1、Designation:D184007(Reapproved 2013)Standard Test Method forNaphthalene Hydrocarbons in Aviation Turbine Fuels byUltraviolet Spectrophotometry1This standard is issued under the fixed designation D1840;the number immediately following the designation indicates the year oforiginal adoption or,in the c
2、ase 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 Department of Defense.1.Scope1.1 This test meth
3、od covers the determination,by ultravioletspectrophotometry,of the total concentration of naphthalene,acenaphthene,and alkylated derivatives of these hydrocarbonsin jet fuels.This test method is designed to analyze fuelscontaining not more than 5%of such components and havingend points below 315C(60
4、0F);however,the range ofconcentrations used in the interlaboratory test programs whichestablished the precision statements for this test method were0.03 to 4.25 volume%for ProcedureA,and 0.08 to 5.6 volume%for Procedure B.This test method determines the maximumamount of naphthalenes that could be pr
5、esent.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 ap
6、pro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specificwarning statements,see 8.1 and 8.2.2.Referenced Documents2.1 ASTM Standards:2E131 Terminology Relating to Molecular SpectroscopyE169 Practices for General Techniques of Ultravio
7、let-VisibleQuantitative AnalysisE275 Practice for Describing and Measuring Performance ofUltraviolet and Visible Spectrophotometers3.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
8、particular significance are the follow-ing:3.1.2 radiant energy,nenergy transmitted as electromag-netic waves.3.1.3 radiant power,P,nrate at which energy is trans-ported in a beam of radiant energy.3.2 Definitions of Terms Specific to This Standard:3.2.1 absorbance,A,nthe molecular property of a sub
9、-stance that determines its ability to take up radiant power,expressed byA 5 log101/T!5 2log10T(1)where:T=transmittance as defined in 3.2.5.3.2.1.1 DiscussionIt may be necessary to correct theobserved transmittance(indicated by the spectrophotometer)by compensating for reflectance losses,solvent abs
10、orptionlosses,or refraction effects.3.2.2 absorptivity,a,nthe specific property of a substanceto absorb radiant power per unit sample concentration and pathlength,expressed bya 5 A/bc(2)where:A=absorbance defined in 3.2.1,b=sample cell path length,andc=quantity of absorbing substance contained in a
11、unitvolume of solvent.3.2.2.1 DiscussionQuantitative ultraviolet analyses arebased upon the absorption law,known as Beers law.The lawstates that the absorbance of a homogeneous sample containingan absorbing substance is directly proportional to the concen-tration of the absorbing substance at a sing
12、le wavelength,expressed byA 5 abc(3)where:1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and is the direct responsibility ofSubcommittee D02.04.0F on Absorption Spectroscopic Methods.Current edition approved Oct.1,2013.Published Oct
13、ober 2013.Originallyapproved in 1961.Last previous edition approved in 2007 as D1840 07.DOI:10.1520/D1840-07R13.2For 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 stand
14、ards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 A=absorbance as defined in 3.2.1,a=absorptivity as defined in 3.2.2,b=sample cell path length,andc=quantity of absorbing substance contained in
15、a unitvolume of solvent.3.2.3 concentration,c,nthe quantity of naphthalene hy-drocarbons in grams per litre of isooctane.3.2.4 sample cell path length,b,nthe distance,incentimetres,measured in the direction of propagation of thebeam of radiant energy,between the surfaces of the specimenon which the
16、radiant energy is incident and the surface of thespecimen from which it is emergent.3.2.4.1 DiscussionThis distance does not include thethickness of the cell in which the specimen is contained.3.2.5 transmittance,T,nthe molecular property of a sub-stance that determines its transportability of radiant powerexpressed byT 5 P/Po(4)where:P=radiant power passing through the sample,andPo=radiant power incident upon the sample.4.Summary of Test Method4.1 The total concentration of naphthalenes in jet
