ASTM D5815-95

Standard Test Method for Determination of Phenolic Antioxidants and Erucamide Slip Additives in Linear Low-Density Polyethylene Using Liquid Chromatograph (LC)

SCOPE
1.1 This test method covers a liquid-chromatographic procedure for the separation of some additives currently used in linear low-density polyethylene. These additives are extracted with either isobutanol or isopropanol prior to liquid-chromatographic separation. The ultraviolet absorbance (200 nm) of the compound(s) is measured; quantitation is performed using the internal standard method.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 9.
Note 1—There is no equivalent ISO standard.

General Information

• Status: Historical
• Publication Date: 31-Dec-2000
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.70 - Analytical Methods

Relations

• Replaced By: ASTM D5815-95(2001)e1 - Standard Test Method for Determination of Phenolic Antioxidants and Erucamide Slip Additives in Linear Low-Density Polyethylene Using Liquid Chromatograph (LC) (Withdrawn 2009)
• Effective Date: 01-Jan-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5815 – 95
Standard Test Method for
Determination of Phenolic Antioxidants and Erucamide Slip
Additives in Linear Low-Density Polyethylene Using Liquid
Chromatograph (LC)
This standard is issued under the fixed designation D 5815; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.3.3 LC—Liquid chromatography.
3.3.4 LLDPE—Linear low-density polyethylene.
1.1 This test method covers a liquid-chromatographic pro-
3.4 Trade Names:
cedure for the separation of some additives currently used in
3.5 Irganox 1010—Tetrakis[methylene(3,5-di-t-butyl-4-
linear low-density polyethylene. These additives are extracted
hydroxy hydrocinnamate)]methane.
with either isobutanol or isopropanol prior to liquid-
3.6 Irganox 1076—Octadecyl-3,5-di-t-butyl-4-hydroxy hy-
chromatographic separation. The ultraviolet absorbance (200
drocinnamate.
nm) of the compound(s) is measured; quantitation is performed
3.7 Isonox 129 —2,28-ethylidene bis (4,6-di-t-butyl phe-
using the internal standard method.
nol).
1.2 This standard does not purport to address all of the
3.8 Kemamide-E—Cis-13-docosenamide, erucamide.
safety concerns, if any, associated with its use. It is the
3.9 Tinuvin P—2(28-hydroxy-58-methyl phenyl)benzotriaz-
responsibility of the user of this standard to establish appro-
ole.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. Specific precau-
4. Summary of Test Method
tionary statements are given in Section 9.
4.1 The LLDPE sample is ground to a 20-mesh particle size
2. Referenced Documents and extracted by refluxing with either isobutanol or isopro-
panol.
2.1 ASTM Standards:
4.2 The solvent extract is examined by liquid chromatogra-
D 883 Terminology Relating to Plastics
phy.
D 1600 Terminology for Abbreviated Terms Relating to
4.3 Additive concentrations are determined relative to an
Plastics
internal standard (contained in the solvent) using reverse phase
E 131 Terminology Relating to Molecular Spectroscopy
chromatography (C-18 column) with ultraviolet (UV) detection
E 380 Practice for Use of the International System of Units
at 200 nm.
(SI)
E 691 Practice for Conducting an Interlaboratory Study to
NOTE 1—Isopropanol is recommended as the extraction solvent for
Determine the Precision of a Test Method
lower crystalinity LLDPE (0.925 density and below) and isobutanol is
recommended as the extraction solvent for higher crystalinity LLDPE
3. Terminology
containing Irganox 1010.
3.1 Definitions:
5. Significance and Use
3.1.1 For definitions of plastic terms used in this test
5.1 Separation and identification of stabilizers used in the
method, see Terminologies D 883 and D 1600.
manufacture of linear low-density polyethylene are necessary
3.2 For units, symbols, and abbreviations used in this test
in order to correlate performance properties with polymer
method refer to Terminology E 131 or Practice E 380.
composition. This test method provides a means to determine
3.3 Abbreviations:
BHT, BHEB, Isonox 129, erucamide slip, Irganox 1010, and
3.3.1 BHEB—2,6-di-t-butyl-4-ethyl-phenol or butylated hy-
Irganox 1076 levels in linear low-density polyethylene
droxyethyl benzene.
samples. This test method should be applicable for the deter-
3.3.2 BHT—2,6-di-t-butyl-cresol or butylated hydroxy tolu-
mination of other antioxidants such as Ultranox 626, Ethanox
ene.
330, Santanox R, and Topanol CA, but the applicability of this
test method has not been investigated for these antioxidants.
This test method is under the jurisdiction of ASTM Committee D-20 on Plastics
5.2 The additive extraction procedure is made effective by
and is the direct responsibility of Subcommittee D20.70Analytical Methods.
Current edition approved Oct. 10, 1995. Published December 1995. the insolubility of the polymer sample in solvents generally
Annual Book of ASTM Standards, Vol 08.01.
Annual Book of ASTM Standards, Vol 03.06.
4 5
Annual Book of ASTM Standards, Vol 14.02. CAS No. 112–84–5.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 5815
used for liquid chromatographic analysis. 8.4 Water, HPLC, or UV quality reagent, degassed by
5.3 Under optimum conditions, the lowest level of detection sparging with high-purity helium or by filtration under
for a phenolic antioxidant is approximately 2 ppm. vacuum.
5.4 Other methods that have been successfully used to 8.5 Acetonitrile, HPLC, spectroquality or chromatography
remove additives from the plastics matrix include thin film, quality reagent (a reagent whose UV cutoff is about 190 nm).
microwave, ultrasonic, and supercritical fluid extractions.
Other methods have been successfully used to separate additive 9. Safety Precautions
including SFC and GC.
9.1 Isopropanol and isobutanol are flammable. This extrac-
tion procedure should be carried out in a fume hood.
6. Interferences
6.1 Any material eluting at or near the same retention time
10. Preparation of Liquid Chromatograph
as the additive can cause erroneous results. A polymer-solvent-
10.1 Set the chromatograph to operate at the following
extract solution containing no internal standard should be
conditions:
examined to minimize the possibility of interferences.
6.2 A major source of interferences can be from solvent
NOTE 2—A Vydac 201HS5415, separations group, was used in this test
method. The gradient described in 10.1 provides complete separation of
impurities. For this reason, the solvents should be examined
antioxidants and slip using this C-18 column. If another column is used
prior to use by injecting a sample of solvent on the HPLC
then a different gradient may be needed to provide a complete separation
system and analyzing as in Section 10.
of the additives.
7. Apparatus
10.1.1 Initial Mobile Phase Condition—50 % acetonitrile:
7.1 Liquid Chromatograph, equipped with a variable wave-
50 % water.
length ultraviolet detector, heated column, and gradient elution
10.1.2 Final Mobile Phase Condition—100 % acetonitrile:
capabilities. The liquid chromatograph should be equipped
0 % water.
with a means for a 10-μL sample-solution injection such as a
10.1.3 Gradient Length—11 min.
sample loop.
10.1.4 Gradient Curve—Linear.
7.2 Chromatographic Column, RP-18, 5-μm particle size,
10.1.5 Flow Rate—1.0 mL/min.
15 cm by 4.6 mm.
10.1.6 Hold at 100 % Acetonitrile—0 % water for 8 min.
7.3 Computer System or Integrator, coupled with the chro-
10.1.7 At 19.1-Min Return to 50 % Acetonitrile—50 %
matograph is recommended to measure peak area.
water at a flow of 1.5 mL/min for 5 min.
7.4 Wiley Mill, equipped with a 20-mesh screen and water-
10.1.8 At 25-Min Return to 1.0 mL/min—Flow rate.
cooled jacket to prevent thermodegradation of antioxidants
10.1.9 Detector—Ultraviolet detector set at 200 nm, range
such as BHT and BHEB.
set at about 0.1 Aufs.
7.5 Recorder, millivolt scale dependent upon the output of
10.1.10 Chart Speed—0.5 in./min.
the detector.
10.1.11 Column—Reverse phase C-18, 5 μm, 15 cm by 4.6
7.6 Reflux Extraction Apparatus, consisting of a condenser,
mm.
(24/40 ground-glass joint), a flat bottom 125-mL flask having
10.1.12 Temperature—Column set at 60°C.
a 24/40 ground-glass joint, and a hot plate with magnetic
10.1.13 Sample Size—10 μL.
stirrer. See Fig. X1.1 in Appendix X1.
7.7 Filter System, (Teflon ), for nonaqueous solution
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