1、Designation:D238483(Reapproved 2014)Standard Test Methods forTraces of Volatile Chlorides in Butane-Butene Mixtures1This standard is issued under the fixed designation D2384;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of
2、 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 These test methods cover the determination of the totalvolatile organic chlorides in concentrations from 10 to100 ppm in b
3、utane-butene mixtures.The amperometric finishis not directly applicable in the presence of other substancesthat combine with silver ion or oxidize chloride ion in diluteacid solution.Bromides,sulfides,ammonia,tobacco smoke,and more than 25 g of hydrogen peroxide in the test solutioninterfere in the
4、spectrophotometric procedure.1.2 Dissolved sodium chloride is not quantitatively deter-mined using these test methods.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 thesaf
5、ety 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.Specific warningstatements are given in Sections 5,8,11,14,19,and AnnexA1.2.R
6、eferenced Documents2.1 ASTM Standards:2D329 Specification for AcetoneD1266 Test Method for Sulfur in Petroleum Products(LampMethod)3.Summary of Test Methods3.1 Combination Test MethodsEither the lamp or oxy-hydrogen test method may be used for combustion.NOTE1Lamp combustion is readily applicable to
7、 multiple testing.Although an oxy-hydrogen burner does not lend itself to multiple testing,it affords much more rapid analysis for a single sample than does the lampcombustion.3.1.1 Lamp CombustionThe sample is burned in an atmo-sphere of carbon dioxide and oxygen or in purified air;thehalogen-conta
8、ining combustion products are absorbed in dilutesodium carbonate solution.3.1.2 Oxy-Hydrogen CombustionThe sample is burned inan oxy-hydrogen atomizer burner,and the combustion productsare absorbed in a dilute solution of sodium carbonate.3.2 FinishesEither the amperometric titration or spectro-phot
9、ometric finish may be used for the chloride ion determi-nation.3.2.1 Amperometric TitrationThe chloride ion in aqueoussolution is titrated amperometrically with standard silver ni-trate solution,using a saturated calomel electrode as referenceelectrode.The diffusion currents are plotted against the
10、corre-sponding volumes of silver nitrate solution used;the end pointis taken as the intersection of the two straight-line portions ofthe curve.3.2.2 Spectrophotometric FinishChloride ion in the ab-sorber solution is determined by reaction with mercuric thio-cyanate to release thiocyanate,which forms
11、 a reddish orangecomplex with Fe+.The intensity of the color is measured at460 nm with a spectrophotometer or filter photometer.4.Significance and Use4.1 These test methods are used to determine trace amountsof volatile chlorides in butane-butene mixtures.Such informa-tion is valuable in cases where
12、 chloride is deleterious in the useof this product;also,chloride contributes to corrosion prob-lems in processing units in instances where further processingof this material is involved.5.Purity of Reagents5.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indic
13、ated,it is intended thatall reagents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,1These test methods are under the jurisdiction of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricants and are the direct responsibilityof
14、 Subcommittee D02.D0.04 on C4 Hydrocarbons.Current edition approved May 1,2014.Published July 2014.Originally approvedin 1965.Last previous edition approved in 2009 as D2384 83(2009).DOI:10.1520/D2384-83R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Se
15、rvice 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 where such specifications are available.3Other gr
16、ades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.5.2 References to water shall be understood to meanchloride-free distilled or deionized water.5.3(WarningIn view of the common occurrence ofchloride in reagents and laboratory air,special care must betaken during preparation and storage of reagents to avoidcontamination.They should be isolated from other reagentsand used solely for t
