1、Designation:D820718Standard Test Method forDetermination of Metals in Purified Terephthalic Acid(PAT)by Atomic Absorption(AA)Spectrometry1This standard is issued under the fixed designation D8207;the number immediately following the designation indicates the year oforiginal adoption or,in the case o
2、f 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 aluminum,chromium,cobalt,titanium,iron,manganese,molybd
3、enum,sodium and nickel in purified terephthalic acid(PAT)bygraphite furnace atomic absorption(GFAA)spectrometry.It isapplicable to PAT samples containing sodium,chromium,cobalt,titanium,manganese,molybdenum and nickel over0.004 mg/kg,and iron and aluminum over 0.054 mg/kg.1.2 In determining the conf
4、ormance of the test results usingthis method to applicable specification,results shall be roundedoff in accordance with the rounding-off method of PracticeE29.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard
5、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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Some specific hazards
6、statements are given in 6.3,6.10,6.11,Section,and 9.1.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued
7、 by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD4790 Terminology of Aromatic Hydrocarbons and RelatedChemicalsD6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydroca
8、rbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE300 Practice for Sampling Industrial ChemicalsE691 Practice for Conducting an Interlaboratory Study
9、toDetermine the Precision of a Test MethodE1184 Practice for Determination of Elements by GraphiteFurnace Atomic Absorption Spectrometry2.2 Other Document:3OSHA Regulations,29 CFR paragraphs 1910.1000 and1910.12003.Summary of Test Method3.1 PAT sample in a platinum crucible is ignited and burned,the
10、n ashed at 750C approximately for 45 min in a mufflefurnace,and finally dissolved with sulfuric acid solution.Thesample solution is analyzed by graphite furnace atomic absorp-tion spectrophotometer.The external standard calibration isused for quantification.4.Significance and Use4.1 The presence of
11、metals in PAT used for the productionof polyester is undesirable because they may speed up or slowdown the reaction and be impurities in the final product.4.2 Determination of metals in PAT is often required.Thistest method is suitable for setting specifications and for use asan internal quality con
12、trol tool where these products areproduced or used.5.Apparatus5.1 AtomicAbsorptionSpectrometerwithGraphiteFurnace,having background correction capable of removingnonspecific absorbance.1This test method is under the jurisdiction of ASTM Committee D16 onAromatic,Industrial,Specialty and Related Chemi
13、cals and is the direct responsi-bility of Subcommittee D16.02 on Oxygenated Aromatics.Current edition approved June 1,2018.Published August 2018.DOI:10.1520/D8207-18.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book
14、of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from U.S.Government Printing Office,Superintendent ofDocuments,732 N.Capitol St.,NW,Washington,DC 20401-0001,http:/www.access.gpo.gov.Copyright ASTM International,100 Barr Harbor Drive,PO B
15、ox C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the
16、World Trade Organization Technical Barriers to Trade(TBT)Committee.1 5.2 Hollow Cathode Lamps.5.3 Autosampler or Manual Pipettor.5.4 Analytical Balance,readable to 60.0001 g.5.5 Muffle Furnace,with temperature control as(750 625C).5.6 Platinum Crucible,with capacity of 60 to 100 mL andweight no more than 22 g.6.Reagents and Materials6.1 Purity of ReagentsUnless otherwise indicated,it isintended that all reagents shall conform to the reagent gradespecification of the analytical reagents of theAme