ASTM_D_6304_-_16e1.pdf

Designation:D6304161Standard Test Method forDetermination of Water in Petroleum Products,LubricatingOils,and Additives by Coulometric Karl Fischer Titration1This standard is issued under the fixed designation D6304;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()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.1NOTEReference to a Summary of Changes was removed editorially in September 2016.1.Scope1.1 This test method covers the direct determination ofwater in the range of 10 mg kg to 25 000 mg kg entrainedwater in petroleum products and hydrocarbons using auto-mated instrumentation.This test method also covers theindirect analysis of water thermally removed from samples andswept with dry inert gas into the Karl Fischer titration cell.Mercaptan,sulfide(Sor H2S),sulfur,and other compoundsare known to interfere with this test method(see Section 5).1.2 This test method is intended for use with commerciallyavailable coulometric Karl Fischer reagents and for the deter-mination of water in additives,lube oils,base oils,automatictransmission fluids,hydrocarbon solvents,and other petroleumproducts.By proper choice of the sample size,this test methodmay be used for the determination of water from mg/kg topercent level concentrations.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 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: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 Liquids by Digital Density MeterD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD5854 Practice for Mixing and Handling of Liquid Samplesof Petroleum and Petroleum ProductsE203 Test Method for Water Using Volumetric Karl FischerTitration3.Summary of Test Method3.1 An aliquot is injected into the titration vessel of acoulometric Karl Fischer apparatus in which iodine for the KarlFisher reaction is generated coulometrically at the anode.When all of the water has been titrated,excess iodine isdetected by an electrometric end point detector and the titrationis terminated.Based on the stoichiometry of the reaction,1 molof iodine reacts with 1 mol of water;thus,the quantity of wateris proportional to the total integrated current according toFaradays Law.3.2 The sample injection can be done either by mass orvolume.3.3 The viscous samples can be analyzed by using a watervaporizer accessory that heats the sample in the evaporationchamber,and the vaporized water is carried into the KarlFischer titration cell by a dry inert carrier gas.4.Significance and Use4.1 A knowledge of the water content of lubricating oils,additives,andsimilarproductsisimportantinthemanufacturing,purchase,sale,or transfer of such petroleumproducts to help in predicting their quality and performancecharacteristics.4.2 For lubricating oils,the presence of moisture could leadto premature corrosion and wear,an increase in the debris load1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.06 on Analysis of Liquid Fuels and Lubricants.Current edition approved July 1,2016.Published July 2016.Originally approvedin 1998.Last previous edition approved in 2007 as D6304 07,which waswithdrawn in April 2016 and reinstated in July 2016.DOI:10.1520/D6304-16.2For 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 standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 resulting in diminished lubrication and premature plugging offilters,an impedance in the effect of additives,and undesirablesupport of deleterious bacterial growth.5.Interferences5.1 A number of substances and classes of compoundsassociated with condensation or oxidation-reduction reactionsinterferes in the determination of water by Karl Fischertitration.In petroleum products,the most common interfer-ences are mercaptans and sulfides.At levels of less than500 mgkg as sulfur,the interference from these comp