1、Designation: D3973 85 (Reapproved 2017)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 ofhalomethanes, haloethanes, and some related extractable or-ganohalides amenable to gas chromatographic measurement.The applicable concentration range for trihalomethanes is from1 to 200 g/L. Detection limits depe
4、nd on the compound,matrix, and on the characteristics of the gas chromatographicsystem.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 identit
5、ies 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 level
6、s 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 its
7、use. It is theresponsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Specific precautionary statements are given in Section 8.1.7 This international standard was develop
8、ed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Docume
9、nts2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD3871 Test Method for Purgeable Organic Compounds inWater Using Headspace SamplingE355 Practice for Gas Chromatography Terms and Relation-ships3. Terminology3.1 Definitions:3.1.1 For definitions of terms u
10、sed in this standard, refer toTerminology 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.3,4,5A 5-mL aque-ous sample is extracted once with
11、1 mL of solvent. A 3-Laliquot of the extract 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 a
12、na-lyzed in an identical manner.4.3 The concentration of each component is calculated andreported in micrograms per litre.1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods forAnalysis forOrganic Substances in
13、Water.Current edition approved Dec. 15, 2017. Published December 2017. Originallyapproved in 1980. Last previous edition approved in 2011 as D3973 85 (2011).DOI: 10.1520/D3973-85R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.o
14、rg. 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., “Liquid Extracti
15、on for Rapid Determination ofHalomethanes in Water,” Journal AWWA, Vol 69, 1977, p. 62.5“The Analysis of Trihalomethanes in Drinking Water by Liquid/LiquidExtraction,” U.S. Environmental Protection Agency, EMSL, Cincinnati, OH, Sept.9, 1977.Copyright ASTM International, 100 Barr Harbor Drive, PO Box
16、 C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by th
17、e World Trade Organization Technical Barriers to Trade (TBT) Committee.15. 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. This test
18、 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 solvent can be
19、 a source ofinterference. Solvent blanks should be analyzed daily andbefore a new bottle of solvent is used for the first time.Whenever interfering compounds are traced to the solvent, anew source of solvent should be obtained. Alternatively,impurities may be removed by distillation, column chromato
20、g-raphy3or purging with high-purity nitrogen or helium. Thisprocedure 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 Containe
21、rs, 40-mL screw cap vials sealed withPTFE-faced silicone septa.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 sui
22、table for this analysis. See Fig. 1 for chromatograms.If other 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
23、100/120 mesh support7coated witha methyl silicone liquid phase8and 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 polarliquid phase such as polyethylene glycol9and operated at 50Cwith 60 mL/min
24、 carrier flow.8. Reagents8.1 Purity of ReagentsReagent grade chemicals shall beused in 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 ChemicalSociety,10where such specifications are a
25、vailable. Other gradesmay be used, provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe accuracy of the determination.8.2 Purity of WaterUnless otherwise indicated, Specifica-tion D1193 reagent water, Type II, will be used in this tes
26、tmethod. In addition the water is made organic-free by passingit through a filter bed 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, suitabl
27、e for laboratory glassware.8.6 Isooctane, pesticide grade.138.7 Methyl Alcohol, pesticide 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.8.1
28、0 Stock SolutionsPrepare a stock solution (2 to 10mg/mL) for each standard as follows: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 han
29、dles high concentra-tions of such materials.613075 vials and 12722 septa, available from Pierce Chemical Co., P.O. Box117, Rockford, IL 61105, have been found suitable; other sources that are equivalentmay be substituted.7Gas-Chrom Q, available from Applied Science Laboratory, Inc., P.O. Box 440,Sta
30、te 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,Marietta, OH 45750, has been found suitable; other sources that are equivalent maybe substituted.9SP-1000, available from Supelco,
31、Inc., Supelco Park, Bellafonte, PA16823, hasbeen found suitable; other sources that are equivalent may be substituted.10Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical
32、 Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.11Super Q water system, available from Millipore Corp. Ashby Rd., Bedford,MA 01730, has been foun
33、d suitable; other sources that are equivalent may besubstituted.12Filtrasorb 200, available from Calgon Corp., Box 1346, Pittsburgh, PA 15230,has been found suitable; other sources that are equivalent may be substituted.13Pesticide grade, available from Burdick other sources that are equivalent may
34、be substituted.14Pesticide grade, available from Burdick other sources which are equivalent may be substituted.15Bromodichloromethane, available fromAldrich Chemical Co., Inc., 940 W. St.Paul Ave., Milwaukee, WI 53233, has been found suitable; other sources that areequivalent may be substituted.16Ch
35、lorodibromomethane, available from Chemical Service Inc., 1887 LincolnAve., West Chester, PA, has been found suitable; other sources that are equivalentmay be substituted.D3973 85 (2017)28.10.2 Fill a 10.0-mL ground-glass-stoppered volumetricflask with approximately 9.8 mL of methyl alcohol.8.10.3 A
36、llow 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 reference standards (8.9) to the flask, thenreweigh. Be sure that the drops fall
37、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 from the net gain in weight.8.10.8 Store the solutions at 4C. Warm to roo
38、m 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 Preparation:9.1.1 Wash all sample vials and septa in detergent water.Rinse with tap
39、 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 of time (1h) because the silicone layer slowly degrades at 105C.9.1.3 When
40、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 sample collection, add thechemical dechlorinating agent (8.4) to the sample
41、 and blanks.Add chemical preservative (2.5 to 3 mg/40 mL) in crystallineFIG. 1 Chromatograms of StandardsD3973 85 (2017)3form 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 collected in asampling v
42、ial, 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 does not permit replicatea
43、nalyses 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. Fill thevial to overflowi
44、ng 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 present, open thebottle, add a
45、 few additional drops of water and reseal. Maintainthis seal until analysis.9.3.1.1 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
46、flush. When the temperature of the waterhas stabilized, 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
47、 the 1-L container.9.3.4 Prepare sample blanks, including 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 bl
48、ank and the samples from agiven site together. Retain 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 sec
49、ondary dilution mixture containing approximately5000 times the expected water concentration of eachcomponent, 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 calibration 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
