
phthalates, which are easily extracted or leached during labo-
2,4-D and silvex have been used as aquatic herbicides in lakes,
ratory operations. Cross contamination of clean glassware
streams, and irrigation canals. Phenoxy acid herbicides can be
routinely occurs when plastics are handled during extraction
toxic even at low concentrations. For example, the 96 h, TL
steps, especially when solvent-wetted surfaces are handled.
m
for silvex is 2.4 mg/L for bluegills (1). These reasons make
Interferences from phthalates can best be minimized by avoid-
apparent the need for a standard test method for such com- ing the use of plastics in the laboratory. Exhaustive purification
pounds in water.
of reagents and glassware may be required to eliminate
background phthalate contamination (3).
6. Interferences
6.5 Interfering contamination may occur when a sample
6.1 Method interferences may be caused by contaminants in
containing low concentrations of analytes is analyzed imme-
solvents, reagents, glassware and other sample processing
diately following a sample containing relatively high concen-
trations of analytes. Between-sample rinsing of the sample
syringe and associated equipment with methyl-t-butyl-ether
Available from Superintendent of Documents, U.S. Government Printing
Office, Washington, DC 20402.
(MTBE) can minimize sample cross contamination. After
Florisil, a trademark of, and available from, Floridin Co., 2 Gateway Center,
analysis of a sample containing high concentrations of ana-
Pittsburgh, PA 15222, or its equivalent, has been found satisfactory for this purpose.
7 lytes, one or more injections of MTBE should be made to
The boldface numbers in parentheses refer to the list of references at the end of
this test method. ensure that accurate values are obtained for the next sample.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5317 – 98
6.6 Matrix interferences may be caused by contaminants
that are coextracted from the sample. Also, note that all
analytes listed in Table 1 are not resolved from each other on
any one column, that is, one analyte of interest may be an
interferent for another analyte of interest. The extent of matrix
interferences will vary considerably from source to source,
depending upon the water sampled. The procedures in Section
16 can be used to overcome many of these interferences.
Positive identifications should be confirmed. See 16.6, 16.7,
and 16.8.
6.7 It is important that samples and working standards be
contained in the same solvent. The solvent for working
standards must be the same as the final solvent used in sample
preparation. If this is not the case, chromatographic compara-
bility of standards to sample may be affected.
7. Apparatus and Equipment
7.1 Sample Bottle— Borosilicate amber, 1-L volume with
graduations, fitted with screw caps lined with TFE-
fluorocarbon. Protect samples from light. The container must
FIG. 1 Gaseous Diazomethane Generator
be washed and dried as described in 6.1.1 before use to
minimize contamination. Cap liners are cut to fit from sheets
TABLE 1 Retention Times and Estimated Method Detection
and extracted with methanol overnight prior to use.
Limits for Method Analytes
7.2 Glassware.
A
Retention Time (min)
B
Analyte CAS No. EDL
7.2.1 Separatory funnel, 2000-mL, with TFE-fluorocarbon
Primary Confirmation
stopcocks, ground glass or TFE-fluorocarbon stoppers.
3,5-Dichlorobenzoic 51-36-5 18.6 17.7 0.061
7.2.2 Tumbler bottle, 1.7-L with TFE-fluorocarbon lined
acid
screw cap. Cap liners are cut to fit from sheets and extracted
DCAA (surrogate) 19719-28-9 22.0 14.9 .
Dicamba 1918-00-9 22.1 22.6 0.081
with methanol overnight prior to use.
Dichlorprop 120-36-5 25.0 25.6 0.26
7.2.3 Concentrator tube, Kuderna-Danish (K-D), 10 or
2,4-D 94-75-7 25.5 27.0 0.2
25-mL, graduated. Calibration must be checked at the volumes
DBOB (int. std.) 10386-84-2 27.5 27.6 .
Pentachlorophenol 87-86-5 28.3 27.0 0.076
employed in the procedure. Ground-glass stoppers are used to
2,4,5-TP 93-72-1 29.7 29.5 0.075
prevent evaporation of extracts.
5-Hydroxydicamba 7600-50-2 30.0 30.7 0.04
7.2.4 Evaporative flask, K-D, 500-mL. Attach to concentra-
2,4,5-T 93-76-5 30.5 30.9 0.08
2,4-DB 94-82-6 32.2 32.2 0.8
tor tube with springs.
Bentazon 25057-89-0 33.3 34.6 0.2
7.2.5 Snyder column, K-D, three ball macro.
Picloram 1918-02-1 34.4 37.5 0.14
7.2.6 Snyder column, K-D, two ball micro.
DCPA acid . 35.8 37.8 0.02
C
metabolites
7.2.7 Flask, round bottom, 500-mL with 24/40 ground glass
A
Columns and analytical conditions are described in 7.7.1 and 7.7.2
joint.
B
Estimated method detection limit, μg/L, determined from 7 replicate analyses
7.2.8 Vials, glass, 5 to 10-mL capacity with TFE-
of a reagent water fortified with analyte at a concentration level yielding signal-to-
fluorocarbon lined screw cap.
noise of 5:1. EDL is defined as the standard deviation 3 student’s t (99 % C.I., n-1
degrees of freedom).
7.3 Boiling Stone, TFE-fluorocarbon.
C
DCPA monoacid and diacid metabolites are included in the scope of this test
7.4 Water Bath, heated, capable of temperature control (6
method; DCPA diacid metabolite is used for validation studies.
2°C). The bath should be used in a hood.
7.5 Diazomethane Generator—Assemble from two 20 by
155-mm test tubes, two neoprene rubber stoppers, and a source to 300°C at 4°C/m. Data presented in this test method were
of nitrogen as shown in Fig. 1. obtained using this column (Table 1). The injection volume is
2 μL splitless mode with 45 s delay. The injector temperature
7.6 Glass Woo
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