ASTM_D_5815_-_95_2001e1.pdf

Designation:D 5815 95(Reapproved 2001)e1Standard Test Method forDetermination of Phenolic Antioxidants and Erucamide SlipAdditives in Linear Low-Density Polyethylene Using LiquidChromatography(LC)1This standard is issued under the fixed designation D 5815;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(e)indicates an editorial change since the last revision or reapproval.e1NOTESeveral sections were changed editorially in March 2001.1.Scope1.1 This test method covers a liquid-chromatographic pro-cedure for the separation of some additives currently used inlinear low-density polyethylene.These additives are extractedwith either isobutanol or isopropanol prior to liquid-chromatographic separation.The ultraviolet absorbance(200nm)of the compound(s)is measured;quantitation is performedusing the internal standard method.1.2 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.Specific precau-tionary statements are given in Section 9.NOTE1There is no equivalent ISO standard.2.Referenced Documents2.1 ASTM Standards:D 883 Terminology Relating to Plastics2D 1600 Terminology for 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.Terminology3.1 Definitions:3.1.1 For definitions of plastic terms used in this testmethod,see Terminologies D 883 and D 1600.3.2 For units,symbols,and abbreviations used in this testmethod refer to Terminology E 131 or IEEE/ASTM SI-10.3.3 Abbreviations:Abbreviations:3.3.1 BHEB2,6-di-t-butyl-4-ethyl-phenol or butylated hy-droxyethyl benzene.3.3.2 BHT2,6-di-t-butyl-cresol or butylated hydroxy tolu-ene.3.3.3 LCLiquid chromatography.3.3.4 LLDPELinear low-density polyethylene.3.4 Trade Names:3.5 Irganox 1010Tetrakismethylene(3,5-di-t-butyl-4-hydroxy hydrocinnamate)methane.3.6 Irganox 1076Octadecyl-3,5-di-t-butyl-4-hydroxy hy-drocinnamate.3.7 Isonox 12962,28-ethylidene bis(4,6-di-t-butyl phe-nol).3.8 Kemamide-ECis-13-docosenamide,erucamide.3.9 Tinuvin P2(28-hydroxy-58-methyl phenyl)benzotriaz-ole.4.Summary of Test Method4.1 The LLDPE sample is ground to a 20-mesh particle sizeand extracted by refluxing with either isobutanol or isopro-panol.4.2 The solvent extract is analyzed by liquid chromatogra-phy.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.NOTE2Isopropanol is recommended as the extraction solvent forlower crystallinity LLDPE(0.925 density and below)and isobutanol isrecommended as the extraction solvent for higher crystallinity LLDPEcontaining Irganox 1010.1This test method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70Analytical Methods.Current edition approved Oct.10,1995.Published December 1995.2Annual Book of ASTM Standards,Vol 08.01.3Annual Book of ASTM Standards,Vol 03.06.4Annual Book of ASTM Standards,Vol 14.02.5Annual Book of ASTM Standards,Vol 14.04.6CAS No.112845.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.5.Significance and Use5.1 Separation and identification of stabilizers used in themanufacture of linear low-density polyethylene are necessaryin order to correlate performance properties with polymercomposition.This test method provides a means to determineBHT,BHEB,Isonox 129,erucamide slip,Irganox 1010,andIrganox 1076 levels in linear low-density polyethylenesamples.This test method should be applicable for the deter-mination of other antioxidants such as Ultranox 626,Ethanox330,Santanox R,and Topanol CA,but the applicability of thistest method has not been investigated for these antioxidants.5.2 The additive extraction procedure is made effective bythe insolubility of the polymer sample in solvents generallyused for liquid chromatographic analysis.5.3 Under optimum conditions,the lowest level of detectionfor a phenolic antioxidant is approximately 2 ppm.5.4 Other methods that have been successfully used toremove additives from the plastics matrix include thin film,microwave,ultrasonic,and supercritical fluid extractions.Other methods have been successfully used to separate additiveincluding SFC and GC.6.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 shou