1、Designation:D 5524 94(Reapproved 2001)e1Standard Test Method forDetermination of Phenolic Antioxidants in High DensityPolyethylene Using Liquid Chromatography1This standard is issued under the fixed designation D 5524;the number immediately following the designation indicates the year oforiginal ado
2、ption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.e1NOTESeveral sections were changed editorially in March 2001.1.Scope1.1 This test metho
3、d covers a liquid-chromatographic pro-cedure for the separation of some additives currently used inhigh-density polyethylene.These additives are extracted withcyclohexane prior to liquid-chromatographic separation.Theultraviolet absorbance(200 nm)of the compound(s)is mea-sured;quantitation is perfor
4、med using the internal standardmethod.NOTE1There is no similar or equivalent ISO standard.1.2 The values stated in SI units are to be regarded as thestandard.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
5、this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.Specific precau-tionary statements are given in Section 9.2.Referenced Documents2.1 ASTM Standards:D 883 Terminology Relating to Plastics2D 1600 Terminology for
6、 Abbreviated Terms Relating toPlastics2E 131 Terminology Relating to Molecular Spectroscopy3E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method4IEEE/ASTM SI-10 Standard for Use of the InternationalSystem of Units(SI):The Modern Metric System53.Terminolog
7、y3.1 DefinitionsFor definitions of plastics terms used inthis test method,see Terminologies D 883 and D 1600.3.2 Symbols:SymbolsFor the units,symbols,and abbre-viations used in this test method,refer to Terminology E 131 orIEEE/ASTM SI-10.3.3 Abbreviations:Abbreviations:3.3.1 LCliquid chromatography
8、.3.3.2 HDPEhigh-density polyethylene.3.4 Trade Names:3.5 BHT2,6-di-t-butyl-cresol or butylated hydroxy tolu-ene.63.6 BHEB2,6-di-t-butyl-4-ethyl-phenol or butylated hy-droxyethyl benzene.73.7 Irganox 1010tetrakismethylene(3,5-di-t-butyl-4-hy-droxyhydrocinnamate)methane.83.8 Irganox 1076octadecyl-3,5-
9、di-t-butyl-4-hydroxy-hy-drocinnamate.93.9 Isonox 1292,28-ethylidene bis(4,6-di-t-butyl phenol).83.10 Tinuvin P2(28-hydroxy-58-methyl phenyl)benzotria-zole.84.Summary of Test Method4.1 The HDPE sample is ground to a 20-mesh particle sizeand extracted by refluxing with cyclohexane.4.2 The solvent extr
10、act is analyzed by LC.4.3 Additive concentrations are determined relative to aninternal standard(contained in the solvent)using reverse-phasechromatography(C-18 column)with ultraviolet(UV)detectionat 200 nm.5.Significance and Use5.1 Separation and identification of stabilizers used in themanufacture
11、 of HDPE are necessary in order to correlateperformance properties with polymer composition.This testmethod provides a means of determining BHT,BHEB,Isonox129,Irganox 1010,and Irganox 1076 levels in HDPE samples.This test method should be applicable for the determination of1This test method is under
12、 the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods.Current edition approved March 15,1994.Published May 1994.2Annual Book of ASTM Standards,Vol 08.01.3Annual Book of ASTM Standards,Vol 14.01.4Annual Book of ASTM Standards,V
13、ol 14.025Annual Book of ASTM Standards,Vol 14.046Available from PMC Specialties;Uniroyal,Inc.;Borg Warner;and RhonePoulank.7Available from R-M Industries and Gallard Schlesinger Corp.8Available Ciba-Geigy.9Available from Ciba-Geigy;Uniroyal,Inc.;Ethyl Corp.;and Borg Warner.1Copyright ASTM Internatio
14、nal,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.other antioxidants such as Cyanox 425,Cyanox 1790,Cyanox2246,Ultranox 236,and Ultranox 246,but the applicability ofthis test method has not been investigated for these antioxi-dants.5.2 The additive-extraction proced
15、ure is made effective bythe insolubility of the polymer sample in solvents generallyused for liquid chromatographic analysis.5.3 The lowest level of detection for a phenolic antioxidantis approximately 2 ppm under optimum conditions.5.4 Other procedures that have been used successfully toremove addi
16、tives from the plastics matrix include thin-film,microwave,10ultrasonic,11and supercritical fluid extrac-tions.11,12,13Procedures other than HPLC have been usedsuccessfully to separate additives,including SFC13and capil-lary GC.146.Interferences6.1 Any material eluting at or near the same retention timeas the additive can cause erroneous results.Apolymer-solvent-extract solution containing no internal standard should beexamined to minimize the possibility of interferences.6.2 A major source of i
