1、Designation:D495212(Reapproved 2017)Standard Test Method forQualitative Analysis for Active Sulfur Species in Fuels andSolvents(Doctor Test)1This standard is issued under the fixed designation D4952;the number immediately following the designation indicates the year oforiginal adoption or,in the cas
2、e 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 This test me
3、thod covers and is intended primarily for thedetection of mercaptans in motor fuel,kerosine,and similarpetroleum products.This method may also provide informationon hydrogen sulfide and elemental sulfur that may be present inthese sample types.1.2 The values stated in SI units are to be regarded ass
4、tandard.No other units of measurement are included in thisstandard.1.3 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 appli
5、ca-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by t
6、he World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD3227 Test Method for(Thiol Mercaptan)Sulfur inGasoline,Kerosine,Aviation Turbine,and Distillate Fuels(Potentiometric Method)2.2 Energy Institute Standa
7、rds:3IP30 Detection of Mercaptans,Hydrogen Sulfide,ElementalSulfur,and Peroxides Doctor Test Method3.Summary of Test Method3.1 The sample is shaken with sodium plumbite solution,asmall quantity of powdered sulfur added,and the mixtureshaken again.The presence of mercaptans or hydrogen sulfideor both
8、 is indicated by discoloration of the sulfur floating at theoil-water interface or by discoloration of either of the phases.4.Significance and Use4.1 Sulfur present as mercaptans or as hydrogen sulfide indistillate fuels and solvents can attack many metallic andnon-metallic materials in fuel and oth
9、er distribution systems.Anegative result in the doctor test ensures that the concentrationof these compounds is insufficient to cause such problems innormal use.5.Interferences5.1 This test cannot be used if there are more than traceamounts of peroxides in the test sample.Peroxides can give afalse p
10、ositive results where mercaptans are at low level or noteven present.45.2 To check if peroxides are present in sufficient concen-tration to invalidate the test,shake 10 mL 6 0.5 mL of a freshportion of the sample with approximately 2 mL of the potas-sium iodide solution,add two drops of the acetic a
11、cid solution,and two drops of the starch solution.If the aqueous layer turnsa blue color,this confirms the presence of peroxides insufficient quantity to invalidate the test,and the test on thissample should be discontinued.Proceed in accordance with5.4.5.3 Alternatively,one may choose to perform a
12、preliminaryDoctor Test.If a brown precipitate slowly forms,peroxide isprobably present.Proceed in accordance with 5.2 to confirmpresence of peroxides at sufficient quantity to invalidate thetest.5.4 If interference from peroxides is confirmed,proceed tore-sample and retest.Ensure that sampling and h
13、andlingprocedures for the new sample prevent UV light exposures as1This 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 Elemental Analysis.Current edition approved May 1,2017.Publis
14、hed June 2017.Originallyapproved in 1989.Last previous edition approved in 2012 as D4952 12.DOI:10.1520/D4952-12R17.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the s
15、tandards Document Summary page onthe ASTM website.3Available from Energy Institute,61 New Cavendish St.,London,WIG 7AR,U.K.,http:/www.energyinst.org.4Brooks,B.T.,“Sodium Plumbite or Doctor Test of Gasolines,”Industrial andEngineering Chemistry,Vol 16,No.6,June 1924,p.588.Copyright ASTM International
16、,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 prescribed in 7.1.None of the normal refinery units or blendingprocesses producing spark ignition motor