Designation:D2667−95(Reapproved2008)StandardTestMethodforBiodegradabilityofAlkylbenzeneSulfonates1ThisstandardisissuedunderthefixeddesignationD2667;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheDepartmentofDefense.1.Scope1.1Thistestmethod2coversthedeterminationofthedegreeofbiodegradabilityofalkylbenzenesulfonates.Itservesasanindexofthesuitabilityofthesulfonateforgeneraluseasasurfactant.1.2Ingeneral,thistestmethoddistinguishesbetweensul-fonatesinwhichthealkylsidechainsarelinearandthoseinwhichtheyarebranched,sincetheformeraremorereadilybiodegradable.Ifthealkylbenzenesulfonateinfullyformu-latedproductsistobeexamined,itmustbeextractedusingthemethodnotedinAnnexA1.(SeeAppendixX1fordata.)1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.MaterialSafetyDataSheetsareavailableforreagentsandmaterials.Reviewthemforhazardspriortousage.2.ReferencedDocuments2.1ASTMStandards:3E1298GuideforDeterminationofPurity,Impurities,andContaminantsinBiologicalDrugProductsD2330TestMethodforMethyleneBlueActiveSubstances(Withdrawn2011)4E1625TestMethodforDeterminingBiodegradabilityofOrganicChemicalsinSemi-ContinuousActivatedSludge(SCAS)3.SummaryofTestMethod3.1Thesampleisfirstsubjectedtoapresumptivetestbasedonshakeculture.Whennecessary,thesamplemaybesub-jectedtoaconfirmingtestbasedonsemicontinuoustreatmentwithactivatedsludge.3.2Inthepresumptivetest,microorganismsareinoculatedintoaflaskthatcontainsachemicallydefinedmicrobialgrowthmedium(basalmedium)andthesurfactanttobetested.Aerationisaccomplishedbycontinuousshakingoftheflask.Followingtwoadaptivetransfer...
