1、Designation:D115791(Reapproved 2014)Standard Test Method forTotal Inhibitor Content(TBC)of Light Hydrocarbons1,2This standard is issued under the fixed designation D1157;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of las
2、t 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 totalp-tertiary-butylcatechol inhibitor added to polymerization andrecycle grades
3、 of butadiene or to other C4hydrocarbonmixtures containing no phenolic material other than catechol orno oxidized phenolic material other than that derived fromoxidation of catechol.In general,all phenols and their quinoneoxidation products are included in the calculated catecholcontent.Small amount
4、s of polymer do not interfere.This testmethod is applicable over the range of TBC from 50 to500 mgkg.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 a
5、ny,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:3D1265 Practice for Sampling Liquefied Petroleum(LP)G
6、ases,Manual Method3.Summary of Test Method3.1 The catechol is separated from the butadiene by evapo-ration.The residue is dissolved in water and an excess of ferricchloride is added.The intensity of the yellow-colored complexis compared in a photoelectric colorimeter with that producedby known conce
7、ntrations of the catechol.4.Significance and Use4.1 p-tertiary-butylcatechol is commonly added to commer-cial butadiene in amounts of 50 to 250 mg/kg as an oxidationinhibitor.This test method is suitable for use by both producersand users of butadiene within the limitations described inSection 1.5.A
8、pparatus5.1 PhotometerA sensitive photoelectric photometer ca-pable of producing light of narrow spectral range that ispredominantly blue(425 nm).5.2 Graduates,100-mL.5.3 Volumetric Flasks,100-mL;or stoppered graduatedmixing cylinder,100-mL.5.4 Erlenmeyer Flasks,250-mL.5.5 Funnels,75-mm diameter.5.6
9、 Pipet,5-mL.6.Reagents6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.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 specifications are availab
10、le.4Other grades may beused,provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening theaccuracy of the determination.6.2 Purity of WaterReferences to water shall be under-stood to mean distilled water.6.3 Ferric Chloride,Standard Solution D
11、issolve 20.0 g offerric chloride(FeCl36H2O)in ethanol(95%).Add 9.2 mL ofHCl(sp gr 1.19),and then dilute with ethanol(95%)to1000 mL in a volumetric flask.6.4 p-Tertiary-Butylcatechol,Standard(WarningPotentially hazardous.May cause skin irritation or burns;can1This test method is under the jurisdictio
12、n of ASTM Committee D02 onPetroleum Products,Liquid Fuels,and Lubricantsand is the direct responsibility ofSubcommittee D02.D0.04 on C4 Hydrocarbons.Current edition approved May 1,2014.Published July 2014.Originally approvedin 1951.Last previous edition approved in 2009 as D1157 91(2009).DOI:10.1520
13、/D1157-91R14.2This test method was derived from the method developed and cooperativelytested by the Butadiene Producers Committee on Specifications and Methods ofAnalysis of the Office of Rubber Reserve,which appears in the ButadieneLaboratory Manual as Method 2.1.9.1.3For referenced ASTM standards,
14、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.4Reagent Chemicals,American Chemical Society Specifications,AmericanChemical Society,Washington,D
15、C.For Suggestions on the testing of reagents notlisted by the American Chemical Society,see Annual Standards for LaboratoryChemicals,BDH Ltd.,Poole,Dorset,U.K.,and the United States Pharmacopeiaand National Formulary,U.S.Pharmacopeial Convention,Inc.(USPC),Rockville,MD.Copyright ASTM International,1
16、00 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 be absorbed through the skin.May be harmful or fatal ifswallowed.Avoid contact with eyes;may burn and impairvision.May be harmful to respiratory system.May producequinones and flammable butylenes on decomposition.Use withadequate ventilation.Store in flammable liquids storage area.)Dissolve 0.63 g of p-tertiary-butylcatechol(95%minimumpurity)in 10 mL of ethanol(95%)and dilute with water to100 mL in a volumetric flask