EPA 9132 TOTAL COLIFORM MEMBRANE-FILTER TECHNIQUE

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1、METHOD9132TOTALCOLIFORM:MEMBRANE-FILTERTECHNIQUE1.0SCOPEANDAPPLICATION1.1Thismethodisusedtodeterminethepresenceofamemberofacoliformgroupinwastewaterandgroundwater.1.2Thecoliformgroupanalyzedinthisprocedureincludesalloftheorganismsthatproduceacolonywithagolden-greenmetallicsheenw

2、ithin24hrofinoculation.2.0SUMMARYOFMETHOD2.1Apredeterminedamountofsampleisfilteredthroughamembranefilterwhichretainsthebacteriafoundinthesample.2.2Inthetwo-stepenrichmentprocedure,thefilterscontainingbacteriaareplacedonanabsorbentpadsaturatedwithlauryltryptosebrothandincubatedat

3、35EC+0.5ECfor2hr.ThefiltersarethentransferredtoanabsorbentpadsaturatedwithM-EndomediaortoadishcontainingM-Endoagarandincubatedforanother21+1hrat35EC+0.5EC.Sheencoloniesarethencountedundermagnificationandreportedper100mLoforiginalsample.2.3Amoredetailedtreatmentofthismethodispres

4、entedinStandardMethodsfortheExaminationofWaterandWastewaterandinMicrobiologicalMethodsforMonitoringtheEnvironment(seeReferences,Section10.0).3.0INTERFERENCES3.1Thepresenceofresidualchlorineorotherhalogencanpreventthecontinuationofbacterialaction.Topreventthisoccurrence,sodiumthi

5、osulfateshouldbeadded.3.2Watersampleshighincopper,zinc,orotherheavymetalscanbetoxictobacteria.Chelatingagentssuchasethylenediaminetetraaceticacid(EDTA)shouldonlybeaddedwhenheavymetalsaresuspectedofbeingpresent.3.3Turbiditycausedbythepresenceofalgaeorotherinterferingmaterialmayno

6、tpermittestingofasamplevolumesufficienttoyieldsignificantresults.Lowcoliformestimatesmaybecausedbythepresenceofhighnumbersofnoncoliformsoroftoxicsubstances.3.4Samplescontaininglargeamountsofsuspendedsolidswillinterferewithcolonygrowthandwiththesubsequentcountingofcoloniesonthefi

7、ltermembrane.Whenthisisthecase,useMethod9131.91321CD-ROMRevision0DateSeptember19864.0APPARATUSANDMATERIALS4.1Dilutionbottlesortubes:4.1.1Usebottlesortubesofresistantglass,preferablyborosili-categlass,closedwithglassstoppersorscrewcapsequippedwithlinersthatdonotproducetoxicorbact

8、eriostaticcompoundsonsterilization.4.1.2Donotus