1、Designation: D 5316 98 (Reapproved 2004)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 D 5316; the number immediately following the designation indicates the year oforigin
2、al adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of 1,2-dibromoethane (
3、commonly 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 an
4、d groundwaters. 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 respon
5、sibility to ensurethe validity of this test method for waters of untested matrices.1.3 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-priate safety and health practices and
6、determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see Sections 6 and 9.2. Referenced Documents2.1 ASTM Standards:2D 1066 Practice for Sampling SteamD 1129 Terminology Relating to WaterD 1192 Specification for Equipment for Sampling Waterand Steam in
7、Closed Conduits3D 1193 Specification for Reagent WaterD 3370 Practices for Sampling Water from Closed ConduitsD 3856 Guide for Good Laboratory Practices in Laborato-ries Engaged in Sampling and Analysis of WaterD 4210 Practice for Interlaboratory Quality Control Proce-dures and a Discussion on Repor
8、ting Low-Level Data3D 5789 Practice for Writing Quality Control Specificationsfor Standard Test Methods for Organic Constituents32.2 U.S. Environmental Protection Agency Standards:Winfield, T. W., “U.S. EPA Method 504, Revision 2.0,”Methods for the Determination of Organic Compounds inDrinking Water
9、, 198943. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D 1129.4. Summary of Test Method4.1 This test method consists of microextraction of thesample followed by gas chromatographic analysis of theextract.4.2 An aliquot of the sample is extracted wi
10、th 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-tracted and analyzed in an identical manner as the samples inorder to compensate for possible extraction lo
11、sses.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 component concentrations are sufficientlyhigh, Gas Chromatography/Mass Spectrometric (GC/MS)methods may be u
12、sed 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 thismethod, see 1.2.5.2 EDB and DBCP have been widely used as soil fumi-gants. EDB is also used as a lead sca
13、venger in leaded gasolines.These compounds are very water soluble and are often found ingroundwater and drinking water. Since they are highly toxicand are suspected carcinogens, there is concern about thepotential health impact of even extremely low concentrationsin potable water.1This test method i
14、s under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06 on Methods forAnalysis forOrganic Substances in Water.Current edition approved June 1, 2004. Published June 2004. Originallyapproved in 1992. Last previous edition approved in 1998 as D 531
15、698.2For 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 ASTM website.3Withdrawn.4Available from U.S. Environmental Protection
16、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.6. Interferences6.1 Impurities contained in the extracting solvent usuallyaccount for the majority of the analytical problems.
17、 Solventblanks should be analyzed on each new bottle of solvent beforeuse. Indirect 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 gene
18、rally can beremoved by distillation or column chromatography.NOTE 1When a solvent 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 re
19、moved, thus potentially making theshelf-life short. However, it is generally more 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 k
20、nown to be free oforganochlorine solvents.6.2 This liquid-liquid extraction technique 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
21、 thatEDB at low concentrations may be masked by very high levelsof dibromochloromethane (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 equi
22、pped with a linearized elec-tron capture detector and a capillary column splitless 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 providesseparation
23、s for EDB and DBCP without interferences fromtrihalomethanes. Column A should be 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
24、for EDB and DBCP on these columnsare presented in Table 1.7.1.3 Column AA 0.32-mm 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 in
25、crease to 190C at 8C/min, and hold at190C for 25 min or until all expected compounds 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 shou
26、ld beabout 25 cm/s at 100C. The column temperature is pro-grammed to hold at 40C 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 dimeth
27、yldiphenyl polysiloxane, bonded phase with 2.0 m film.8Thehydrogen carrier gas flow 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: 35
28、0C.97.2 Sample ContainersForty-mL screw cap vials, eachequipped with a size 24 cap, with a flat, disc-like PTFE-facedpolyethylene film/foam extrusion. Individual vials shown tocontain at least 40.0 mL can be calibrated at the 35.0 mL markso that volumetric, rather than gravimetric, measurements of5A
29、n alternative column has been recommended by the Restek Corporation andis described 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 regulationsrega
30、rding safe handling of chemicals used in this test method.Additional references 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 t
31、hese com-pounds should be handled in a hood or glovebox. A NIOSH/MESA approved 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
32、making the solventhazardous.10. Sample Collection, Preservation, and Storage10.1 Sample Collection:10.1.1 Collect the sample in accordance with PracticeD 1066, Specification D 1192, and Practices D 3370, as appli-cable.10.1.2 Collect all samples in 40-mL bottles into which 3 mgof sodium thiosulfate
33、crystals have been added to the emptybottles just prior to shipping to the sampling 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
34、 to flush until the water temperature hasstabilized (usually about 10 min). Adjust 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
35、:10.2.1 Chill the samples to 4C on the day of collection andmaintain at that temperature until analysis. Field samples thatwill 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“R
36、eagent 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, Dorset, UK, and the“ United States Pharmacopeia
37、.”D 5316 98 (2004)310.2.2 The addition of sodium thiosulfate as a dechlorinat-ing 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 add
38、ed to avoid thepossibility of reactions that may occur between residualchlorine 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
39、 shouldbe acidified to avoid the possibility of microbial degradationthat may periodically 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 solve
40、nt vapors.10.3.2 Analyze all samples within 28 days of collection.11. Preparation 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 ma
41、nufacturer.11.2 Instrument PerformanceCheck the performance ofthe entire analytical 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
42、precision between replicate analyses. Aproperly operating system will exhibit an 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 aconcentr
43、ation near to the reporting limit for each compound;the other two should be at 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 les
44、s than 20 L ofan alcoholic standard is added to the reagent water, poorprecision 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 seve
45、ral times.Aqueous standards should be prepared fresh and extractedimmediately after 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
46、 in the standard. Use the results toprepare a calibration curve for each compound.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 c
47、alibration factor may be used in place of acalibration curve.12.1.4 Single point 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 re
48、sponseclose to that of the unknowns, that is, no more than 20 %deviation between 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 blank
49、s, contained in40-mL bottles, remove container cap. Discard a 5-mL volumeusing 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
