ASTM_D_6313_-_99.pdf

Designation:D 6313 99Test Method forTotal Sulfur in Aromatic Compounds by Hydrogenolysis andSulfur Specific Difference Photometry1This standard is issued under the fixed designation D 6313;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 determination of sulfur inaromatic hydrocarbons,their derivatives and related chemicalshaving typical sulfur concentrations from 0.005 to 10 mg/kg.1.2 This test method may be extended to higher concentra-tions by dilution.1.3 This test method is applicable to aromatic hydrocarbonssuch as benzene,toluene,cumene,p-xylene,o-xylene,cyclo-hexane,phenol,cresols,xylenols,and other aromatic oroxygenated aromatic compounds.1.4 The following applies to all specified limits in this testmethod:for purposes of determining conformance with thisstandard,an observed value or a calculated value shall berounded off to the nearest unit in the last right-hand digit usedfor expressing the specification limit in accordance with therounding-off method of Practice E 29.1.5 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 precau-tionary statements are given in 7.5,7.6,8,11.4.2.Referenced Documents2.1 ASTM Standards:D 1193 Specification for Reagent Water2D 3437 Practice for Sampling and Handling Liquid CyclicProducts3D 3852 Practice for Sampling and Handling Phenol andCresylic Acid3D 4052 Test Method for Density and Relative Density ofLiquids for Digital Density Meter4D 4790 Terminology of Aromatic Hydrocarbons and Re-lated Chemicals3E 29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications52.2Other Documents:OSHA Regulations,29 CFR,paragraphs 1910.1000 and1910.1200063.Terminology3.1 Definitions:3.1.1 difference photometry,nan analytical method wherea photometric property of a colorimetric reactant(such asreflectivity)is first measured as a baseline reading,the reactantexposed to the material in question,then a second readingtaken.3.1.1.1 DiscussionThe difference between the post expo-sure reading and the baseline reading constitute the measure-ment of the reaction between the material in question and thereactant,that is,if the reactant changes its photometric propertyproportionally to the concentration of the material in question,the method could be used to measure concentration.3.1.2 oxyhydropyrolysis,vThe act of first burning a ma-terial within an inner chamber in a pyrolysis furnace to changethat material to combustion products,and then to release thoseproducts into a hydrogen rich atmosphere to then reduce thosecombustion products.3.2 See Terminology D 4790 for definitions of other termsused in this test method.4.Summary of Test Method4.1 Reductive ConfigurationA specific amount of sampleis injected at a uniform rate into an air stream and introducedinto a sample dispersing mechanism where the liquid sample isevaporated and thoroughly mixed with the hydrogen.Thismixture is then introduced into a pyrolysis furnace.Within thisapparatus the sample is pyrolyzed at temperatures of 1200 to1300C and in the presence of excess hydrogen.The sulfurcompounds are broken down and reduced to H2S.Analysis isby difference photometry of the colorimetric reaction of H2Swith lead acetate.4.2 OxyhydroPyrolysis ConfigurationA specific amountof sample is injected at a uniform rate into an air stream and1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D016.04 on Instrumental Analysis.Current edition approved April 10,1999.Published June 1999.Originallypublished as D 6313 98.Last previous edition D 6313 98.2Annual Book of ASTM Standards,Vol 11.01.3Annual Book of ASTM Standards,Vol 06.04.4Annual Book of ASTM Standards,Vol 05.02.5Annual Book of ASTM Standards,Vol 14.02.6Available from Superintendent of Documents,U.S.Government Printing office,Washington,DC 20402.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.introduced into a sample dispersing mechanism where theliquid sample is evaporated and thoroughly mixed with the air.This mixture is then introduced into a pyrolysis furnace.Thesample flows through an inner tube within the furnace where itcombusts with the oxygen in the air carrier.SO2and SO3areformed from the sulfur compounds in the sample.The samplethen leaves the inner tube within the pyrolyzer and is mixedwith hydrogen within the main reaction tube and is pyrolyzedat temperatures of 1200 t