ASTM_D_1326_-_94_2000.pdf

Designation:D 1326 94(Reapproved 2000)Standard Test Methods forChemical Analysis of Ammoniacal Copper Arsenate andAmmoniacal Copper Zinc Arsenate1,2This standard is issued under the fixed designation D 1326;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods cover the determination of thechemical analysis of commercial solutions of ammoniacalcopper arsenate.1.1.1 Test Method D 38 covers the sampling of woodpreservatives prior to testing.1.2 The analytical procedures appear in the following order:SectionsAmmonium bicarbonate(calculated as carbonate)20 to 22Ammonia(calculated as anhydrous ammonia)6 to 9Arsenic(calculated as arsenic pentoxide)10 to 11Copper(calculated as copper oxide)13 to 16Zinc(calculated as zinc oxide)17 to 191.3 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:D 38 Test Methods for Sampling Wood Preservatives Priorto Testing3D 1193 Specification for Reagent Water4D 1325 Specification for Ammoniacal Copper Zinc Arsen-ate3D 3873 Test Method for Valency State of the ArsenicComponent of Ammoniacal Copper Arsenate Solutions32.2AWPA Standard:AWPA A2 Standard Methods for Analysis of WaterbornePreservatives and Fire-Retardant Formulations53.Summary of Test Methods3.1 AmmoniaAmmonia is freed from a caustic solution ofthe sample by distillation and absorbed in a measured excess ofsulfuric acid solution.The unreacted sulfuric acid solution istitrated with standardized NaOH solution to determine theammonia reacted with sulfuric acid.3.2 ArsenicA diluted sample is acidified with hydrochlo-ric and hypophosphorous acid to precipitate the arsenic.Thearsenic is volatilized by heating in the presence of sulfuric acid,which is then diluted with water and titrated with a standardsolution of potassium bromate.Arsenic is calculated asAs2O5.3.3 CopperA measured sample is dissolved in hydrochlo-ric acid and reacted with potassium iodide to complex thecopper ion.The solution is then titrated with a standardsolution of sodium thiosulfate.The copper is calculated asCuO.3.4 ZincA diluted and chemically treated sample istreated with a standard solution of potassium ferrocyanide inthe presence of an oxidation-reduction indicator(dipheny-lamine).The zinc is calculated as ZnO.4.Significance and Use4.1 Ammoniacal copper arsenate and ammoniacal copperzinc arsenate for use in the preservative treatment of woodmust conform with Specification D 1325.5.Purity of Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,all reagents shallconform to the specifications of the Committee on AnalyticalReagents of the American Chemical Society,where such1These test methods are under the jurisdiction of ASTM Committee D-7 onWood and are the direct responsibility of Subcommittee D07.06 on Treatments forWood Products.Current edition approved July 15,1994.Published September 1994.Originallypublished as D 1326 54 T.Last previous edition D 1326 87.2The analytical methods and sampling procedures are essentially the same asthose given in theAmerican Wood-PreserversAssn.Standard Methods forAnalysisof Water-Borne Preservatives and Fire-Retardant Formulations(A2-91).Acknowl-edgment is made to theAmerican Wood-PreserversAssociation for its developmentof the subject matter covered in this test.3Annual Book of ASTM Standards,Vol 04.10.4Annual Book of ASTM Standards,Vol 11.01.5Available from American Wood-Preservers Association,P.O.Box 286,Wood-stock,MD 21163-0286.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.specifications are available.6Other grades shall only be usedwhen it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.5.2 Unless otherwise indicated,references to water shall beunderstood to mean reagent water conforming to SpecificationD 1193.AMMONIA6.Apparatus6.1 A typical apparatus for the distillation of ammonia isshown in Fig.1.7.Reagents7.1 Methyl Purple or Methyl Red Indicator SolutionSuitable prepared solutions of methyl purple can be purchased.To prepare the methyl red indicator solution,dissolve 0.1 g ofmethyl red in 50 mL of alcohol(90%),dilute to 100 mL withwater,and filter if necessary.7.2 Phenolphthalein Indicator Solution Dissolve 1 g ofphenolphthalein in 100 mL of alcohol.7.3 Sodium Hydroxide Standard Solution(0.1 N)Dissolve4 g of NaOH in CO2-free water and dilute to 1 L with CO2-freewater.Standardi