1、Designation: D5317 98 (Reapproved 2011)Standard Test Method forDetermination of Chlorinated Organic Acid Compounds inWater by Gas Chromatography with an Electron CaptureDetector1This standard is issued under the fixed designation D5317; the number immediately following the designation indicates the
2、year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a gas chromatographic proce-
3、dure for the quantitative determination of selected chlorinatedacids and other acidic herbicides in water. Similar chemicalsmay also be determined by this test method, but it is the usersresponsibility to verify the applicability of this test method toany compounds not listed in this scope. The acid
4、 form of thefollowing compounds were interlaboratory tested using thistest method, and the results were found acceptable:2Analyte Chemical Abstract ServicesRegistry NumberBentazon 25057-89-02,4-D 94-75-72,4-DB 94-82-6DCPA acid metabolites2Dicamba 1918-00-93,5-Dichlorobenzoic acid 51-36-5Dichlorprop
5、120-36-55-Hydroxydicamba 7600-50-2Pentachlorophenol (PCP) 87-86-5Picloram 1918-02-12,4,5-T 93-76-52,4,5-TP (Silvex) 93-72-11.2 This test method may be applicable to the determinationof salts and esters of analyte compounds. The form of each acidis not distinguished by this test method. Results are c
6、alculatedand reported for each listed analyte as the total free acid.1.3 This test method has been validated in an interlaboratorytest for reagent water and finished tap water. The analyst shouldrecognize that precision and bias reported in Section 18 maynot be applicable to other waters.1.4 This te
7、st method is restricted to use by or under thesupervision of analysts experienced in the use of gas chroma-tography (GC) and in the interpretation of gas chromatograms.Each analyst must demonstrate the ability to generate accept-able results with this test method using the procedure describedin 19.3
8、. It is the users responsibility to ensure the validity ofthis test method for waters of untested matrices.1.5 Analytes that are not separated chromatographically,that is, which have very similar retention times, cannot beindividually identified and measured in the same calibrationmixture or water s
9、ample unless an alternate technique foridentification and quantitation exists (16.6, 16.7, and 16.8).1.6 When this test method is used to analyze unfamiliarsamples for any or all of the analytes given in 1.1, analyteidentifications must be confirmed by at least one additionalqualitative technique.1.
10、7 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro
11、-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specificwarning statements, see Sections 6, 8, 9, and 10.2. Referenced Documents2.1 ASTM Standards:3D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD2777 Practice
12、for Determination of Precision and Bias ofApplicable Test Methods of Committee D19 on WaterD3370 Practices for Sampling Water from Closed ConduitsD3856 Guide for Good Laboratory Practices in Laborato-ries Engaged in Sampling and Analysis of WaterD4210 Practice for Intralaboratory Quality Control Pro
13、ce-dures and a Discussion on Reporting Low-Level Data4D5789 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Organic Constituents42.2 EPA Standard:1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommitte
14、e D19.06 on Methods forAnalysis forOrganic Substances in Water.Current edition approved May 1, 2011. Published June 2011. Originallyapproved in 1992. Last previous edition approved in 2003 as D5317 93 (2003)1.DOI: 10.1520/D5317-98R11.2DCPA monoacid and diacid metabolites are included in the scope of
15、 this testmethod; DCPA diacid metabolite is used for validation studies.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe AS
16、TM website.4Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Method 515.1, Revision 4.0, Methods for the Determinationof Organic Compounds i
17、n Drinking Water52.3 OSHA Standard:29 CFR 1910 OSHA Safety and Health Standards, GeneralIndustry63. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standard:3.2.1 internal standarda pure analyte(s) added
18、 to a solu-tion in known amount(s) and used to measure the relativeresponses of other method analytes and surrogates that arecomponents of the same solution.3.2.1.1 DiscussionThe internal standard must be an ana-lyte that is not a sample component.3.2.2 surrogate analytea pure analyte(s), which is e
19、x-tremely unlikely to be found in any sample, and which is addedto a sample aliquot in known amount(s) before extraction andis measured with the same procedures used to measure othersample components.3.2.2.1 DiscussionThe purpose of a surrogate analyte is tomonitor method performance with each sampl
20、e.4. Summary of Test Method4.1 The compounds listed in 1.1, in water samples, areconverted into sodium salts by adjusting the pH to 12 withsodium hydroxide solution (240 g/L) and shaking for 1 h.Extraneous neutral material is removed by extraction withmethylene chloride. The sample is acidified, the
21、 acids areextracted with ethyl ether and converted to methyl esters usingdiazomethane. After the excess reagent is removed, the methylesters are determined by capillary column GC using an electroncapture (EC) detector. Other detection systems, such as micro-coulometric and electrolytic conductivity,
22、 are not as sensitiveas EC for measurement of chlorinated acid esters but are morespecific and less subject to interferences. A mass spectrometermay also be used as a detector.4.2 This test method provides a magnesium silicate7cleanup procedure to aid in the elimination of interferences thatmay be p
23、resent.5. Significance and Use5.1 Chlorinated phenoxyacid herbicides, and other organicacids are used extensively for weed control. Esters and salts of2,4-D and silvex have been used as aquatic herbicides in lakes,streams, and irrigation canals. Phenoxy acid herbicides can betoxic even at low concen
24、trations. For example, the 96 h, TLmfor silvex is 2.4 mg/L for bluegills (1)8. These reasons makeapparent the need for a standard test method for such com-pounds in water.6. Interferences6.1 Method interferences may be caused by contaminants insolvents, reagents, glassware and other sample processin
25、gapparatus that lead to discrete artifacts or elevated baselines ingas chromatograms. All reagents and apparatus must be rou-tinely demonstrated to be free from interferences under theconditions of the analysis by running laboratory reagent blanksas described in 19.2.6.1.1 Glassware must be scrupulo
26、usly cleaned (2). Clean allglassware as soon as possible after use by thoroughly rinsingwith the last solvent used in it. Follow by washing with hotwater and detergent and thoroughly rinsing with dilute acid,tap, and reagent water. Drain dry, and heat in an oven or mufflefurnace at 400C for 1 h. Do
27、not heat volumetric ware.Thorough rinsing with acetone may be substituted for theheating. After drying and cooling, seal and store glassware ina clean environment to prevent any accumulation of dust orother contaminants. Store inverted or capped with aluminumfoil. Thermally stable materials such as
28、PCBs may not beeliminated by this treatment.6.1.2 The use of high purity reagents and solvents helps tominimize interference problems. Purification of solvents bydistillation in all-glass systems may be required. (WarningWhen a solvent is purified, stabilizers added by the manufac-turer are removed,
29、 thus potentially making the solvent hazard-ous. Also, when a solvent is purified, preservatives added bythe manufacturer are removed, thus potentially reducing theshelf-life.)6.2 The acid forms of the analytes are strong organic acidsthat react readily with alkaline substances and can be lostduring
30、 sample preparation. Glassware and glass wool must beacid-rinsed with hydrochloric acid (1 + 9) and the sodiumsulfate must be acidified with sulfuric acid prior to use to avoidanalyte loses due to adsorption.6.3 Organic acids and phenols, especially chlorinated com-pounds, cause the most direct inte
31、rference with the determina-tion.Alkaline hydrolysis and subsequent extraction of the basicsample removes many chlorinated hydrocarbons and phthalateesters that might otherwise interfere with the electron captureanalysis.6.4 Interferences by phthalate esters can pose a majorproblem in pesticide anal
32、ysis when using the ECD. Thesecompounds generally appear in the chromatogram as largepeaks. Common flexible plastics contain varying amounts ofphthalates, which are easily extracted or leached during labo-ratory operations. Cross contamination of clean glasswareroutinely occurs when plastics are han
33、dled during extractionsteps, especially when solvent-wetted surfaces are handled.Interferences from phthalates can best be minimized by avoid-ing the use of plastics in the laboratory. Exhaustive purificationof reagents and glassware may be required to eliminatebackground phthalate contamination (3)
34、.6.5 Interfering contamination may occur when a samplecontaining low concentrations of analytes is analyzed imme-diately following a sample containing relatively high concen-trations of analytes. Between-sample rinsing of the samplesyringe and associated equipment with methyl-t-butyl-ether(MTBE) can
35、 minimize sample cross contamination. After5EPA/600/4-88/039, 1989, available from Environmental Monitoring SystemsLaboratory, U.S. Environmental Protection Agency, Cincinnati, OH 45268.6Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE
36、, Washington, DC 20401.7Florisil, a trademark of, and available from, Floridin Co., 2 Gateway Center,Pittsburgh, PA 15222, or its equivalent, has been found satisfactory for this purpose.8The boldface numbers in parentheses refer to the list of references at the end ofthis test method.D5317 98 (2011
37、)2analysis of a sample containing high concentrations of ana-lytes, one or more injections of MTBE should be made toensure that accurate values are obtained for the next sample.6.6 Matrix interferences may be caused by contaminantsthat are coextracted from the sample. Also, note that allanalytes lis
38、ted in Table 1 are not resolved from each other onany one column, that is, one analyte of interest may be aninterferent for another analyte of interest. The extent of matrixinterferences will vary considerably from source to source,depending upon the water sampled. The procedures in Section16 can be
39、 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 becontained in the same solvent. The solvent for workingstandards must be the same as the final solvent used in samplepreparation
40、. If this is not the case, chromatographic compara-bility of standards to sample may be affected.7. Apparatus and Equipment7.1 Sample BottleBorosilicate amber, 1-L volume withgraduations, fitted with screw caps lined with TFE-fluorocarbon. Protect samples from light. The container mustbe washed and
41、dried as described in 6.1.1 before use tominimize contamination. Cap liners are cut to fit from sheetsand extracted with methanol overnight prior to use.7.2 Glassware.7.2.1 Separatory funnel, 2000-mL, with TFE-fluorocarbonstopcocks, ground glass or TFE-fluorocarbon stoppers.7.2.2 Tumbler bottle, 1.7
42、-L with TFE-fluorocarbon linedscrew cap. Cap liners are cut to fit from sheets and extractedwith methanol overnight prior to use.7.2.3 Concentrator tube, Kuderna-Danish (K-D), 10 or25-mL, graduated. Calibration must be checked at the volumesemployed in the procedure. Ground-glass stoppers are used t
43、oprevent evaporation of extracts.7.2.4 Evaporative flask, K-D, 500-mL. Attach to concentra-tor tube with springs.7.2.5 Snyder column, K-D, three ball macro.7.2.6 Snyder column, K-D, two ball micro.7.2.7 Flask, round bottom, 500-mL with 24/40 ground glassjoint.7.2.8 Vials, glass, 5 to 10-mL capacity
44、with TFE-fluorocarbon lined screw cap.7.3 Boiling Stone, TFE-fluorocarbon.7.4 Water Bath, heated, capable of temperature control(62C). The bath should be used in a hood.7.5 Diazomethane GeneratorAssemble from two 20- by155-mm test tubes, two neoprene rubber stoppers, and a sourceof nitrogen as shown
45、 in Fig. 1.7.6 Glass Wool, acid washed and heated at 450C.7.7 Gas ChromatographAnalytical system complete withtemperature programmable GC suitable for use with capillarycolumns and all required accessories including syringes, ana-lytical columns, gases, detector, and stripchart recorder. A datasyste
46、m is recommended for measuring peak areas. Table 1 listsretention times observed for test method analytes using thecolumns and analytical conditions described below.7.7.1 Column 1 (Primary Column), 30-m long by 0.25-mminside diameter (I.D.) DB-5 bonded fused silica column,0.25-m film thickness. Esta
47、blish helium carrier gas flow at 30cm/s linear velocity and program oven temperature from 60Cto 300C at 4C/m. Data presented in this test method wereobtained using this column (Table 1). The injection volume is2 L splitless mode with 45 s delay. The injector temperatureis 250C and the detector is 32
48、0C. Alternative columns maybe used in accordance with the provisions described in 19.3.7.7.2 Column 2 (Confirmation Column), 30-m long by0.25-mm I.D. DB-1701 bonded fused silica column, 0.25-mfilm thickness. Establish helium carrier gas flow at 30 cm/slinear velocity and program oven temperature fro
49、m 60C to300C at 4C/m.FIG. 1 Gaseous Diazomethane GeneratorTABLE 1 Retention Times and Estimated Method DetectionLimits for Method AnalytesAnalyte CAS No.Retention TimeA(min)EDLBPrimary Confirmation3,5-Dichlorobenzoicacid51-36-5 18.6 17.7 0.061DCAA (surrogate) 19719-28-9 22.0 14.9 .Dicamba 1918-00-9 22.1 22.6 0.081Dichlorprop 120-36-5 25.0 25.6 0.262,4-D 94-75-7 25.5 27.0 0.2DBOB (int. std.) 10386-84-2 27.5 27.6 .Pentachlorophenol 87-86-5 28.3 27.0 0.0762,4,5-TP 93-72-1 29.7 29.5 0.0755-Hydroxydicamba 7600-50-2 30.0 30.7 0.042,4,5-T 93-76-5 30.5 30.9 0.082,4
