1、Designation:E122809Standard Test Method forAssay of Peroxy EstersCatalyzed Iodometric Procedure1This standard is issued under the fixed designation E1228;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A num
2、ber 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 covers the assay of organic peroxidesof the peroxy ester type.NOTE1Other test methods for the assay of organic peroxides are
3、given in Test Methods E298,E475,and E755.1.2 Review the current material safety data sheets(MSDS)for detailed information concerning toxicity,first aidprocedures,and safety precautions.1.3 The values stated in SI units are to be regarded as thestandard.No other units of measurement are included in t
4、histest method.1.4 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.Spe
5、cific hazardsstatements are given in Section 9.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)3E200 Practice for Preparation,Stand
6、ardization,and Storageof Standard and Reagent Solutions for Chemical AnalysisE298 Test Methods for Assay of Organic PeroxidesE475 Test Method for Assay of Di-tert-Butyl PeroxideUsing Gas ChromatographyE755 Test Method for Dicumyl Peroxide,Assay(LiquidChromatography)3.Terminology3.1 Definitions:3.1.1
7、 active oxygenthe oxidizing power present in organicperoxides expressed as oxygen(equivalent weight 8.00).4.Summary of Test Method4.1 A sample is dissolved in a mixture of isopropyl alcohol,acetic acid,and cupric chloride.Asolution of potassium iodideis added and the mixture is briefly heated,then a
8、llowed to reactin the dark at room temperature for 30 min.The cupric ioncatalyzes the reduction of the peroxide and the liberated iodineis titrated with standard sodium thiosulfate solution.5.Significance and Use5.1 Peroxyestersarewidelyusedaschemicalintermediates,catalysts,and initiators.This test
9、method pro-vides a procedure for assaying peroxy esters to determine ifthey are suitable for their intended use.6.Interferences6.1 Conjugated diolefins interfere under the conditions ofanalysis by absorbing iodine.7.Apparatus7.1 Iodine Flasks,250-mL capacity,with stoppers.NOTE2All glassware should b
10、e cleaned thoroughly with dichromatecleaning solution before use.7.2 Beakers,1-mL capacity,glass or PTFE.7.3 Buret,50-mL capacity,graduated in 0.1-mL subdivi-sions.7.4 Water Bath,maintained at 60C.8.Reagents8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indi
11、cated,it is intended thatall reagents shall conform to the Specifications of the Com-mittee on Analytical Reagents of the American Chemical1This test method is under the jurisdiction of ASTM Committee E15 onIndustrial and Specialty Chemicalsand is the direct responsibility of SubcommitteeE15.01 on G
12、eneral Standards.Current edition approved April 1,2009.Published April 2009.Originallyapproved in 1988.Last previous edition approved in 2003 as E1228-94(2003)1.DOI:10.1520/E1228-09.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.
13、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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Ba
14、rr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Society,where such specifications are available.4Other gradesmay be used,provided it is first ascertained that the reagent isof sufficiently high purity to permit its use without lesseningthe accuracy of the determination.8.2
15、 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean Type II or III reagentwater conforming to Specification D1193.8.3 Acetic Acid,glacial.8.4 Isopropyl Alcohol.8.5 Hydrochloric Acid,(1:100)Dilute 1.0 mL of concen-trated hydrochloric acid(HCl)to 100 mL with water
16、.8.6 Cupric Chloride Solution,1%Dilute 1.0 g of anhy-drous cupric chloride(CuCl2)to 100 mL with water.Add 1.0mL of 1:100 HCl and mix.The solution should be clear.8.7 Potassium Iodide Solution,50%Dissolve 25 g ofpotassium iodide(KI)in 25 mL of de-aerated water.Thisreagent should be freshly prepared just prior to use.8.8 Sodium Thiosulfate Standard Solution,(0.1 meq/mL)Prepare and standardize in accordance with the appropriatesections of Practice E200.8.9 Nitrogen Gas,oxygen-free.9.Hazards9.1 Orga