ASTM_D_984_-_97_2002.pdf

Designation:D 984 97(Reapproved 2002)Technical Association of Pulp and Paper IndustryStandard Method T 406 Su-72An American National StandardStandard Test Methods forReducible Sulfur in Paper1This standard is issued under the fixed designation D 984;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 reduciblesulfur in paper and paperboard within the context of the givendefinitions.1.1.1 Method BThe semiquantitative method indicates thegeneral level of reducible sulfur with limited accuracy.1.1.2 Method AThe quantitative method gives a measureof the reducible sulfur with much greater accuracy.2,31.2 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.2.Referenced Documents2.1 ASTM Standards:D 585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard,and Related Product4D 644 Test Method for Moisture Content of Paper andPaperboard by Oven Drying4D 1968 Terminology Relating to Paper and Paper Products4D 2043 Test Method for Silver Tarnishing by Paper43.Terminology3.1 DefinitionsDefinitions shall be in accordance withTerminology D 1968 and the Dictionary of Paper.54.Summary of Test Methods4.1 Method B,semiquantitative method,involves the reduc-tion of various forms of sulfur to hydrogen sulfide and thedevelopment of a dark spot of lead sulfide on the filter paperimpregnated with lead acetate.The intensity of the spot iscompared with spots developed from standards and is propor-tional to the concentration.No colorimeter or spectrophotom-eter is needed for this method.4.2 Method A,the quantitative method,uses the identicalreduction system to generate hydrogen sulfide,but the sulfideis precipitated by alkaline cadmium sulfate and then convertedtomethylenebluebyreactionwithacidicp-aminodimethylaniline in the presence of ferric chloride.Themethylene blue is measured spectrophotometrically and theintensity is compared with standards prepared in similarmanner.5.Significance and Use5.1 The test methods outlined are not necessarily a measureof how much a given test material will tarnish polished metals.When tested by these methods,paper that has less than0.0008%reducible sulfur,may be assumed to be nontarnishingas far as sulfur is concerned,but if more than 0.0008%,thisdoes not necessarily mean that tarnishing will occur,becausesulfur compounds which may not cause staining are reduced bythe treatment with the subsequent evolution of hydrogensulfide.If more than 0.0008%reducible sulfur is found,or ifthe effect of that or other materials causing stains on silver isdesired,the paper should be subjected to an acceleratedtarnishing test(see Test Method D 2043).NOTE1If the pH of the paper is low(for example,4.0 to 4.5(coldextraction)as little as 0.0002%of reducible sulfur may cause tarnishingof imitation gold bronze prints;whereas,if the pH were higher,(forexample,on brush-coated art paper)a much higher quantity of sulfurmight be tolerated.5.2 The test methods described do not give the total sulfurcontent,nor the total reducible sulfur content,nor are theyintended to.They are limited to the reducible sulfur contentdetermined under the conditions of the test(that is,a fairlymild reduction system).35.2.1 Those forms of sulfur believed to be“reducible”underthe test conditions are(1)sulfide(released by the acid,notactually reduced),(2)elemental sulfur,(3)thiosulfate,(4)otherpolythionates or polysulfides,and(5)perhaps sulfite.Sulfate isexcluded.1These test methods are under the jurisdiction of ASTM Committee D06 onPaper and Paper Products and are the direct responsibility of Subcommittee D06.92on Test Methods.Current edition approved Dec.10,1997.Published November 1998.Originallypublished as D 984 48 T.Last previous edition D 984 92(1996).2Sobolev,I.,Bhargava,R.,Gosuntov,N.,and Russell,R.,Tappi 39(9):628(1956).3Chazin,J.D.,“Colorimetric Determination of Reducible Sulfur in Paper andPaperboard,”Tappi,Journal of the Technical Association of the Pulp and PaperIndustry,TAPPI,Vol 53,No.8,1970,p.1514.4Annual Book of ASTM Standards,Vol 15.09.5Available from the Technical Association of the Pulp and Paper Industry,P.O.Box 105113,Atlanta,GA 30348.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.6.Sampling6.1 Obtain the sample in accordance with Practice D 585.6.2 A minimum of 6 g of sample is required to providetriplicate test specimens.6.3 Do not touch the test area of sample or test specimenswith the fingers;handle with clean forceps onl