Designation:D5580−21StandardTestMethodforDeterminationofBenzene,Toluene,Ethylbenzene,p/m-Xylene,o-Xylene,C9andHeavierAromatics,andTotalAromaticsinFinishedGasolinebyGasChromatography1ThisstandardisissuedunderthefixeddesignationD5580;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoversthedeterminationofbenzene,toluene,ethylbenzene,thexylenes,C9andheavieraromatics,andtotalaromaticsinfinishedmotorgasolinebygaschroma-tography.1.2Thearomatichydrocarbonsareseparatedwithoutinter-ferencesfromotherhydrocarbonsinfinishedgasoline.Non-aromatichydrocarbonshavingaboilingpointgreaterthann-dodecanemaycauseinterferenceswiththedeterminationoftheC9andheavieraromatics.FortheC8aromatics,p-xyleneandm-xyleneco-elutewhileethylbenzeneando-xyleneareseparated.TheC9andheavieraromaticsaredeterminedasasinglegroup.1.3Thistestmethodcoversthefollowingconcentrationranges,inliquidvolume%,fortheprecedingaromatics:benzene,0.1%to5%;toluene,1%to15%;individualC8aromatics,0.5%to10%;totalC9andheavieraromatics,5%to30%,andtotalaromatics,10%to80%.1.4Resultsarereportedtothenearest0.01%byeithermassorbyliquidvolume.1.5ThistestmethodincludesarelativebiassectionforU.S.EPAspark-ignitionenginefuelregulationsreportingforben-zenebasedonPracticeD6708accuracyassessmentbetweenTestMethodD5580andTestMethodD3606asapossibleTestMethodD5580alternativetoTestMethodD3606.ThePracticeD6708derivedcorrelationequationisonlyapplicableforfuelsinthebenzeneconcentrationrangefrom0.0%to2.31%byvolumeasmeasuredbyTestMethodD5580.TheapplicableTestMethodD3606rangeforbenzeneisfrom0.0%to2.38%byvolumeasreportedbyTestMethodD3606.1.6ThistestmethodincludesarelativebiassectionforU.S.EPAspark-ignitionenginefuelregulationsfortotalaromaticsreportingbasedonPracticeD6708accuracyassessmentbe-tweenTestMethodD5580andTestMethod...
