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

SIGNIFICANCE AND USE
Chlorinated phenoxyacid herbicides, and other organic acids are used extensively for weed control. Esters and salts of 2,4-D and silvex have been used as aquatic herbicides in lakes, streams, and irrigation canals. Phenoxy acid herbicides can be toxic even at low concentrations. For example, the 96 h, TLm for silvex is 2.4 mg/L for bluegills (1)9 . These reasons make apparent the need for a standard test method for such compounds in water.
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:AnalyteChemical Abstract Services Registry NumberBentazon25057-89-02,4-D94-75-72,4-DB94-82-6DCPA acid metabolites 2Dicamba1918-00-93,5-Dichlorobenzoic acid51-36-5Dichlorprop120-36-55-Hydroxydicamba7600-50-2Pentachlorophenol (PCP)87-86-5Picloram1918-02-12,4,5-T93-76-52,4,5-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 quantitation 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 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.8 This standard does not purport to address all of the safety concerns, 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 warning statements, see Sections 6 ,8 ,9 and 10.

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Historical
Publication Date
09-Jun-2003
Current Stage
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ASTM D5317-98(2003)e1 - 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 superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
´1
Designation: D5317 – 98 (Reapproved 2003)
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 D5317; 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 (´) indicates an editorial change since the last revision or reapproval.
´ NOTE—Warning notes were editorially moved into the standard text in August 2003.
1. Scope ableresultswiththistestmethodusingtheproceduredescribed
in 19.3. It is the user’s responsibility to ensure the validity of
1.1 This test method covers a gas chromatographic proce-
this test method for waters of untested matrices.
dure for the quantitative determination of selected chlorinated
1.5 Analytes that are not separated chromatographically,
acids and other acidic herbicides in water. Similar chemicals
that is, which have very similar retention times, cannot be
may also be determined by this test method, but it is the user’s
individually identified and measured in the same calibration
responsibility to verify the applicability of this test method to
mixture or water sample unless an alternate technique for
any compounds not listed in this scope. The acid form of the
identification and quantitation exists (16.6, 16.7, and 16.8).
following compounds were interlaboratory tested using this
1.6 When this test method is used to analyze unfamiliar
test method, and the results were found acceptable:
samples for any or all of the analytes given in 1.1, analyte
Analyte Chemical Abstract Services
identifications must be confirmed by at least one additional
Registry Number
Bentazon 25057-89-0
qualitative technique.
2,4-D 94-75-7
1.7 The values stated in SI units are to be regarded as the
2,4-DB 94-82-6
standard. The values given in parentheses are for information
DCPA acid metabolites
Dicamba 1918-00-9
only.
3,5-Dichlorobenzoic acid 51-36-5
1.8 This standard does not purport to address all of the
Dichlorprop 120-36-5
5-Hydroxydicamba 7600-50-2 safety concerns, if any, associated with its use. It is the
Pentachlorophenol (PCP) 87-86-5
responsibility of the user of this standard to establish appro-
Picloram 1918-02-1
priate safety and health practices and determine the applica-
2,4,5-T 93-76-5
2,4,5-TP (Silvex) 93-72-1 bility of regulatory limitations prior to use. For specific
warning statements, see Sections 6, 8, 9, and 10.
1.2 This test method may be applicable to the determination
ofsaltsandestersofanalytecompounds.Theformofeachacid
2. Referenced Documents
is not distinguished by this test method. Results are calculated
2.1 ASTM Standards:
and reported for each listed analyte as the total free acid.
D1129 Terminology Relating to Water
1.3 Thistestmethodhasbeenvalidatedinaninterlaboratory
D1193 Specification for Reagent Water
testforreagentwaterandfinishedtapwater.Theanalystshould
D2777 Practice for Determination of Precision and Bias of
recognize that precision and bias reported in Section 18 may
Applicable Test Methods of Committee D19 on Water
not be applicable to other waters.
D3370 Practices for Sampling Water from Closed Conduits
1.4 This test method is restricted to use by or under the
D3856 Guide for Good Laboratory Practices in Laborato-
supervision of analysts experienced in the use of gas chroma-
ries Engaged in Sampling and Analysis of Water
tography (GC) and in the interpretation of gas chromatograms.
D4210 Practice for Intralaboratory Quality Control Proce-
Each analyst must demonstrate the ability to generate accept-
dures and a Discussion on Reporting Low-Level Data
D5789 Practice for Writing Quality Control Specifications
This test method is under the jurisdiction of ASTM Committee D19 on Water
andisthedirectresponsibilityofSubcommitteeD19.06onMethodsforAnalysisfor
Organic Substances in Water. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved June 10, 2003. Published August 2003. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1992. Last previous edition approved in 1998 as D5317 – 93 (1998). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/D5317-98R03E01. the ASTM website.
2 4
DCPA monoacid and diacid metabolites are included in the scope of this test Withdrawn. The last approved version of this historical standard is referenced
method; DCPA diacid metabolite is used for validation studies. on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
´1
D5317 – 98 (2003)
4 8
for Standard Test Methods for Organic Constituents for silvex is 2.4 mg/L for bluegills (1) . These reasons make
2.2 EPA Standard: apparent the need for a standard test method for such com-
Method 515.1, Revision4.0,MethodsfortheDetermination pounds in water.
of Organic Compounds in Drinking Water
6. Interferences
2.3 OSHA Standard:
6.1 Method interferences may be caused by contaminants in
29 CFR 1910 OSHA Safety and Health Standards, General
solvents, reagents, glassware and other sample processing
Industry
apparatus that lead to discrete artifacts or elevated baselines in
3. Terminology gas chromatograms. All reagents and apparatus must be rou-
tinely demonstrated to be free from interferences under the
3.1 Definitions—For definitions of terms used in this test
conditions of the analysis by running laboratory reagent blanks
method, refer to Terminology D1129.
as described in 19.2.
3.2 Definitions of Terms Specific to This Standard:
6.1.1 Glassware must be scrupulously cleaned (2). Clean all
3.2.1 internal standard—a pure analyte(s) added to a solu-
glassware as soon as possible after use by thoroughly rinsing
tion in known amount(s) and used to measure the relative
with the last solvent used in it. Follow by washing with hot
responses of other method analytes and surrogates that are
water and detergent and thoroughly rinsing with dilute acid,
components of the same solution.
tap, and reagent water. Drain dry, and heat in an oven or muffle
3.2.1.1 Discussion—The internal standard must be an ana-
furnace at 400°C for 1 h. Do not heat volumetric ware.
lyte that is not a sample component.
Thorough rinsing with acetone may be substituted for the
3.2.2 surrogate analyte—a pure analyte(s), which is ex-
heating. After drying and cooling, seal and store glassware in
tremelyunlikelytobefoundinanysample,andwhichisadded
a clean environment to prevent any accumulation of dust or
to a sample aliquot in known amount(s) before extraction and
other contaminants. Store inverted or capped with aluminum
is measured with the same procedures used to measure other
foil. Thermally stable materials such as PCBs may not be
sample components.
eliminated by this treatment.
3.2.2.1 Discussion—Thepurposeofasurrogateanalyteisto
6.1.2 The use of high purity reagents and solvents helps to
monitor method performance with each sample.
minimize interference problems. Purification of solvents by
distillation in all-glass systems may be required. (Warning—
4. Summary of Test Method
When a solvent is purified, stabilizers added by the manufac-
4.1 The compounds listed in 1.1, in water samples, are
turer are removed, thus potentially making the solvent hazard-
converted into sodium salts by adjusting the pH to 12 with
ous. Also, when a solvent is purified, preservatives added by
sodium hydroxide solution (240 g/L) and shaking for 1 h.
the manufacturer are removed, thus potentially reducing the
Extraneous neutral material is removed by extraction with
shelf-life.)
methylene chloride. The sample is acidified, the acids are
6.2 The acid forms of the analytes are strong organic acids
extracted with ethyl ether and converted to methyl esters using
that react readily with alkaline substances and can be lost
diazomethane.After the excess reagent is removed, the methyl
during sample preparation. Glassware and glass wool must be
estersaredeterminedbycapillarycolumnGCusinganelectron
acid-rinsed with hydrochloric acid (1 + 9) and the sodium
capture (EC) detector. Other detection systems, such as micro-
sulfatemustbeacidifiedwithsulfuricacidpriortousetoavoid
coulometric and electrolytic conductivity, are not as sensitive
analyte loses due to adsorption.
as EC for measurement of chlorinated acid esters but are more
6.3 Organic acids and phenols, especially chlorinated com-
specific and less subject to interferences. A mass spectrometer
pounds, cause the most direct interference with the determina-
may also be used as a detector.
tion.Alkalinehydrolysisandsubsequentextractionofthebasic
4.2 This test method provides a magnesium silicate
sample removes many chlorinated hydrocarbons and phthalate
cleanupproceduretoaidintheeliminationofinterferencesthat
esters that might otherwise interfere with the electron capture
may be present.
analysis.
6.4 Interferences by phthalate esters can pose a major
5. Significance and Use
problem in pesticide analysis when using the ECD. These
5.1 Chlorinated phenoxyacid herbicides, and other organic
compounds generally appear in the chromatogram as large
acids are used extensively for weed control. Esters and salts of
peaks. Common flexible plastics contain varying amounts of
2,4-D and silvex have been used as aquatic herbicides in lakes,
phthalates, which are easily extracted or leached during labo-
streams, and irrigation canals. Phenoxy acid herbicides can be
ratory operations. Cross contamination of clean glassware
toxic even at low concentrations. For example, the 96 h, TL
m
routinely occurs when plastics are handled during extraction
steps, especially when solvent-wetted surfaces are handled.
Interferences from phthalates can best be minimized by avoid-
EPA/600/4-88/039, 1989, available from Environmental Monitoring Systems
ing the use of plastics in the laboratory. Exhaustive purification
Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH 45268.
of reagents and glassware may be required to eliminate
AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.
background phthalate contamination (3).
Florisil, a trademark of, and available from, Floridin Co., 2 Gateway Center,
Pittsburgh, PA15222, or its equivalent, has been found satisfactory for this purpose.
The boldface numbers in parentheses refer to the list of references at the end of
this test method.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
´1
D5317 – 98 (2003)
6.5 Interfering contamination may occur when a sample
containing low concentrations of analytes is analyzed imme-
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
(MTBE) can minimize sample cross contamination. After
analysis of a sample containing high concentrations of ana-
lytes, one or more injections of MTBE should be made to
ensure that accurate values are obtained for the next sample.
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
FIG. 1 Gaseous Diazomethane Generator
contained in the same solvent. The solvent for working
standards must be the same as the final solvent used in sample
columns and all required accessories including syringes, ana-
preparation. If this is not the case, chromatographic compara-
lytical columns, gases, detector, and stripchart recorder.Adata
bility of standards to sample may be affected.
systemisrecommendedformeasuringpeakareas.Table1 lists
7. Apparatus and Equipment retention times observed for test method analytes using the
columns and analytical conditions described below.
7.1 Sample Bottle—Borosilicate amber, 1-L volume with
7.7.1 Column 1 (Primary Column), 30-m long by 0.25-mm
graduations, fitted with screw caps lined with TFE-
inside diameter (I.D.) DB-5 bonded fused silica column,
fluorocarbon. Protect samples from light. The container must
0.25-µm film thickness. Establish helium carrier gas flow at 30
be washed and dried as described in 6.1.1 before use to
cm/s linear velocity and program oven temperature from 60°C
minimize contamination. Cap liners are cut to fit from sheets
to 300°C at 4°C/m. Data presented in this test method were
and extracted with methanol overnight prior to use.
obtained using this column (Table 1). The injection volume is
7.2 Glassware.
2 µL splitless mode with 45 s delay. The injector temperature
7.2.1 Separatory funnel, 2000-mL, with TFE-fluorocarbon
is 250°C and the detector is 320°C. Alternative columns may
stopcocks, ground glass or TFE-fluorocarbon stoppers.
be used in accordance with the provisions described in 19.3.
7.2.2 Tumbler bottle, 1.7-L with TFE-fluorocarbon lined
screw cap. Cap liners are cut to fit from sheets and extracted
with methanol overnight prior to use.
TABLE 1 Retention Times and Estimated Method Detection
Limits for Method Analytes
7.2.3 Concentrator tube, Kuderna-Danish (K-D), 10 or
A
25-mL, graduated. Calibration must be checked at the volumes Retention Time (min)
B
Analyte CAS No. EDL
employed in the procedure. Ground-glass stoppers are used to
Primary Confirmation
prevent evaporation of extracts.
3,5-Dichlorobenzoic 51-36-5 18.6 17.7 0.061
7.2.4 Evaporative flask, K-D, 500-mL.Attach to concentra- acid
DCAA (surrogate) 19719-28-9 22.0 14.9 .
tor tube with springs.
Dicamba 1918-00-9 22.1 22.6 0.081
7.2.5 Snyder column, K-D, three ball macro.
Dichlorprop 120-36-5 25.0 25.6 0.26
7.2.6 Snyder column, K-D, two ball micro. 2,4-D 94-75-7 25.5 27.0 0.2
DBOB (int. std.) 10386-84-2 27.5 27.6 .
7.2.7 Flask, round bottom, 500-mLwith 24/40 ground glass
Pentachlorophenol 87
...

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