ASTM_D_4199_-_82_2011.pdf

Designation:D419982(Reapproved 2011)Standard Test Methods forAutoclavability of Membrane Filters1This standard is issued under the fixed designation D4199;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 deal with tests to determine theautoclavability of membrane filters.1.2 These test methods are applicable to all membranefilters.Either Test Method A,Test Method B,or both,may beutilized to assess the autoclavability of membrane filters.SectionTest Method ADimensional Stability8.1Test Method BWetting Characteristics8.21.3 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 Water3.Terminology3.1 DefinitionsFor definitions of terms used in these testmethods,refer to Terminology D1129.4.Summary of Test Methods4.1 Test Method AAutoclavability is evaluated by measur-ing the diameter of the membrane filter,across three axes,priorto autoclaving and after autoclaving,to determine dimensionalstability.4.2 Test Method BWettability is determined by placingsamples of autoclaved and nonautoclaved membrane filters inwater and measuring the time required for the filters to becomecompletely wet.5.Significance and Use5.1 These test methods provide information on the dimen-sional stability and wetting characteristics of autoclaved mem-brane filters.Excessive dimensional changes caused by auto-claving a constrained membrane filter could crack the filter,rendering it useless.Increased hydrophobicity,due to autoclav-ing would result in an increased time to filter a liquid sample.6.Apparatus6.1 Calipers,accurate to 0.1 mm.6.2 Holder,suitable for membrane filters.6.3 Autoclave.6.4 Petri Dish.6.5 Forceps,nonserrated.6.6 Stopwatch,accurate to 0.1 s.7.Purity of Reagents7.1 Water used in these test methods should be reagentgrade Type IV B of Specification D1193 or higher quality.8.Procedure8.1 Test Method ADimensional Stability:8.1.1 Measure the diameter of nonautoclaved filters,acrossthree axes,with the calipers.Use three disks for each test.8.1.2 Wrap filters in suitable autoclave packaging and auto-clave at 121C for 10 min.8.1.3 Remove the packaged filter disks from the autoclaveafter the slow exhaust cycle and allow to equilibrate to ambienttemperature.8.1.4 Measure the diameter of the disks as in 8.1.1.8.2 Test Method BWetting Characteristics:8.2.1 Partially fill a petri dish with water containing 1%methylene blue dye.Allow the water to equilibrate to ambienttemperature.8.2.2 Using nonserrated forceps,place a nonautoclavedmembrane filter disk onto the water surface.8.2.3 Start the stopwatch as soon as the filter is placed ontothe water surface.8.2.4 Record the time for filter to wet uniformly.If there arenonwetting areas,refer to 8.2.6.8.2.5 Repeat wetting test with membrane filters autoclavedas in 8.1.1,8.1.2,and 8.1.3.1These test methods are under the jurisdiction of ASTM Committee D19 onWater and are the direct responsibility of Subcommittee D19.08 on Membranes andIon Exchange Materials.Current edition approved May 1,2011.Published June 2011.Originallyapproved in 1982.Last previous edition approved in 2003 as D4199 82(2003).DOI:10.1520/D4199-82R11.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 8.2.6 Examine the wetted filters for uniformity of wettingand note whether there are any nonwetting areas on the filter.9.Report9.1 Dimensional StabilityReport the average diameter ofeach of the three nonautoclaved filters,and report all diametersmeasured for each filter after autoclaving.9.2 Wetting CharacteristicsReport the wetting time for thenonautoclaved filter and the wetting time for the autoclavedfilter.Report on any wetting irregularities or nonwetting areasobserved on either the nonautoclaved or autoclaved filters.10.Precision and Bias10.1 No statement is made about either the precision or biasof these test methods for determining autoclaving characteris-tics of membrane filters,since the results merely state whetherthere is conformance to the criteria for success specified in theprocedure.11.Keywords11.1 autoclavability;filter;membraneASTM International takes no position respecting the validity of any patent rights asserted in connection