ASTM_D_7922_-_14.pdf

Designation:D792214Standard Test Method forDetermination of Glycol for In-Service Engine Oils by GasChromatography1This standard is issued under the fixed designation D7922;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.Scope1.1 This test method covers the determination of glycolbased antifreeze for in-service engine oil by derivativeheadspace/gas chromatography.1.2 Sample is derivatized in-situ directly in a headspacesampling vial prior to vapor phase extraction and injection intoa gas chromatograph.1.3 The chemistry of the derivatization is unique to thedetection of the molecules of ethylene glycol and 1,2-propylene glycol.1,3-propylene glycol could also be detectedbut is not used in any known anti-freeze at this time.Othercoolant analyses are beyond the scope of this test method.1.4 The derivatization process does not affect glycol break-down products such as glycolate and formate and hence thepresence of these compounds in the oil will not be quantified.1.5 The test method concentration range is from 50 g/g to1000 gg.Lower levels are possible by method modifications.Higher levels are possible through sample dilution.1.6 UnitsThe values stated in SI units are to be regardedas standard.No other units of measurement are included in thisstandard.1.7 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:2D4291 Test Method for Trace Ethylene Glycol in UsedEngine OilE355 Practice for Gas Chromatography Terms and Relation-shipsE594 Practice for Testing Flame Ionization Detectors Usedin Gas or Supercritical Fluid ChromatographyE1510 Practice for Installing Fused Silica Open TubularCapillary Columns in Gas Chromatographs3.Terminology3.1 Definitions:3.1.1 This test method makes reference to common gaschromatographic procedures,terms,and relationships.Detaileddefinitions of these can be found in Practices E355 and E594.3.1.2 antifreeze,nantifreeze is typically a dilution ofethylene glycol and possibly other glycols,and additives,inwater to act as a machine coolant.1,2-propanediol is found insome antifreeze formulations.3.1.3 derivitization reagent,na saturated solution of phe-nylboronic acid(PBA)in solvent.Acetone and 2,2-dimethoxypropane have been used successfully.Gentle warm-ing at 50 C will hasten dissolution.Solution is stable for threemonths at room temperature if kept away from moisture.3.1.4 glycol,nthe amount,expressed as a percentage,ofglycol found in the in-service lubricating oil.The mostcommon glycol formulated into antifreeze is ethylene glycol(CAS#107-21-1)with some antifreeze also containing 1,2-propanediol also known as propylene glycol(CAS#57-55-6).Another glycol such as 1,3-propanediol(CAS#504-63-2)isdetected by this test method but is not commonly used inantifreeze formulations.3.1.5 glycols,nthe summed amount of individual glycolsfound in the in-service lubricating oil.3.1.6 in-service oil,nlubricating oil that is present in amachine that has been at operating temperature for at least 1 h.4.Summary of Test Method4.1 A representative aliquot of in-service engine oil isintroduced into a headspace sampling vial along with aderivatizing agent.The headspace vial is heated to volatilizethe derivatized glycol into the vapor phase.Using a smallaliquot of sample and derivatization reagent approaches a totalvaporization technique to minimize partition coefficient differ-ences in in-service oil samples.A representative aliquot of the1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0L on Gas Chromatography Methods.Current edition approved July 15,2014.Published September 2014.DOI:10.1520/D7922-14.2For 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 vapor sample is introduced to the gas chromatograph.Carriergas transports the vaporized aliquot through the dimethylpolysiloxane bonded phase capillary column where the glycolsare separated by the chromatographic process.The detectorsignal is processed by an electronic data acquisition system.The components are identified by comparing their retentiontimes to ones identified by analyzing standards under identicalconditions.The concentrations of all compone