ASTM_D_4590_-_13.pdf

Designation:D459013Standard Test Method forColorimetric Determination of p-tert-Butylcatechol In StyreneMonomer or AMS(Methylstyrene)by Spectrophotometry1This standard is issued under the fixed designation D4590;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.Scope*1.1 This test method is applicable to the determination ofresidual 4-tertiary-butylcatechol(TBC)in styrene monomer orAMS in the 1 to 100 mg/kg range.Any other compoundproducing color at 490 nm when contacted with aqueoussodium hydroxide solution will interfere.It may be compen-sated for by including it in the preparation of the standardsolutions,if its identity and concentration in the sample areknown.1.2 In determining the conformance of the test results usingthis method to applicable specifications,results shall berounded off in accordance with the rounding-off method ofPractice E29.1.3 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 specificstatements on hazards,see Section 8.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD3437 Practice for Sampling and Handling Liquid CyclicProductsD4790 Terminology of Aromatic Hydrocarbons and RelatedChemicalsD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 Other Document:OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.120033.Terminology3.1 See Terminology D4790 for definition of terms used inthis standard.4.Summary of Method4.1 Color is developed in the specimen by the addition ofcaustic in a methanol-octanol solvent.The intensity of the pinkcolor is measured with a spectrometer and compared to acalibration curve for quantitation.5.Significance and Use5.1 This test method is suitable for determining the quantityof TBC inhibitor,both for the protection against polymeriza-tion while in transit and storage,and for internal qualitycontrol.6.Apparatus6.1 Visible Range Spectrometer,equipped with absorptioncells providing light paths from 1 to 5 cm for use at approxi-mately 490 nm.6.2 Volumetric Pipets and PipetorsThe sample pipet vol-ume should be sized to fill the spectrometer absorption cell.Pipetor volumes must be scaled to the sample volume.Thisprocedure is written using a 15 mL sample volume.Thefollowing table shows how reagent pipetor volumes could bescaled to use a 5 mL sample volume.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.07 on Styrene,Ethylbenzene and C9 and C10 AromaticHydrocarbons.Current edition approved June 1,2013.Published June 2013.Originallyapproved in 1986.Last previous edition approved in 2009 as D4590 09.DOI:10.1520/D4590-13.2For 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.3Available from U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 Sample Pipet,mL0.15 NaOHPipetor,LMethanol Pipetor,L1530060051002007.Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests.Unless otherwise indicated,it is intended thatall reagents shall conform to the specification of the Committeeon Analytical Reagents of the American Chemical Society,where such specifications are available.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.7.2 4-Tertiary-Butylcatechol,Mp 52 to 55C.7.3 Toluene,ACS reagent grade.7.4 Methanol,reagent grade.7.5 n-Octanol,reagent grade.7.6 Aqueous Sodium Hydroxide,10 Normal(10N),reagentgrade.7.7 Alcoholic Sodium Hydroxide,approximately 0.15 N:Mix 0.75 mL of 10N Aqueous Sodium Hydroxide with 25 mLmethanol.With stirring,add 25 mL of n-octanol and then 0.75mL of water.Store the reagent in an