Designation:D7979−17StandardTestMethodforDeterminationofPer-andPolyfluoroalkylSubstancesinWater,Sludge,Influent,EffluentandWastewaterbyLiquidChromatographyTandemMassSpectrometry(LC/MS/MS)1ThisstandardisissuedunderthefixeddesignationD7979;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisprocedurecoversthedeterminationofselectedper-andpolyfluoroalkylsubstances(PFASs)inawatermatrixusingliquidchromatography(LC)anddetectionwithtandemmassspectrometry(MS/MS).Theseanalytesarequalitativelyandquantitativelydeterminedbythismethod.Thismethodadherestoatechniqueknownasselectedreactionmonitoring(SRM)orsometimesreferredtoasmultiplereactionmonitor-ing(MRM).Thisisnotadrinkingwatermethod,performanceofthistestmethodhasnotbeenevaluatedondrinkingwatermatrices.1.2TheMethodDetectionLimit(MDL)2andReportingRange3forthetargetanalytesarelistedinTable1.Thetargetconcentrationforthereportinglimitforthistestmethodwas10ng/Lformostofthetargetanalytesatthetimeofdevelopment.1.2.1Thereportinglimitinthistestmethodistheminimumvaluebelowwhichdataaredocumentedasnon-detects.Thereportinglimitmaybeloweredprovidingyourlabmeetstheminimumperformancerequirementsofthistestmethodatthelowerconcentrations,thismethodisperformancebasedandmodificationsareallowedtoimproveperformance.Analytedetectionsbetweenthemethoddetectionlimitandthereport-inglimitareestimatedconcentrationsandarenotreportedfollowingthistestmethod.Inmostcases,thereportinglimitistheconcentrationoftheLevel1calibrationstandardasshowninTable4forthePFASsaftertakingintoaccountthe50%dilutionwithmethanol.ItisabovetheLevel1calibrationconcentrationforFHEAandFOEA,thesecompoundscanbeidentifiedattheLevel1concentrationbutthestandarddevia-tionamongreplicatesatthislowerspikelevelresultedinahigherreportinglimit.1.3ThevaluesstatedinSIunitsaretobereg...
