ASTM_D_4198_-_82_2011.pdf

Designation:D419882(Reapproved 2011)Standard Test Methods forEvaluating Absorbent Pads Used with Membrane Filters forBacteriological Analysis and Growth1This standard is issued under the fixed designation D4198;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods cover the determination of thenutrient-holding capacity and the toxic or nutritive effect onbacterial growth of organisms retained on a membrane filter,when the absorbent pad being tested is used as a nutrientreservoir and medium supply source for the retained bacteria.1.2 The tests described are conducted on 47-mm diameterdisks,although other size disks may be employed for bacterialculture techniques.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD3508 Method for Evaluating Water Testing MembraneFilters for Fecal Coliform Recovery(Discontinued 1994)(Withdrawn 1995)33.Terminology3.1 DefinitionsFor definitions of terms used in these testmethods,refer to Terminology D1129.4.Summary of Test Methods4.1 Test Method A involves saturating a 47-mm absorbentpad with water and determining the volume of water held bythe pad by weighing the pad dry and when fully saturated.4.2 Test Method B involves culturing micro-organisms fromsuspensions of pure cultures on a 0.45-m membrane filter,which is placed on the test absorbent pad saturated with theappropriate growth medium.The resultant cultures are com-pared to cultures grown on spread plates and to membranefilters placed directly on agar with no absorbent pad.5.Significance and Use5.1 These test methods are appropriate for qualifying absor-bent pads used with membrane filters for bacteriologicalenumeration.5.1.1 The test methods described are applicable to qualitycontrol testing of absorbent pads by the suppliers and users ofthese pads and to specification testing of absorbent padsintended for use with membrane filters in bacteriologicalenumeration.5.2 Other pure culture organisms and their appropriateculture medium may be substituted for the E.coli and M-FCmedia for specification testing,as required.6.Apparatus6.1 Filtration Units for membrane filters with side-arm flaskand tubing.6.2 Vacuum Source.6.3 Vortex Mixer or similar mixer.6.4 Forceps,flat-bladed.6.5 Incubator capable of maintaining temperatures of 44.56 0.2C.6.6 Stereoscopic Microscope and Illuminator.6.7 Illuminated Magnifying Stand for counting colonies onagar spread plates.6.8 Hand Tally Counter.6.9 Autoclave.6.10 Analytical Balance readable to the nearest 1 mg.6.11 Petri Dish,50-mm,nonsterile.6.12 Expendable Equipment:6.12.1 Filters(gridded,0.45-m,47-mm)sterile,for watertesting.1These methods are under the jurisdiction of ASTM Committee D19 on Waterand are the direct responsibilities of Subcommittee D19.08 on Membranes and IonExchange Materials.Current edition approved May 1,2011.Published May 2011.DOI:10.1520/D4198-82R11.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.12.2 Absorbent pads(47-mm),sterile for the growth test.6.12.3 Petri dishes,sterile 50-mm and 100-mm.6.12.4 Pipets,sterile,10-mL,0.1 mL graduations,accuracyof 6 5%.6.12.5 Test tubes,sterile,20-mL,with screw caps.6.12.6 Bent glass rod,sterile,for spreading bacterial cul-tures.6.12.7 Burner,for flame sterilization.7.Reagents and Materials7.1 Purity of WaterUnless otherwise indicated,referenceto water shall be understood to mean reagent water conformingto Specification D1193,Type II,with 0.2-m membranefiltration.In addition,suitability tests for determining thebactericidal properties of the reagent grade water should beperformed.7.2 M-FC Agar with Rosolic AcidFecal coliform mediumspecific for the membrane filter technique.7.3 M-FC Broth with Rosolic AcidBroth nutrient forbacterial growth.7.4 Peptone Water,0.1%.7.5 E.coli(ATCC 11229).8.Preparation of Equipment and Materials8.1 Washing and CleaningClean all glassware and filtra-tion equipment thoroughly,using a suitable detergent in hotwater,rinse with hot water,and then rinse in reagent gradewater.Dry the equipment thoroughly prior to sterilization.8.2 Ste