ASTM_E_1784_-_08.pdf

Designation:E178408Standard Test Method forTotal Peroxides in Acrylonitrile1This standard is issued under the fixed designation E1784;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.Scope*1.1 This test method describes a procedure for determiningthe total peroxide content of acrylonitrile in the range of 0.1 to0.6 mg H2O2/kg acrylonitrile(ppm).Peroxides are an undesir-able impurity in acrylonitrile.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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.Specific hazardstatements are given in Section 7.1.4 Review the current Material Safety Data Sheets(MSDS)for detailed information concerning toxicity,first aidprocedures,and safety precautions.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE60 Practice for Analysis of Metals,Ores,and RelatedMaterials by SpectrophotometryE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)3E200 Practice for Preparation,Standardization,and Storageof Standard and Reagent Solutions for Chemical Analysis3.Summary of Test Method3.1 Peroxides in the sample react with potassium iodide toform the yellow I3ion.The intensity of the color,which isproportional to the concentration of the I3ion,is measured at365 nm.Results are expressed as total peroxides as H2O2.4.Significance and Use4.1 This test method provides for the determination of totalperoxide in acrylonitrile in the range of 0.1 to 0.6 ppm.Onlyperoxides or other oxidants that react under the conditions ofthis test method are measured.5.Apparatus5.1 Spectrophotometer,capable of measuring at 365 nm,5.2 Absorption Cells,1-cm,borosilicate,matched,and5.3 Buret,25-mL capacity.NOTE1Photometers and photometric practice described in this testmethod shall conform to Practice E60.6.Reagents6.1 Purity of ReagentsUnless otherwise indicated,allreagents shall conform to the specifications of the Committeeon Analytical Reagents of the American Chemical Societywhere such specifications are available.4Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterUnless otherwise indicated,referencesto water mean Type II or Type III reagent water conforming toSpecification D1193.6.3 Potassium Iodide.6.4 Acetic Anhydride.6.5 Hydrogen Peroxide,30%.6.6 Acrylonitrile,Peroxide FreePrepare by passing acry-lonitrile through a 2 cm 40 cm glass column packed with 50mL of activated alumina or acid form ion exchange resin.51This test method is under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicals and is the direct responsibility of SubcommitteeE15.02 on Product Standards.Current edition approved Dec.15,2008.Published January 2009.Originallyapproved in 1996.Last previous edition approved in 2002 as E1784 97(2002).DOI:10.1520/E1784-08.2For 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.4Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,DC.For suggestions on the testing of reagents notlisted by the American Chemical Society,see Analar Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.5Rohm and Haas Amberlyst 15 has been found to be suitable or an equivalentresin may be used.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Flow through the column should be approximately 8 to 10 bedvolumes per h.The absorbance obtained by following 9.1through 9.3 should be less than 0.01.Alternative means ofpreparation include extraction with 10%NaOH followed bydistillation.For the extraction technique,extract 100 mL ofacrylonitrile with 50 mL of 10%NaOH,follow with tripleextraction with water.The volume of peroxide free acryloni-trile required for calibration is 500 mL.6.7 Sulfuric Acid Solution,12 meq/mLMeasure 360 mL ofconcentrated sulfuric acid(H2SO4sp gr 1.84)into a 500-mL