Designation:D6729−20StandardTestMethodforDeterminationofIndividualComponentsinSparkIgnitionEngineFuelsby100MetreCapillaryHighResolutionGasChromatography1ThisstandardisissuedunderthefixeddesignationD6729;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthedeterminationofindividualhydrocarboncomponentsofspark-ignitionenginefuelsandtheirmixturescontainingoxygenateblends(MTBE,ETBE,ethanol,andsoforth)withboilingrangesupto225°C.Otherlightliquidhydrocarbonmixturestypicallyencounteredinpetroleumrefiningoperations,suchasblendingstocks(naphthas,reformates,alkylates,andsoforth)mayalsobeanalyzed;however,statisticaldatawasobtainedonlywithblendedspark-ignitionenginefuels.1.2Basedonthecooperativestudyresults,individualcom-ponentconcentrationsandprecisionaredeterminedintherangeof0.01%masstoapproximately30%mass.Theproceduremaybeapplicabletohigherandlowerconcentra-tionsfortheindividualcomponents;however,theusermustverifytheaccuracyiftheprocedureisusedforcomponentswithconcentrationsoutsidethespecifiedranges.1.3Thetestmethodalsodeterminesmethanol,ethanol,t-butanol,methylt-butylether(MTBE),ethylt-butylether(ETBE),t-amylmethylether(TAME)insparkignitionenginefuelsintheconcentrationrangeof1%massto30%mass.However,thecooperativestudydataprovidedsufficientstatis-ticaldataforMTBEonly.1.4Althoughamajorityoftheindividualhydrocarbonspresentaredetermined,someco-elutionofcompoundsisencountered.Ifthistestmethodisutilizedtoestimatebulkhydrocarbongroup-typecomposition(PONA)theuserofsuchdatashouldbecautionedthatsomeerrorwillbeencounteredduetoco-elutionandalackofidentificationofallcomponentspresent.Samplescontainingsignificantamountsofolefinicornaphthenic(forexample,virginnaphthas),orboth,constitu-entsaboven-octanemayreflectsignificanterrorsinPONAtypegroupings.Bas...
