ASTM_D_2031_-_97.pdf

Designation:D 2031 97Standard Test Method forReducing Substances in Refined Pyridine1This standard is issued under the fixed designation D 2031;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 This test method covers the qualitative determination ofreducing substances in refined pyridine.1.2 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.For specific hazardstatements,see Section 6.2.Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water2D 3437 Practice for Sampling and Handling Liquid CyclicProducts32.2Other Document:4OSHA Regulations,29 CFR,paragraphs 1910.1000 and1910.1200.3.Summary of Test Method3.1 Specified volumes of pyridine and potassium perman-ganate are mixed,allowed to stand for 30 min at roomtemperature,and the color of the solution noted.4.Significance and Use4.1 This test method gives a qualitative means of detectionof reducing substances in pyridine.5.Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless 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.5Other 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.5.2 Purity of WaterUnless otherwise indicated,referencesto water shall be understood to mean reagent water conformingto Types I to IV of Specification D 1193.5.3 Potassium Permanganate Solution(3.2 g/L)Dissolve3.2 g of potassium permanganate(KMnO4)in water and diluteto 1 L in a volumetric flask.Standardization of the solution isnot required.Store the permanganate solution in a brown bottleand prepare fresh every 30 days.5.4 Hydrochloric Acid,concentrated(HCl,sp gr 1.19).NOTE1Clean all equipment used to store and handle the permanga-nate solution with concentrated hydrochloric acid(HCl,sp gr 1.19)andrinse thoroughly with water.Continuous use of such equipment withoutcleaning results in a deposition of manganese dioxide(MnO2)whichcatalyzes reduction of the permanganate.6.Hazards6.1 Consult current OSHA regulations,suppliers MaterialSafety Data Sheets,and local regulations for all materials usedin this test method.7.Sampling and Handling7.1 Sample the material in accordance with practice D3437.8.Procedure8.1 Pipet 5 mL of pyridine specimen and 0.5 mL of KMnO4solution into a 25 by 150-mm test tube.Mix thoroughly byshaking,stopper,and let stand for 30 min at room temperature.8.2 Note the color of the specimen solution.If a brown coloror precipitate interferes,the solution should be centrifuged orfiltered through a sintered glass filter before observing the colorof the solution.9.Report9.1 If the specimen solution retains any permanganate(purple-pink)color,report the specimen“passes.”9.2 If all of the permanganate color has been discharged1This test method is under the jurisdiction of ASTM Committee D-16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.0D on Organic Nitrogen Compounds.Current edition approved Dec.10,1997.Published September 1998.Originallypublished as D 2031 64 T.Last previous edition D 2031 93.2Annual Book of ASTM Standards,Vol 11.01.3Annual Book of ASTM Standards,Vol 06.04.4Available from Superintendent of Documents,U.S.Government PrintingOffice,Washington,DC 20402.5Reagent 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.1AMERICAN SOCIETY FOR TESTING AND MATERIALS100 Barr Harbor Dr.,West Conshohocken,PA 19428Reprinted from the Annual Book of ASTM Standards.Copyright ASTMfrom the specimen solution,report the specimen“fails.”10.Precision and Bias10.1 This test method for determining reducing substancesin pyridine has no precision nor bias because the value ofreducing substances in pyridine is defined only in terms of thistest method.11.Keywords11.1 permanganate;pyridine;reducing substancesThe American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connectionwith any item mentioned in this standard.Users of this standard are expressly advised that determination of the