1、Designation: D5790 95 (Reapproved 2012)Standard Test Method forMeasurement of Purgeable Organic Compounds in Water byCapillary Column Gas Chromatography/Mass Spectrometry1This standard is issued under the fixed designation D5790; the number immediately following the designation indicates the year of
2、original 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 identification and simulta-neou
3、s measurement of purgeable volatile organic compounds.It has been validated for treated drinking water, wastewater,and ground water. This test method is not limited to theseparticular aqueous matrices; however, the applicability of thistest method to other aqueous matrices must be demonstrated.1.2 T
4、his test method is applicable to a wide range of organiccompounds that have sufficiently high volatility and low watersolubility to be efficiently removed from water samples usingpurge and trap procedures. Table 1 lists the compounds thathave been validated for this test method.This test method is n
5、otlimited to the compounds listed in Table 1; however, theapplicability of the test method to other compounds must bedemonstrated.1.3 Analyte concentrations up to approximately 200 g/Lmay be determined without dilution of the sample. Analytesthat are inefficiently purged from water will not be detec
6、tedwhen present at low concentrations, but they can be measuredwith acceptable accuracy and precision when present in suffi-cient amounts.1.4 Analytes that are not separated chromatographically, butthat have different mass spectra and noninterfering quantitationions, can be identified and measured i
7、n the same calibrationmixture or water sample. Analytes that have very similar massspectra cannot be individually identified and measured in thesame calibration mixture or water sample unless they havedifferent retention times. Coeluting compounds with verysimilar mass spectra, such as structural is
8、omers, must bereported as an isomeric group or pair.Two of the three isomericxylenes are examples of structural isomers that may not beresolved on the capillary column, and if not, must be reportedas an isomeric pair.1.5 It is the responsibility of the user to ensure the validityof this test method
9、for untested matrices.1.6 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.7 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 sta
10、ndard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD2777 Practice for Determination of Precision and Bias ofApplicable Test Methods of Commit
11、tee D19 on WaterD3871 Test Method for Purgeable Organic Compounds inWater Using Headspace SamplingD3973 Test Method for Low-Molecular Weight Haloge-nated Hydrocarbons in WaterD4210 Practice for Intralaboratory Quality Control Proce-dures and a Discussion on Reporting Low-Level Data3E355 Practice for
12、 Gas Chromatography Terms and Rela-tionships2.2 Other Document:Code of Federal Regulations 40 CFR Part 26143. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, referto Definitions D1129 and Practice E355.3.2 Definitions of Terms Specific to This Standard:3.2.1 calib
13、ration standarda solution prepared from theprimary dilution standard solution and stock standard solutionsof the internal standards and surrogate analytes.The calibration1This test method is under the jurisdiction of ASTM Committee D19 on Waterand is the direct responsibility of Subcommittee D19.06
14、on Methods forAnalysis forOrganic Substances in Water.Current edition approved June 15, 2012. Published June 2012. Originallyapproved in 1995. Last previous edition approved in 2006 as D5790 95 (2006).DOI: 10.1520/D5790-95R12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orco
15、ntact 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 the Superintendent of Do
16、cuments, U.S. Government PrintingOffice, Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.standards are used to calibrate the instrument response withrespect to analyte concentration.3.2.2 field duplicates two sep
17、arate samples collected atthe same time and place under identical circumstances andtreated exactly the same throughout field and laboratoryprocedures. Analysis of field duplicates gives an indication ofthe precision associated with sample collection, preservation,and storage, as well as with laborat
18、ory procedures.3.2.3 field reagent blankreagent water placed in a samplecontainer, taken to the field along with the samples, and treatedas a sample in all respects, including exposure to sampling siteconditions, storage, preservation, and all analytical procedures.The purpose of the field reagent b
19、lank is to determine if testmethod analytes or other interferences are present in the fieldenvironment.3.2.4 internal standarda pure analyte added to a solutionin a known amount, that is used to measure the relativeresponses of other test method analytes and surrogates that arecomponents of the same
20、 solution. The internal standard mustbe an analyte that is not a sample component.3.2.5 laboratory duplicatestwo sample aliquots taken inthe analytical laboratory and analyzed separately with identicalprocedures. Analysis of laboratory duplicates gives an indica-tion of the precision associated with
21、 laboratory procedures, butnot with sample collection, preservation, or storage procedures.3.2.6 laboratory-fortified blankan aliquot of reagentwater to which known quantities of the test method analytes areadded in the laboratory. The laboratory-fortified blank isanalyzed exactly like a sample, and
22、 its purpose is to determinewhether the methodology is in control and whether thelaboratory is capable of making accurate and precise measure-ments at the required detection limit.3.2.7 laboratory-fortified sample matrixan aliquot of anenvironmental sample to which known quantities of the testmethod
23、 analytes are added in the laboratory. The laboratory-fortified sample matrix is analyzed exactly like a sample, andits purpose is to determine whether or not the sample matrix orthe addition of preservatives or dechlorinating agents to thesample contributes bias to the analytical results. The back-
24、ground concentrations of the analytes in the sample matrixmust be determined in a separate aliquot, and the measuredvalues in the laboratory-fortified sample matrix must becorrected for background concentrations.3.2.8 laboratory performance check solutiona solution ofone or more compounds (analytes,
25、 surrogates, internal stan-dard, or other test compounds) used to evaluate the perfor-mance of the instrument system with respect to a defined set oftest method criteria.3.2.9 laboratory reagent blankan aliquot of reagent waterthat is treated exactly as a sample including exposure to allglassware, e
26、quipment, solvents, reagents, internal standards,and surrogates that are used with other samples. The laboratoryreagent blank is used to determine if test method analytes orother interferences are present in the laboratory environment,the reagents, or the apparatus.3.2.10 primary dilution standard s
27、olutiona solution ofseveral analytes prepared in the laboratory from stock standardsolutions and diluted as needed to prepare calibration solutionsand other needed analyte solutions.3.2.11 purgeable organicany organic material that isremoved from aqueous solution under the purging conditionsdescribe
28、d in this test method.3.2.12 quality control samplea sample matrix containingtest method analytes or a solution of method analytes in awater-miscible solvent that is used to fortify reagent water orenvironmental samples. The quality control sample is obtainedfrom a source external to the laboratory
29、and is used to checklaboratory performance with externally prepared test materials.3.2.13 stock standard solutiona concentrated solutioncontaining a single certified standard that is a test methodanalyte prepared in the laboratory with an assayed referencecompound. Stock standard solutions are used
30、to prepareprimary dilution standards. Commercially available stock stan-dard solutions may be used.3.2.14 surrogate analytea pure analyte that is extremelyunlikely to be found in any sample, that is added to a samplealiquot in a known amount, and is measured with the sameprocedures used to measure o
31、ther components. The purpose ofa surrogate analyte is to monitor test method performance witheach sample.4. Summary of Test Method4.1 Volatile organic compounds with low water-solubilityare purged from the sample matrix by bubbling an inert gasthrough the aqueous sample. Purged sample components are
32、trapped in a tube containing suitable sorbent materials. Whenpurging is complete, the sorbent tube is heated and backflushedwith inert gas to desorb the trapped sample components into acapillary gas chromatography (GC) column interfaced to amass spectrometer (MS). The GC column is temperatureprogram
33、med to separate the test method analytes which arethen detected with the MS. Compounds eluting from the GCcolumn are identified by comparing their measured massspectra and retention times to reference spectra and retentiontimes in a database. Reference spectra and retention times foranalytes are obt
34、ained by the measurement of calibrationstandards under the same conditions used for the samples. Theconcentration of each identified component is measured byrelating the MS response of the quantitation ion produced bythat compound to the MS response of the quantitation ionproduced by a compound that
35、 is used as an internal standard.Surrogate analytes, whose concentrations are known in everysample, are measured with the same internal standard calibra-tion procedure.5. Significance and Use5.1 Purgeable organic compounds have been identified ascontaminants in treated drinking water, wastewater, gr
36、oundwater, and Toxicity Characteristic Leaching Procedure (TCLP)leachate. These contaminants may be harmful to the environ-ment and to people. Purge and trap sampling is a generallyapplicable procedure for concentrating these components priorto gas chromatographic analysis.D5790 95 (2012)26. Interfe
37、rences6.1 During analysis, major contaminant sources are volatilematerials in the laboratory and impurities in the inert purginggas and in the sorbent trap. Avoid the use of plastic tubing orthread sealants other than PTFE, and avoid the use of flowcontrollers with rubber components in the purging d
38、evice.These materials out-gas organic compounds that will beconcentrated in the trap during the purge operation. Analysesof laboratory reagent blanks provide information about thepresence of contaminants. When potential interfering peaks arenoted in laboratory reagent blanks, the analyst should chan
39、gethe purge gas source and regenerate the molecular sieve purgegas filter. Reagents should also be checked for the presence ofcontaminants. Subtracting blank values from sample results isnot permitted.6.2 Interfering contamination may occur when a samplecontaining low concentrations of volatile orga
40、nic compounds isanalyzed immediately after a sample containing higher con-centrations of volatile organic compounds. Experience gainedfrom the test method validation has shown that there is acarryover of approximately 2 % of the concentration of eachanalyte from one sample to the next. The effect wa
41、s observedwhen samples containing 1 g/L of analyte were analyzedimmediately after samples containing 20 g/L of analyte. Forthat reason, when low concentrations of analytes are measuredin a sample, it is very important to examine the results of thepreceding samples and interpret the low-concentration
42、 resultsaccordingly. One preventive technique is between-sample rins-ing of the purging apparatus and sample syringes with twoportions of reagent water.After analysis of a sample containinghigh concentrations of volatile organic compounds, one ormore laboratory reagent blanks should be analyzed to c
43、heck forcross contamination. After analyzing a highly contaminatedsample, it may be necessary to use methanol to clean thesample chamber, followed by heating in an oven at 105C.6.3 Samples can be contaminated by diffusion of volatileorganics through the septum seal into the sample duringshipment and
44、 storage. The analytical and sample storage areashould be isolated from all atmospheric sources of volatileorganic compounds, otherwise random background levels mayresult. Since methylene chloride will permeate through PTFEtubing, all gas chromatography carrier gas lines and purge gasplumbing should
45、 be constructed of stainless steel or coppertubing. Personnel who have been working directly with sol-vents such as those used in liquid/liquid extraction proceduresshould not be allowed into the analytical area until they havewashed and changed their clothing.TABLE 1 Compounds Validated for This Te
46、st MethodCompound CAS Registry Number Primary Quantitation IonSecondary QuantitationIonApproximate ElutionOrderBenzene 71-43-2 78 77 20Bromobenzene 108-86-1 156 77, 158 44Bromochloromethane 74-97-5 128 49, 130 16Bromodichloromethane 75-27-4 83 85, 127 25Bromoform 75-25-2 173 175, 252 41Bromomethane
47、74-83-9 94 96 4n-butylbenzene 104-51-8 91 134 57sec-butylbenzene 135-98-8 105 134 53tert-butylbenzene 98-06-6 119 91 52Carbon disulfide 75-15-0 76 78 8Carbon tetrachloride 56-23-5 117 119 19Chlorobenzene 108-90-7 112 77, 114 35Chloroethane 75-00-3 64 66 5Chloroform 67-66-3 83 85 15Chloromethane 74-8
48、7-3 50 52 22-chlorotoluene 95-49-8 91 126 474-chlorotoluene 106-43-4 91 126 50Dibromochloromethane 124-48-1 129 127 331,2-dibromo-3-chloropropane 96-12-8 75 155, 157 601,2-dibromoethane 106-93-4 107 109, 188 34Dibromomethane 74-95-3 93 95, 174 261,2-dichlorobenzene 95-50-1 146 111, 148 581,3-dichlor
49、obenzene 541-73-1 146 111, 148 541,4-dichlorobenzene 106-46-7 146 111, 148 56trans-1,4-dichloro-2-butene 110-57-6 75 53, 89 48Dichlorodifluoromethane 75-71-8 85 87 11,1-dichloroethane 75-34-3 63 65, 83 111,2-dichloroethane 107-06-2 62 98 211,1-dichloroethene 75-35-4 96 61, 63 7cis-1,2-dichloroethene 156-59-4 96 61, 98 13trans-1,2-dichloroethene 156-60-5 96 61, 98 101,2-dichloropropane 78-87-5 63 112 241,3-dichloropropane 142-28-9 76 78 322,2-dichloropropane 590-20-7 77 97 121,1-dichloropropene 563-58-6 75 110, 77 18cis-1,3-dichloropropene 10061-01-5 75 110 27trans-
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