ASTM_D_4053_-_04_2009.pdf

Designation:D405304(Reapproved 2009)Standard Test Method forBenzene in Motor and Aviation Gasoline by InfraredSpectroscopy1This standard is issued under the fixed designation D4053;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 the percentbenzene in full-range gasoline.It is applicable to concentra-tions from 0.1%to 5 volume%.1.2 This test method has not been validated for gasolinescontaining oxygenates.Certain oxygenates interfere with themeasurement described in this test method.Test MethodD6277 is recommended for gasolines containing oxygenates.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.For specificwarning statements,see Section 8 and 9.1.2.Referenced Documents2.1 ASTM Standards:2D4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD6277 Test Method for Determination of Benzene in Spark-Ignition Engine Fuels Using Mid Infrared SpectroscopyE131 Terminology Relating to Molecular SpectroscopyE932 Practice for Describing and Measuring Performance ofDispersive Infrared SpectrometersE1421 Practice for Describing and Measuring Performanceof Fourier Transform Mid-Infrared(FT-MIR)Spectrom-eters:Level Zero and Level One Tests3.Terminology3.1 Definitions:3.1.1 Definitions of terms and symbols relating to absorp-tion spectroscopy in this test method shall conform to Termi-nology E131.Terms of particular significance are the follow-ing:3.1.2 absorbance,A,nthe molecular property of a sub-stance that determines its ability to take up radiant power,expressed by:A 5 log101/T!5 2log10T(1)where:T=the transmittance as defined in 3.1.5.3.1.3 radiant energy,nenergy transmitted as electromag-netic waves.3.1.4 radiant power,P,nthe rate at which energy istransported in a beam of radiant energy.3.1.5 transmittance,T,nthe molecular property of a sub-stance that determines its transportability of radiant power,expressed by:T 5 P/Po(2)where:P=the radiant power passing through the sample,andPo=the radiant power incident upon the sample.4.Summary of Test Method4.1 A sample of gasoline is examined by infrared spectros-copy and,following a correction for interference,comparedwith calibration blends of known benzene concentration.Fromthis comparison the amount of benzene in the gasoline isdetermined.5.Significance and Use5.1 Benzene is classed as a toxic material.A knowledge ofthe concentration of this compound may be an aid in evaluatingthe possible health hazard to persons handling and using thegasoline.This test method is not intended to evaluate suchhazards.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04.0F on Absorption Spectroscopic Methods.Current edition approved April 15,2009.Published July 2009.Originallyapproved in 1981.Last previous edition approved in 2004 as D4053 04.DOI:10.1520/D4053-04R09.2For 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 StatesNOTICE:This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International(www.astm.org)for the latest information16.Interferences6.1 Toluene and heavier aromatic compounds have someinterference in this test method.In order to minimize the effectof such interference,this test method includes a procedure thatcorrects for the error caused by the presence of toluene.Errordue to other sources of interference may be partially compen-sated for by calibrating with gasoline stocks containing little orno benzene but which otherwise are similar in aromatic contentto the samples to be analyzed.7.Apparatus7.1 Absorption Cell,sealed.Windows of potassium bromideor other material having sufficient transmittance out to 440cm1(22.73 m),in a cell having TFE-fluorocarbon plugs andnominal path length of 0.025 mm known to three significantnumbers.7.2 Clear Reference BlockA block made from the samematerial as cell windows for use in the reference beam path ofa double-beam spectrometer.7.3 Infrared Spectrometer,double-beam or single-beam,suitable for recording accurate measurements between 690cm1(14.49 m)and