ASTM_D_7373_-_12.pdf

Designation:D737312Standard Test Method forPredicting Biodegradability of Lubricants Using a Bio-kinetic Model1This standard is issued under the fixed designation D7373;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 a procedure for predictingbiodegradability of lubricants using a bio-kinetic model.1.2 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.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 applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D2549 Test Method for Separation of Representative Aro-matics and Nonaromatics Fractions of High-Boiling Oilsby Elution ChromatographyD5864 Test Method for Determining Aerobic Aquatic Bio-degradation of Lubricants or Their ComponentsD6300 Practice for Determination of Precision and BiasData for Use in Test Methods for Petroleum Products andLubricantsD6731 Test Method for Determining the Aerobic,AquaticBiodegradability of Lubricants or Lubricant Componentsin a Closed Respirometer3.Terminology3.1 Definitions:3.1.1 aromatics fraction,nportion of the sample desorbedwith the polar eluants.The aromatics fraction is divided intononpolar and polar based.They may contain aromatics,con-densed naphthenic-aromatics,aromatic olefins,and com-pounds containing sulfur,nitrogen,and oxygen atoms.3.1.2 bio-kinetic model,nmodel that can predict the bio-degradability of a lubricant.3.1.3 biodegradability,nability of a substance to be bro-ken down into simpler substances by bacteria.3.1.4 effective composition to biodegradation(ECB),ncomponent of material that can be biodegradable by bacte-ria.3.1.4.1 DiscussionThe term ECB is a part of bio-kineticmodel is sum of non-aromatic components in a lubricant.3.1.5 nonaromatics fraction,nportion of the sampleeluted with n-pentane.The nonaromatics fraction is a mixtureof paraffinic and naphthenic hydrocarbons if sample is astraight-run material.If the sample is a cracked stock,thenonaromatics fraction will also contain aliphatic and cyclicolefins.4.Summary of Test Method4.1 A weighed amount of sample is charged to the top of aglass chromatographic column packed with activated bauxiteand silica gel.To elute the nonaromatics,n-pentane is added tothe column.When all of the nonaromatics are eluted,non-polararomatics fraction is eluted by additions of an equal mixture oftoluene and n-pentane.The ester fraction is eluted by additionsof diethyl ether.Then,the polar-aromatics is eluted by chloro-form and ethyl alcohol.4.2 The solvents are completely removed by evaporation,and the residues are weighed and calculated as thenonaromatics,nonpolar aromatics,ester fractions,and polararomatics of the sample.4.3 ECB is calculated based on the amount of nonaromaticsand ester fractions with their material ECB coefficients.Then,the biodegradability of a lubricant is calculated using thebio-kinetic model.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.12 on Environmental Standards for Lubricants.Current edition approved June 1,2012.Published October 2012.Originallyapproved in 2007.Last previous edition approved in 2007 as D7373071.DOI:10.1520/D7373-12.2For 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 States1 5.Significance and Use5.1 This procedure is able to predict the biodegradability oflubricants within a day without dealing with microorganisms.3Excellent correlation is established between the test results andthe conventional biodegradation tests(see Test Method D5864and Test Method D6731).6.Apparatus6.1 Chromatographic Columnsas shown in Fig.1(seeTest Method D2549).6.2 Beakers(100,250,and 600-mL)inverted-rim type.6.3 Steam Bath.6.4 Electric Vibratorfor packing column.6.5 Weighing Bottles or Erlenmeyer Flasks25 and 50 mL.6.6 Graduated Cylinders50 mL,100 mL,and 250 mL.7.Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in this test.Unless otherwise indicated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such