1、Designation: D5316 98 (Reapproved 2011)Standard Test Method for1,2-Dibromoethane and 1,2-Dibromo-3-Chloropropane inWater by Microextraction and Gas Chromatography1This standard is issued under the fixed designation D5316; the number immediately following the designation indicates the year oforiginal
2、 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 the determination of 1,2-dibromoethane (com
3、monly referred to as ethylene dibromideor EDB) and 1,2-dibromo-3-chloropropane (commonly re-ferred to as DBCP) in water at a minimum detection level of0.010 g/L by liquid-liquid extraction combined with gas-liquid chromatography. This test method is applicable to theanalysis of drinking waters and g
4、roundwaters. It is not recom-mended for wastewaters, due to the potential for interferencesfrom high concentrations of other extractable organics. Similarinformation can be found in EPA Method 504.1.2 This test method was used successfully with reagentwater and groundwater. It is the users responsib
5、ility to ensurethe validity of this test method for waters of untested matrices.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with
6、 its 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. For specific hazardstatements, see Sections 6 and 9.2. Referenced Documents2.1 ASTM Standards:2D1066 Practice
7、for Sampling SteamD1129 Terminology Relating to WaterD1192 Guide for Equipment for Sampling Water and Steamin Closed Conduits3D1193 Specification for Reagent WaterD3370 Practices for Sampling Water from Closed ConduitsD3856 Guide for Good Laboratory Practices in Laborato-ries Engaged in Sampling and
8、 Analysis of WaterD4210 Practice for Intralaboratory Quality Control Proce-dures and a Discussion on Reporting Low-Level Data3D5789 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Organic Constituents32.2 U.S. Environmental Protection Agency Standards:Winfield, T. W.
9、, “U.S. EPA Method 504, Revision 2.0,”Methods for the Determination of Organic Compounds inDrinking Water, 198943. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D1129.4. Summary of Test Method4.1 This test method consists of microextraction of thesa
10、mple followed by gas chromatographic analysis of theextract.4.2 An aliquot of the sample is extracted with hexane. TwoL of the extract are then injected into a gas chromatographequipped with a linearized electron capture detector for sepa-ration and analysis. Aqueous calibration standards are ex-tra
11、cted and analyzed in an identical manner as the samples inorder to compensate for possible extraction losses.4.3 The extraction and analysis time is 30 to 50 min persample, depending upon the analytical conditions chosen.4.4 Confirmatory evidence can be obtained using a dissimi-lar column. When comp
12、onent concentrations are sufficientlyhigh, Gas Chromatography/Mass Spectrometric (GC/MS)methods may be used for confirmation analysis. (See EPAMethod 524.2.)5. Significance and Use5.1 This test method is useful for the analysis of drinkingwater and groundwaters. Other waters may be analyzed by thism
13、ethod, see 1.2.5.2 EDB and DBCP have been widely used as soil fumi-gants. EDB is also used as a lead scavenger in leaded gasolines.These compounds are very water soluble and are often found in1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility o
14、f Subcommittee 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 2004 as D5316 98 (2004). DOI:10.1520/D5316-98R11.2For referenced ASTM standards, visit the ASTM website
15、, 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 ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Available from U.S.
16、 Environmental Protection Agency, 26 W. Martin LutherKing Ave., Cincinnati, OH 45268.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.groundwater and drinking water. Since they are highly toxicand are suspected carcinogens, there is c
17、oncern about thepotential health impact of even extremely low concentrationsin potable water.6. Interferences6.1 Impurities contained in the extracting solvent usuallyaccount for the majority of the analytical problems. Solventblanks should be analyzed on each new bottle of solvent beforeuse. Indire
18、ct daily checks on the extracting solvent are obtainedby monitoring the water blanks. Whenever an interference isnoted in the water blank, the analyst should reanalyze theextracting solvent. Low-level interferences generally can beremoved by distillation or column chromatography.NOTE 1When a solvent
19、 is purified, stabilizers put into the solvent bythe manufacturer are removed, thus potentially making the solventhazardous. Also, when a solvent is purified, preservatives put into thesolvent by the manufacturer are removed, thus potentially making theshelf-life short. However, it is generally more
20、 economical to obtain a newsource of solvent. Interference-free solvent is defined as a solventcontaining less than 0.1 g/L individual analyte interference. Protectinterference-free solvents by storing them in an area known to be free oforganochlorine solvents.6.2 This liquid-liquid extraction techn
21、ique efficiently ex-tracts a wide boiling range of nonpolar organic compoundsand, in addition, extracts polar organic components of thesample with varying efficiencies.6.3 Current column technology suffers from the fact thatEDB at low concentrations may be masked by very high levelsof dibromochlorom
22、ethane (DBCM), a common disinfectionby-product of chlorinated drinking waters.7. Apparatus and Equipment7.1 Gas Chromatography (GC) System:7.1.1 The GC system must be capable of temperatureprogramming and should be equipped with a linearized elec-tron capture detector and a capillary column splitles
23、s injector at200C. Separate heated zones for the injector and detectorcomponents are recommended.7.1.2 Two gas chromatography columns are recommended.Column A (7.1.3) is a highly efficient column that providesseparations for EDB and DBCP without interferences fromtrihalomethanes. Column A should be
24、used as the primaryanalytical column unless routinely occurring analytes are notadequately resolved. Column B (7.1.4) is recommended for useas a confirmatory column when GC/MS confirmation is notviable.5Retention times for EDB and DBCP on these columnsare presented in Table 1.7.1.3 Column AA 0.32-mm
25、 ID by 30-m long fused silicacapillary with dimethyl silicone mixed phase.6The linearvelocity of the helium carrier gas should be about 25 cm/s at100C. The column temperature is programmed to hold at40C for 4 min, to increase to 190C at 8C/min, and hold at190C for 25 min or until all expected compou
26、nds have eluted.(See Fig. 1 for a sample chromatogram.)7.1.4 Column B (alternative column)A 0.32-mm ID by30-m long fused silica capillary with methyl polysiloxanephase.7The linear velocity of the helium carrier gas should beabout 25 cm/s at 100C. The column temperature is pro-grammed to hold at 40C
27、for 4 min, to increase to 270C at10C/min, and hold at 270C for 10 min or until all expectedcompounds have eluted.7.1.5 Column C5(alternative column, wide bore)A 0.53-mm ID by 30-m long fused silica capillary with dimethyldiphenyl polysiloxane, bonded phase with 2.0 m film.8Thehydrogen carrier gas fl
28、ow is about 80 cm/s linear velocity,measured at 50C. The oven temperature is programmed tohold at 200C until all expected compounds have eluted.7.1.6 Other Heated ZonesInjector temperature: 250C.Detector temperature: 350C.95An alternative column has been recommended by the Restek Corporation andis d
29、escribed in 7.1.5 as Column C.6J each chemicalshould be treated as a potential health hazard, and exposure tothese chemicals should be minimized. Each laboratory isresponsible for maintaining awareness of OSHA regulationsregarding safe handling of chemicals used in this test method.Additional refere
30、nces to laboratory safety need to be madeavailable to the analyst.9.2 EDB and DBCP have been tentatively classified asknown or suspected human or mammalian carcinogens. Purestandard materials and stock standard solutions of these com-pounds should be handled in a hood or glovebox. A NIOSH/MESA appro
31、ved toxic gas respirator should be worn when theanalyst handles high concentrations of these toxic compounds.NOTE 2When a solvent is purified, stabilizers put into the solvent bythe manufacturer are removed, thus potentially making the solventhazardous.10. Sample Collection, Preservation, and Storag
32、e10.1 Sample Collection:10.1.1 Collect the sample in accordance with PracticeD1066, Specification D1192, and Practices D3370, as appli-cable.10.1.2 Collect all samples in 40-mL bottles into which 3 mgof sodium thiosulfate crystals have been added to the emptybottles just prior to shipping to the sam
33、pling site. Alternately,add 75 Lof freshly-prepared sodium thiosulfate solution (0.04mg/L) added to empty 40-mL bottles just prior to samplecollection.10.1.3 When sampling from a water tap, open the tap andallow the system to flush until the water temperature hasstabilized (usually about 10 min). Ad
34、just the flow to about 500mL/min and collect samples from the flowing stream.10.1.4 When sampling from a well, fill a wide mouthedbottle or beaker with sample and carefully fill 40-mL samplebottles.10.2 Sample Preservation:10.2.1 Chill the samples to 4C on the day of collection andmaintain at that t
35、emperature until analysis. Field samples that10“Reagent Chemicals, American Chemical Society Specifications,” AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see “Standards for Laboratory Chemi-cals,” BDH Limited, Poole
36、, Dorset, UK, and the“ United States Pharmacopeia.”D5316 98 (2011)3will not be received at the laboratory on the day of collectionmust be packaged for shipment with sufficient ice to ensure thatthey will be #4C on arrival at the laboratory.10.2.2 The addition of sodium thiosulfate as a dechlorinat-i
37、ng agent or acidification, or both, to pH 2 with HCl (1 + 1),common preservative procedures for purgeable compounds,has been shown to have no effect on EDB or DBCP (see Table2). Nonetheless, sodium thiosulfate must be added to avoid thepossibility of reactions that may occur between residualchlorine
38、 and indeterminate contaminants present in somesolvents, yielding compounds which may subsequently inter-fere with the analysis. The presence of sodium thiosulfate willarrest the formation of DBCM (see 6.3). Also, samples shouldbe acidified to avoid the possibility of microbial degradationthat may p
39、eriodically affect these analytes contained in othergroundwater matrices.10.3 Sample Storage:10.3.1 Store samples and field reagent blanks together at4C until analysis. The sample storage area must be free oforganic solvent vapors.10.3.2 Analyze all samples within 28 days of collection.11. Preparati
40、on of Apparatus11.1 Set up the gas chromatograph in accordance with themanufacturers instructions. Install the capillary column(s) andtest for leaks using techniques recommended by the instru-ments or capillary columns manufacturer.11.2 Instrument PerformanceCheck the performance ofthe entire analyt
41、ical system daily using data gathered fromanalyses of water blanks and standards.11.2.1 Correct significant peak tailing in excess of thatshown for the target compounds in the method chromatogram(Fig. 1).11.2.2 Check the precision between replicate analyses. Aproperly operating system will exhibit a
42、n average relativestandard deviation of less than 10 %.12. Calibration and Standardization12.1 Calibration:12.1.1 Use at least three calibration standards; five arerecommended. One should contain EDB and DBCP at aconcentration near to the reporting limit for each compound;the other two should be at
43、concentrations that bracket the rangeexpected in samples.12.1.2 To prepare a calibration standard (CAL), add anappropriate volume of a primary dilution standard solution toan aliquot of water in a volumetric flask. If less than 20 L ofan alcoholic standard is added to the reagent water, poorprecisio
44、n may result. Use a 25-L microsyringe and rapidlyinject the alcoholic standard into the expanded area of the filledvolumetric flask. Remove the needle as quickly as possibleafter injection. Mix by inverting the flask several times.Aqueous standards should be prepared fresh and extractedimmediately a
45、fter preparation unless sealed and stored withoutheadspace as described in 8.11.12.1.3 Each day, analyze each calibration standard accord-ing to Section 12 and tabulate peak height or area responseversus the concentration in the standard. Use the results toprepare a calibration curve for each compou
46、nd.Alternatively, ifthe ratio of concentration to response (calibration factor) is aconstant over the working range ( 20 % relative standarddeviation), linearity through the origin may be assumed and theaverage ratio or calibration factor may be used in place of acalibration curve.12.1.4 Single poin
47、t calibration is a viable alternative to acalibration curve. Prepare single point standards from thesecondary dilution standard solutions. Prepare the single pointcalibration standard at a concentration that produces a responseclose to that of the unknowns, that is, no more than 20 %deviation betwee
48、n response of the standard and response of thesample.13. Procedure13.1 Sample Preparation:13.1.1 Remove samples and standards from storage andallow them to reach room temperature.13.1.2 For samples and field reagent blanks, contained in40-mL bottles, remove container cap. Discard a 5-mL volumeusing
49、a 5-mL transfer pipet or 10-mL graduated cylinder.Replace the container cap and weigh the container withcontents to the nearest 0.1 g and record this weight forsubsequent sample volume determination (13.3).13.1.3 For calibration standards, laboratory fortified blanks,and laboratory reagent blanks, measure a 35-mL volume usinga 50-mL graduated cylinder and transfer it to a 40-mL samplecontainer.13.2 Microextraction and Analysis:13.2.1 Remove the container cap and add 6 g NaCl (see 8.8)to the sample.13.2.2 Recap the sample container and dissolve the
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