1、Designation:D 3057 94Standard Test Method forMoisture in Aerosol Products1This standard is issued under the fixed designation D 3057;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 in
2、dicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This test method covers the determination of moisture inaerosol products.1.2 This
3、 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.A specific warningstatemen
4、t is given in Note 1.2.Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water23.Summary of Test Method3.1 Moisture is determined in an aerosol product by back-titrating the specimen,to which Karl Fischer reagent has beenadded,with a methanol-water solution.A ratio between them
5、ethanol and Karl Fischer reagent is obtained,and the KarlFischer reagent is standardized against sodium tartrate dihy-drate.4.Significance and Use4.1 Moderate concentration of water in certain aerosolformulations can lead to metallic can corrosion.NOTE1Warning:Contaminated primary alcohols with wate
6、r levelsof 1 to 2%can produce hydrogen gas in aluminum containers causingthem to rupture.4.2 Ketones,such as acetone,can produce falsely highresults.5.Apparatus5.1 Closed Containers,glass,three.5.2 Stirrer,magnetic.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unl
7、ess otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently h
8、igh purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean water conforming toSpecification D 1193.6.3 Karl Fischer Reagent.6.4 MethanolAnhydrous methyl alcohol.46.5 Methanol-Water Stand
9、ard Solution.6.6 Sodium Tartrate Standard(Na2C4H4O62H2O).7.Sampling7.1 Obtain production made samples selected at random.8.Standardization8.1 Ratio of Karl Fischer Reagent to Methanol-Water Solu-tion:8.1.1 Place approximately 60 mL of methanol into a closedglass container,and add from 2 to 3 mL of K
10、arl Fischerreagent.Agitate the solution with the magnetic stirrer forapproximately 5 min.8.1.2 Back-titrate the solution with the methanol-watersolution until the end point is reached;then add 10 mL of KarlFischer reagent.Back-titrate with the methanol-water soutionuntil the end point is reached.8.1
11、.3 Calculate the ratio of Karl Fischer reagent tomethanol-water solution,X,as follows:X 5 A/Bwhere:A 5 Karl Fischer reagent used,mL,andB 5 methanol-water solution used,mL.NOTE2A ratio close to 1 is recommended.8.2 Standardization of Karl Fischer Reagent:1This test method is under the jurisdiction of
12、 ASTM Committee D-10 onPackaging and is the direct responsibility of Subcommittee D10.32 on ConsumerPackages.Originally developed by the Chemical Specialties Manufacturers Assn.Current edition approved Nov.15,1994.Published January 1995.Originallypublished as D 3057 72.Last previous edition D 3057 8
13、0(1986)e1.2Annual Book of ASTM Standards,Vol 11.01.3“Reagent Chemicals,American Chemical Society Specifications,”Am.Chemi-cal Soc.,Washington,DC.For suggestions on the testing of reagents not listed bytheAmerican Chemical Society,see“Reagent Chemicals and Standards,”by JosephRosin,D.Van Nostrand Co.
14、,Inc.,New York,NY,and the“United StatesPharmacopeia.”4Bakers Analyzed Anhydrous Methanol(approximately 0.05%water),avail-able from Baker Chemical Co.,has been found satisfactory for this method.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from th
15、e Annual Book of ASTM Standards.Copyright ASTMNOTICE:Thisstandardhaseitherbeensupersededandreplacedbyanewversionordiscontinued.ContactASTMInternational(www.astm.org)forthelatestinformation.8.2.1 Place approximately 60 mL of methanol into a closedglass container and add from 2 to 3 mLof Karl Fischer
16、reagent.Agitate the solution for 5 min with the magnetic stirrer.8.2.2 Back-titrate the solution with the methanol-watersolution until the end point is reached.Add 0.32 g of sodiumtartrate and approximately 6 mL of Karl Fischer reagent.Agitate until the sodium tartrate is completely dissolved,thenback-titrate with the methanol-water solution until the endpoint is reached.8.2.3 Calculate the millilitres of Karl Fischer reagent used tocombine with the water in the sodium tartrate standard,C,asfoll
