1、Designation: D8028 17Standard Test Method forMeasurement of Dissolved Gases Methane, Ethane,Ethylene, and Propane by Static Headspace Sampling andFlame Ionization Detection (GC/FID)1This standard is issued under the fixed designation D8028; the number immediately following the designation indicates
2、the year oforiginal 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 the
3、 dis-solved gases methane, ethane, ethylene, and propane indrinking, waste, and ground waters, including domestic wellswhether naturally occurring or resulting from commercialactivities, or both. This test method has an analytical rangefrom 10 g/L to 11 000 g/L for methane, and 10 g/L to 5000g/L for
4、 ethane, ethylene, and propane. If a sample has adissolved gas concentration above the calibration range, thesample would require dilution. Other analytical ranges may beused as long as the instrument calibration encompasses thedesired range and demonstrates adequate linearity.1.2 This test method i
5、s applicable to samples collected at anominal ambient pressure. Samples collected under highpressures, that is, above ambient pressure, may not be accu-rately analyzed using this method.1.3 This test method is applicable to a variety of dissolvedgases; however, for the present standard, only methane
6、, ethane,ethylene, and propane were validated. In order to validate fora gas not listed in this method, the analyst would need toestablish the saturation concentration of the new gas, andestablish a valid curve, method detection limits, and demon-stration of capability following the procedures outli
7、ned in thismethod.1.4 It is the analysts responsibility to ensure the validity ofthis test method for dissolved gases other than methane, ethane,ethylene, and propane and other sample matrices.1.5 UnitsThe values stated in SI units are to be regardedas the standard. No other units of measurement are
8、 included inthis standard.1.6 A single laboratory study was done in order to establishprecision and bias for the surrogate (see Section 16).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 standard t
9、o establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Prin
10、ciples for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD8006 Guide for Sampl
11、ing and Analysis of Residential andCommercial Water Supply Wells in Areas of Explorationand Production (E&P) OperationsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE355 Practice for Gas Chromatography Terms and Relation-shipsE691 Practice for Conducting an Interlaboratory
12、 Study toDetermine the Precision of a Test Method2.2 Federal Standards:40 CFR Part 136, Appendix B Definition and Procedure forthe Determination of the Method Detection Limit, Revi-sion 1.113PA-DEP 3686 Light Hydrocarbons in Aqueous Samples viaHeadspace and Gas Chromatography with Flame Ioniza-tion
13、Detection (GC/FID), Revision 0, April 20124SW-846 Test Methods for Evaluating Solid Waste: Physical/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 Water.Current edition
14、approved Nov. 1, 2017. Published December 2017. DOI:10.1520/D8028-17.2For 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
15、website.3Available from U.S. Government Printing Office, Superintendent ofDocuments, 732 N. Capitol St., NW, Washington, DC 20401-0001, http:/www.access.gpo.gov.4Available from Pennsylvania Department of Environmental Protection (PA-DEP), Headquarters, Rachel Carson State Office Building, 400 Market
16、 Street,Harrisburg, PA 17101, http:/www.dep.state.pa.us.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established i
17、n the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1Chemical Methods, Update V, Chapter Four, Revision 5,July 20145SW-846, Method 5021 Volatile Organic Compounds in
18、Vari-ous Sample Matrices Using Equilibrium HeadspaceAnalysis, Update V, Revision 2, July 201463. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this standard, refer toTerminology D1129 and Practice E355.3.2 Definitions of Terms Specific to This Standard:3.2.1 batch, nset (group) o
19、f up to 20 samples analyzedsuch that results of analysis of the quality control (QC) samplesanalyzed with the batch are indicative of the quality of theresults of analysis of samples in the batch.3.2.1.1 DiscussionThe number of samples in the batch isdefined by the task group responsible for the met
20、hod or asdefined by laboratory quality assurance (QA) practices.3.2.2 calibration standard, nsolution containing the ana-lyte(s) of interest at a known concentration either purchasedfrom a certified reference material provider or prepared in-house from materials of known purity and concentration and
21、used to calibrate the measurement system.3.2.3 calibration verification standard, CV, ndefined stan-dard used to verify the accuracy of a calibration in themeasurement range of interest.3.2.3.1 DiscussionThe CV should be obtained from acertified reference material provider or prepared at the labora-
22、tory from a separate source from the calibration standards. Thisstandard may not be used to perform calibrations, only cali-bration verification.3.2.4 field duplicates, ntwo separate samples collected atthe same time and place under identical circumstances andtreated exactly the same throughout fiel
23、d and laboratoryprocedure.3.2.4.1 DiscussionAnalysis of field duplicates gives anindication of the precision associated with sample collection,preservation, and storage, as well as with laboratory proce-dures.3.2.5 field reagent blank, nreagent water placed in asample container taken to the field al
24、ong with the samples andtreated as a sample in all respects, including exposure tosampling procedures, sampling site conditions, storage,preservation, and all analytical procedures.3.2.5.1 DiscussionThe purpose of the field reagent blankis to determine if test method or instrument analytes, or both,
25、or other interferences are present in the field environment.3.2.6 initial calibration, ICAL, standard solutions, nset ofsolutions containing the target analytes at concentrations thatdefine the calibration range of the method.3.2.7 laboratory control standard, LCS, naliquot of solu-tion with known c
26、oncentrations of method analytes.3.2.7.1 DiscussionIt should be obtained from a certifiedreference material provider or prepared at the laboratory. TheLCS is analyzed using the same sample preparation, analyticalmethod, and QA/QC procedure used for test samples. Itspurpose is to determine whether me
27、thod performance is withinaccepted control limits.3.2.8 laboratory control standard duplicate, LCSD,nsecond aliquot of solution with known concentrations ofmethod analytes. (See 3.2.7.1, Discussion for laboratory con-trol standard.)3.2.9 matrix spike, MS, nsecond aliquot of a sample towhich known co
28、ncentrations of target analyte(s) are added inthe laboratory and should be analyzed using the same samplepreparation and analytical method used for test samples.3.2.9.1 DiscussionMS should be prepared by diluting thesample with a known concentration of prepared laboratorystandard. Its purpose is to
29、determine whether the sample matrixcontributes bias to the analytical results.3.2.10 method blank, MB, nsuitable aliquots of reagentwater, analyzed using the same sample preparation technique,analytical method, and QA/QC procedure used for testsamples.3.2.10.1 DiscussionThe MB is used to determine i
30、fmethod analytes or other interferences are present in thelaboratory environment, the reagents, or apparatus.3.2.11 method detection limit, MDL, nthe minimum con-centration of an analyte that can be identified, measured, andreported with a 99 % confidence that the analyte concentrationis greater tha
31、n zero.3.2.11.1 DiscussionThe confidence level is determinedfrom analysis of a sample in a given matrix containing theanalyte(s).3.2.12 saturation, npoint at which a solution containsenough of a dissolved solid, liquid, or gas so that no more willdissolve in the solution at a given temperature and p
32、ressure.3.2.13 stock standard solution, nconcentrated solutioncontaining a single certified standard that is a test methodanalyte prepared in the laboratory with an assayed referencecompound.3.2.13.1 DiscussionStock standard solutions are used toprepare primary dilution standards.3.2.14 surrogate an
33、alyte, npure analyte(s), which is ex-tremely unlikely to be found in any sample, and is added to thesample aliquot in known amount(s) before extraction andmeasured with the same procedures used to measure othersample components.3.3 Acronyms:3.3.1 FID, nflame ionization detector3.3.2 GC, ngas chromat
34、ograph3.3.3 ICAL, adjinitial calibration3.3.4 LCS, nlaboratory control standard3.3.5 LCSD, nlaboratory control standard duplicate3.3.6 MB, nmethod blank5Available from United States Environmental ProtectionAgency (EPA), WilliamJefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460
35、,http:/www.epa.gov.6Available from United States Environmental ProtectionAgency (EPA), WilliamJefferson Clinton Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460,http:/www.epa.gov.D8028 1723.3.7 MS, nmatrix spike3.3.8 MSD, nmatrix spike duplicate3.3.9 PLOT, adjporous layer open tubular3.3.10 Q
36、A, adjquality assurance3.3.11 QC, adjquality control3.3.12 PA-DEP, nPennsylvania Department of Environ-mental Protection3.3.13 RSD, nrelative standard deviation3.3.14 RSK, nRobert S. Kerr3.3.15 UHP, adjultra high purity4. Summary of Test Method4.1 A headspace is made in the sample vial without expos
37、-ing the sample to atmosphere. The sample is then stirred oragitated and brought to constant temperature to facilitatepartitioning of the dissolved gases into the established head-space. Once temperature control and stirring or agitationparameters are established, EVERY sample, standard, andblank ne
38、eds to be temperature controlled and stirred or agitatedin the exact same way in order to ensure reproducibility. Aportion of the headspace is then injected onto the head of a gaschromatographic (GC) column for separation and analysis.Measurement is accomplished using a flame ionization detector(FID
39、).5. Significance and Use5.1 This test method covers the determination of the dis-solved gases methane, ethane, ethylene, and propane indrinking, waste, and ground waters, including domestic wells;whether naturally occurring or resulting from commercialactivities, dissolved gases can be hazardous bo
40、th to theenvironment and humans. Due to increased scrutiny of dis-solved gases, developing a valid method for the testing ofdissolved gases in water has become more imperative. Staticheadspace sampling is generally applicable for sampling thesecompounds. However, as these compounds are extremelyvola
41、tile, a closed sampling system is recommended. This testmethod can be used for quantitatively determining dissolvedgases in ground, waste, and drinking waters.5.2 This test method is suitable for analysis of domesticdrinking water samples from residential and commercial watersupply wells prior to oi
42、l and gas exploration activities to forma baseline for monitoring potential impacts during exploration;development, including hydraulic fracturing; operation; clo-sure; and reclamation of nearby oil and gas production andinjection wells.6. Interferences6.1 Impurities in the air, the field sample via
43、ls, vial septa,the preservatives, or improper sealing during transport cancause contamination. Field reagent blanks, recommended, andmethod blanks, required, shall be used to verify propersampling and handling procedures.6.2 Contamination or carryover can occur whenever ahighly concentrated sample i
44、s run. A blank shall be run after ahighly concentrated sample to ensure system cleanliness.6.2.1 A carryover study should be done in order to deter-mine the nominal level of analytes that will be prone to carryover into subsequent samples. From this study, the laboratoryshall be required to run blan
45、ks after samples containinganalytes above the established levels. Otherwise, if a sample isrun directly after a high level sample, reference the laboratorycarryover study, and displays an analyte of interest, the samplewould need to be run again in order to ensure the accuracy ofthe results.6.3 The
46、FID is a nonselective detector. If matrix interferencecaused by sample contamination or compound co-elutionoccurs, an experienced analyst is required for proper interpre-tation.6.4 In order to inhibit analyte loss, samples should be storedin 40-ml vials with polytetrafluoroethylene (PTFE)-lined chlo
47、-robutyl septa with no headspace, and placed on ice within 15minutes of collection. Samples should be transported and keptcooled to approximately 0 to 6C but not frozen. If any visibleheadspace exists in a sample vial, it is to be noted in the resultsreport as analyte loss can exist with sample head
48、space.Samples may be preserved with sulfuric acid in order to extendthe expiration date to two weeks from the sampling date.7. Apparatus7.1 Sample containers, 40-ml screw top vials sealed withPTFE-lined chlorobutyl septa.7.2 Water bath, capable of maintaining water temperature at20C (60.5C) to prepa
49、re calibration and laboratory controlstandards. Temperatures other than 20C may be used, as longas the saturated solution concentration at the temperature isknown.7.3 Digital thermometer.7.4 Gastight syringes, 10 l to 2.5 ml.7.5 Two gastight syringes fitted with removable needles andLuer lock valves, 25 ml.7.6 Glass-stoppered class A volumetric flasks, 5 to 100 ml.7.7 Stir bars, (required only for sample agitation throughstirring) magnetic stir bars sized to fit in the 40-ml screw-topvials.7.8 Ultra high purity (UHP) inert
