1、Designation: D3973 85 (Reapproved 2011)Standard Test Method forLow-Molecular Weight Halogenated Hydrocarbons in Water1This standard is issued under the fixed designation D3973; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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 the analysis of drinking water.It is also applicable to many environmental and waste wat
3、erswhen adequate validation is included.1.2 This test method covers the determination of halometh-anes, haloethanes, and some related extractable organohalidesamenable to gas chromatographic measurement. The appli-cable concentration range for trihalomethanes is from 1 to 200g/L. Detection limits de
4、pend on the compound, matrix, and onthe characteristics of the gas chromatographic system.1.3 For compounds not specifically included in the precisionand bias section the analyst should validate the test method bycollecting precision and bias data on actual samples.1.4 Confirmation of component iden
5、tities is obtained byobserving retention times using gas chromatographic columnsof different polarities. When concentrations are sufficientlyhigh (50 g/L) confirmation with halogen specific detectorsor gas chromatography/mass spectrometry (GC/MS) may beused. Confirmation of purgeable compounds at le
6、vels down to1 g/L can be obtained using Test Method D3871 with GC/MSdetection.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with i
7、ts use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2D1129 Termi
8、nology Relating to WaterD1193 Specification for Reagent WaterD3871 Test Method for Purgeable Organic Compounds inWater Using Headspace SamplingE355 Practice for Gas Chromatography Terms and Rela-tionships3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminol
9、ogy D1129 and Practice E355.4. Summary of Test Method4.1 This test method employs liquid/liquid extraction toisolate compounds of interest and provide a five-fold concen-tration enhancement prior to measurement.3,4 ,5A5-mLaqueoussample is extracted once with 1 mL of solvent. D3871-Laliquot of the ex
10、tract is analyzed in a gas chromatographequipped with an electron-capture detector.4.2 Extraction efficiencies with the 1:5 solvent/sample ratiofor trihalomethanes average above 90 %. To compensate forextraction losses, calibration standards are extracted and ana-lyzed in an identical manner.4.3 The
11、 concentration of each component is calculated andreported in micrograms per litre.5. Significance and Use5.1 The incidental conversion of organic material to triha-lomethanes and other volatile organohalides during chlorina-tion of water is a possible health hazard and is the object ofmuch research
12、. This test method can be used as a rapid, simplemeans for determining many volatile organohalides in raw andprocessed water.6. Interferences6.1 Volatile compounds that are extractable and responsiveto electron-capture detection may interfere with this testmethod.6.2 Impurities in the extracting sol
13、vent can be a source ofinterference. Solvent blanks should be analyzed daily andbefore a new bottle of solvent is used for the first time.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods forAnalysis forOrgani
14、c Substances in Water.Current edition approved May 1, 2011. Published June 2011. Originallyapproved in 1980. Last previous edition approved in 2003 as D3973 85 (2003).DOI: 10.1520/D3973-85R03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at ser
15、viceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Mieure, J. P., “A Rapid and Sensitive Method for Determining VolatileOrganohalides in Water,” Journal AWWA, Vol 69, 1977, p. 60.4Richard, J. J., and Junk, G. A., “Liqui
16、d Extraction for Rapid Determination ofHalomethanes in Water,” Journal AWWA , Vol 69, 1977, p. 62.5“The Analysis of Trihalomethanes in Drinking Water by Liquid/Liquid Extrac-tion,” U.S. Environmental ProtectionAgency, EMSL, Cincinnati, OH, Sept. 9, 1977.1Copyright ASTM International, 100 Barr Harbor
17、 Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Whenever interfering compounds are traced to the solvent, anew source of solvent should be obtained. Alternatively,impurities may be removed by distillation, column chromatog-raphy3or purging with high-purity nitrogen or helium. Th
18、isprocedure is quantitative as long as solvent interference con-tributes less than 10 % to the component concentration in thesample.7. Apparatus7.1 Extraction Vessel, 9-mL (2-dram) vial with aluminumfoil or PTFE-lined caps.7.2 Sample Containers, 40-mL screw cap vials sealed withPTFE-faced silicone s
19、epta.67.3 Micro Syringes, 10, 100-L.7.4 Pipets, 1.0 and 5.0-mL transfer.7.5 Glass-Stoppered Volumetric Flasks, 10 and 100-mL.7.6 Gas Chromatograph, with electron-capture detector.7.7 Columns, either of the following columns have beenfound suitable for this analysis. See Fig. 1 for chromatograms.If o
20、ther column conditions are used, it is up to the analyst todemonstrate the precision and bias statements are met bycollecting precision, bias, and recovery data.7.7.1 Nonpolar, 3-mm inside diameter by 2-m long boro-silicate glass packed with 100/120 mesh support7coated witha methyl silicone liquid p
21、hase8and operated at 60C with 45mL/min carrier flow.7.7.2 Polar, 3-mm inside diameter by 2-m long borosilicateglass packed with 100/120 mesh support7coated with a polar613075 vials and 12722 septa, available from Pierce Chemical Co., P.O. Box117, Rockford, IL 61105, have been found suitable; other s
22、ources that are equivalentmay be substituted.7Gas-Chrom Q, available from Applied Science Laboratory, Inc., P.O. Box 440,State College, PA 16801, has been found suitable; other sources that are equivalentmay be substituted.8OV-101, available from Ohio Valley Specialty Chemical, Inc., Route 6,Mariett
23、a, OH 45750, has been found suitable; other sources that are equivalent maybe substituted.FIG. 1 Chromatograms of StandardsD3973 85 (2011)2liquid phase such as polyethylene glycol9and operated at 50Cwith 60 mL/min carrier flow.8. Reagents8.1 Purity of ReagentsReagent grade chemicals shall beused in
24、all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Soci-ety,10where such specifications are available. Other gradesmay be used, provided it is first ascertained that the reagent
25、isof sufficiently high purity to permit its use without lesseningthe accuracy of the determination.8.2 Purity of Water Unless otherwise indicated, Specifi-cation D1193 reagent water, Type II, will be used in this testmethod. In addition the water is made organic-free by passingit through a filter be
26、d containing about 0.4 kg of activatedcarbon (8.3), or using a commercial water purification sys-tem.118.3 Activated Carbon.128.4 Dechlorinating AgentGranular sodium thiosulfate orascorbic acid.8.5 Detergent, suitable for laboratory glassware.8.6 Isooctane, pesticide grade.138.7 Methyl Alcohol, pest
27、icide grade.148.8 Sodium Chloride, granular.8.9 Reference Standards:8.9.1 Bromoform.8.9.2 Bromodichloromethane.158.9.3 Chlorodibromomethane.168.9.4 Chloroform.8.9.5 Tetrachloroethylene.8.9.6 1,1,1-Trichloroethane.8.10 Stock Solutions Prepare a stock solution (2 to 10mg/mL) for each standard as follo
28、ws:8.10.1 WarningBecause of the toxicity of trihalometh-anes it is necessary to prepare primary dilutions in a hood. It isfurther recommended that a NIOSH/MESA-approved toxic gasrespirator be used when the analyst handles high concentra-tions of such materials.8.10.2 Fill a 10.0-mL ground-glass-stop
29、pered volumetricflask with approximately 9.8 mL of methyl alcohol.8.10.3 Allow the flask to stand unstoppered about 10 min oruntil all alcohol wetted surfaces dry.8.10.4 Weigh the unstoppered flask to the nearest 0.1 mg.8.10.5 Using a 100-L syringe, immediately add 5 to 25drops of one of the referen
30、ce standards (8.9) to the flask, thenreweigh. Be sure that the drops fall directly into the alcoholwithout contacting the neck of the flask.8.10.6 Dilute to volume with the alcohol, stopper, then mixby inverting the flask several times.8.10.7 Calculate the concentration in micrograms per mil-lilitre
31、 from the net gain in weight.8.10.8 Store the solutions at 4C. Warm to room tempera-ture before use.NOTE 1Standard solutions prepared in methyl alcohol are stable up to4 weeks when stored under these conditions. They should be discardedafter that time has elapsed.9. Sampling9.1 Sample Vial Preparati
32、on:9.1.1 Wash all sample vials and septa in detergent water.Rinse with tap water and finally with water (8.2).9.1.2 Allow the vials and septa to air dry, then place in an105C oven for 1 h and allow to cool in an area known to befree of organics.NOTE 2Do not heat the PTFE septa for extended periods o
33、f time (1h) because the silicone layer slowly degrades at 105C.9.1.3 When cool, seal the vials using the septa that will beused for sealing the samples.9.2 Sample PreservationIf residual chlorine is present inthe sample and it is desirable to arrest the formation ofadditional trihalomethanes after s
34、ample collection, add thechemical dechlorinating agent (8.4) to the sample and blanks.Add chemical preservative (2.5 to 3 mg/40 mL) in crystallineform to the empty sample vials just prior to shipping to thesampling site. Also chill the samples to 4C during storage.9.3 Sample CollectionSamples may be
35、 collected in asampling vial, requiring transfer to an extraction vial as part ofthe analysis, or directly into the extraction vial already con-taining the extraction solvent. The direct procedure minimizessample handling and may be less prone to chemical alterationor headspace losses. However, it d
36、oes not permit replicateanalyses unless multiple samples are collected. The procedurerequiring laboratory transfer has been validated by interlabo-ratory testing and is described as follows:9.3.1 Fill the sample vial in such a manner that no airbubbles pass through the sample as the vial is filled.
37、Fill thevial to overflowing and place on a level surface. Position thePTFE side of a septum on the convex meniscus and seal thevial by screwing the cap on tightly. Invert the vial and lightlytap the cap on a solid surface. The absence of entrained airindicates a successful seal. If bubbles are prese
38、nt, open thebottle, add a few additional drops of water and reseal. Maintainthis seal until analysis.9SP-1000, available from Supelco, Inc., Supelco Park, Bellafonte, PA16823, hasbeen found suitable; other sources that are equivalent may be substituted.10Reagent Chemicals, American Chemical Society
39、Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical
40、 Convention, Inc. (USPC), Rockville,MD.11Super Q water system, available from Millipore Corp. Ashby Rd., Bedford,MA 01730, has been found suitable; other sources that are equivalent may besubstituted.12Filtrasorb 200, available from Calgon Corp., Box 1346, Pittsburgh, PA 15230,has been found suitabl
41、e; other sources that are equivalent may be substituted.13Pesticide grade, available from Burdick other sources that are equivalent may be substituted.14Pesticide grade, available from Burdick other sources which are equivalent may be substituted.15Bromodichloromethane, available fromAldrich Chemica
42、l Co., Inc., 940 W. St.Paul Ave., Milwaukee, WI 53233, has been found suitable; other sources that areequivalent may be substituted.16Chlorodibromomethane, available from Chemical Service Inc., 1887 LincolnAve., West Chester, PA, has been found suitable; other sources that are equivalentmay be subst
43、ituted.D3973 85 (2011)39.3.1.1 If preservative (9.2) has been added to the samplevials, fill with the sample just to overflowing, seal the vial, andshake vigorously for 1 min.9.3.2 Sampling from a Water TapTurn on the water andallow the system to flush. When the temperature of the waterhas stabilize
44、d, adjust the flow to about 500 mL/min and collectduplicate samples from the flowing stream.9.3.3 Sampling from an Open Body of WaterFill a 1-Lwide-mouth container with sample from a representative area.Immediately fill duplicate sample vials from the 1-L container.9.3.4 Prepare sample blanks, inclu
45、ding the preservative, induplicate at the laboratory by filling and sealing the samplevials with water just prior to shipping to the sampling site. Shipone of the blanks to and from the sampling site along with thesample vials. Store this field blank and the samples from agiven site together. Retain
46、 the second blank as a laboratoryblank.9.3.5 Analyze the samples as soon as possible. Store thesamples at 4C for a period not to exceed 15 days.10. Calibration and Standardization10.1 Prepare, from the stock solutions (8.10), a multicom-ponent secondary dilution mixture containing approximately5000
47、times the expected water concentration of each compo-nent, using methyl alcohol as the solvent. If the expectedconcentration range is unknown, perform a preliminary range-finding measurement, using an aqueous calibration standard(10.2) containing approximately 100 g/L.10.2 Prepare an aqueous calibra
48、tion standard by injecting 20L of the secondary dilution mixture (10.1) into 100 mL waterin a volumetric flask.NOTE 3Aqueous calibration standards are not stable and should bediscarded after1h(8hifstored with zero headspace).10.3 Each day, extract and analyze the aqueous calibrationstandard under co
49、nditions identical to the sample procedure.13Record the area for each component for calculating results(12.1).10.4 The analyst must be aware of the linear response rangeof the electron-capture detector. Using aqueous calibrationstandards covering a broad concentration range, establish alinear range of the test method. Recheck monthly for eachcompound and the concentration range of interest. Wheneverresponses outside the linear range of the test method areobtained, dilute and reanalyze the sample.11. Procedure11.1 Weigh 1.50 g of sodium chloride into a c
