Designation:D4198−82(Reapproved2011)StandardTestMethodsforEvaluatingAbsorbentPadsUsedwithMembraneFiltersforBacteriologicalAnalysisandGrowth1ThisstandardisissuedunderthefixeddesignationD4198;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thesetestmethodscoverthedeterminationofthenutrient-holdingcapacityandthetoxicornutritiveeffectonbacterialgrowthoforganismsretainedonamembranefilter,whentheabsorbentpadbeingtestedisusedasanutrientreservoirandmediumsupplysourcefortheretainedbacteria.1.2Thetestsdescribedareconductedon47-mmdiameterdisks,althoughothersizedisksmaybeemployedforbacterialculturetechniques.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D1129TerminologyRelatingtoWaterD1193SpecificationforReagentWaterD3508MethodforEvaluatingWaterTestingMembraneFiltersforFecalColiformRecovery(Discontinued1994)(Withdrawn1995)33.Terminology3.1Definitions—Fordefinitionsoftermsusedinthesetestmethods,refertoTerminologyD1129.4.SummaryofTestMethods4.1TestMethodAinvolvessaturatinga47-mmabsorbentpadwithwateranddeterminingthevolumeofwaterheldbythepadbyweighingthepaddryandwhenfullysaturated.4.2TestMethodBinvolvesculturingmicro-organismsfromsuspensionsofpureculturesona0.45-µmmembranefilter,whichisplacedonthetestabsorbentpadsaturatedwiththeappropriategrowthmedium.Theresultantculturesarecom-paredtoculturesgrownonspreadplatesandtomembranefiltersplaceddirectlyonagarwithnoabsorbentpad.5.SignificanceandUse5.1Thesetestmethodsareappropriateforqualifyingabsor-bentpadsusedwithmembranefiltersforbacteriologicalenumeration.5.1.1Thetestmethodsdescribedar...
