ASTM_D_7419_-_18.pdf

Designation:D741918Standard Test Method forDetermination of Total Aromatics and Total Saturates inLube Basestocks by High Performance LiquidChromatography(HPLC)with Refractive Index Detection1This standard is issued under the fixed designation D7419;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.1.Scope*1.1 This test method covers the determination of totalaromatics and total saturates in additive-free lube basestocksusing high performance liquid chromatography(HPLC)withrefractive index(RI)detection.This test method is applicableto samples containing total saturates in the concentration rangeof 74.9%to 100.0%by mass and aromatics in the concentra-tion range of 0.0%to 25.1%by mass.The precision isexpressed in terms of the total saturates.1.1.1 Polar compounds,if present,are combined with thetotal aromatics.Precision was determined for basestocks withpolars content 1.0%by mass.1.2 This test method includes a relative bias section for totalsaturates in basestocks based on a Practice D6708 accuracyassessment between Test Method D7419 and Test MethodD2007.The derived correlation equation is only applicable forbasestocks in the total saturates concentration range from75.0%to 100.0%by mass as measured by Test MethodD7419.1.2.1 The applicable range for total saturates by TestMethod D2007 is from 71.0%to 99.0%by mass as reportedby Test Method D2007.1.3 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 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 the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D2007 Test Method for Characteristic Groups in RubberExtender and Processing Oils and Other Petroleum-Derived Oils by the Clay-Gel Absorption Chromato-graphic MethodD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD6299 Practice for Applying Statistical Quality Assuranceand Control Charting Techniques to Evaluate AnalyticalMeasurement System PerformanceD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6708 Practice for Statistical Assessment and Improvementof Expected Agreement Between Two Test Methods thatPurport to Measure the Same Property of a Material3.Terminology3.1 Definitions:3.1.1 aromatics,ninhighperformanceliquidchromatography,aromatic hydrocarbon components,minuspolar material,that have a longer retention time than saturateson the specified polar columns,but can be removed as a singlepeak by backflushing the columns with heptane.3.1.1.1 DiscussionGenerally,aromatic hydrocarbons con-tain one to four rings.3.1.2 backflush,velution of the HPLC mobile phase in thebackward or reverse direction from the silica gel columntowards the cyano column.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0C on Liquid Chromatography.Current edition approved July 1,2018.Published November 2018.Originallyapproved in 2007.Last previous edition approved in 2013 as D7419 13.DOI:10.1520/D7419-18.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,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 3.1.2.1 DiscussionIn this test method,it is used to elutethe total aromatics plus polars as one sharp component.3.1.3 foreflush,velution of HPLC mobile phase in theforward direction.3.1.3.1 DiscussionIn this test method,the sample entersthe cyano column first followed by elution through the silicagel