1、Designation:D312008(Reapproved 2014)Standard Test Method forTrace Quantities of Sulfur in Light Liquid PetroleumHydrocarbons by Oxidative Microcoulometry1This standard is issued under the fixed designation D3120;the number immediately following the designation indicates the year oforiginal adoption
2、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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1
3、 This test method covers the determination of sulfurconcentration in the range from 3.0 to 1000 mg kg in lightliquid hydrocarbons and fuels with oxygenates boiling in therange from 26 to 274C(80 to 525F).NOTE1Preliminary data has shown that this test method is alsoapplicable to the determination of
4、sulfur in denatured fuel ethanol(Specification D4806),automotive spark ignition engine fuel(Specifica-tion D4814),Ed75Ed85(Specification D5798)or gasoline-oxygenatefuel blends with greater than 10%ethanol.However,the precision forthese materials has not been determined.Subcommittee D02.03 isundertak
5、ing activities to obtain precision statements for these materials.1.2 Other materials falling within the distillation rangespecified in 1.1,but having sulfur concentrations above 1000mg/kg,may be tested using appropriate dilutions to bring themwithin the specified limit.In addition,sample types that
6、 may beoutside the specified distillation range,such as diesels andbiodiesels,may be analyzed by this test method.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.The preferred units are milligrams per kilogram(mg/kg).1.4 This
7、 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 hazardstateme
8、nts,see Sections 7 9.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1298 Test Method for Density,Relative Density,or APIGravity of Crude Petroleum and Liquid Petroleum Prod-ucts by Hydrometer MethodD4052 Test Method for Density,Relative Density,and APIGravity of Liqu
9、ids by Digital Density MeterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4806 Specification for Denatured Fuel Ethanol for Blend-ing with Gasolines for Use as Automotive Spark-IgnitionEngine FuelD4814 Sp
10、ecification for Automotive Spark-Ignition EngineFuelD5798 Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition EnginesD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System Performance2.2OSHA Regu
11、lations:OSHA Regulations 29 CFR,paragraphs 1910.1000 and1910.120033.Summary of Test Method3.1 A liquid sample is introduced into a pyrolysis tubemaintained at a temperature between 900 to 1200C,having aflowing stream of gas containing 50 to 80%oxygen and 20 to50%inert gas(for example,argon,helium,an
12、d so forth).Oxidative pyrolysis converts the sulfur to sulfur dioxide,whichthen flows into a titration cell where it reacts with triiodide ionpresent in the electrolyte.The triiodide ion consumed iscoulometrically replaced and the total current(I t)required toreplace it is a measure of the sulfur pr
13、esent in the sample.3.2 The reaction occurring in the titration cell as sulfurdioxide enters is:I321SO21H2OSO313I212H1(1)1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.03 on Elemen
14、tal Analysis.Current edition approved May 1,2014.Published July 2014.Originally approvedin 1972.Last previous edition approved in 2008 as D3120 08.DOI:10.1520/D3120-08R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual
15、Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from U.S.Government Printing Office,Superintendent ofDocuments,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401.*A Summary of Changes section appears at the end of this standardC
16、opyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 The triiodide ion consumed in the above reaction is gener-ated coulometrically thus:3I2I3212e2(2)3.3 These microequivalents of triiodide ion(iodine)areequal to the number of microequivalents of titratable SO2ionentering the titration cell.4.Significance and Use4.1 This test method is used to determine the concentrationof sulfur in light liquid hydrocarbons,gasoline,and diesels andtheir ad
