This test method covered 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.

Formerly under the jurisdiction of Committee D20 on Plastics, this test method was withdrawn in February 2009 and replaced by Test Method D 6953 for Determination of Antioxidants and Erucamide Slip Additives in Polyethylene Using Liquid Chromatography (LC).

Separation and identification of stabilizers used in the manufacture of linear low-density polyethylene are necessary in order to correlate performance properties with polymer composition. This test method provides a means to determine BHT, BHEB, Isonox 129, erucamide slip, Irganox 1010, and Irganox 1076 levels in linear low-density polyethylene samples. This test method should be applicable for the determination of other antioxidants such as Ultranox 626, Ethanox 330, Santanox R, and Topanol CA, but the applicability of this test method has not been investigated for these antioxidants.

The additive extraction procedure is made effective by the insolubility of the polymer sample in solvents generally used for liquid chromatographic analysis.

Under optimum conditions, the lowest level of detection for a phenolic antioxidant is approximately 2 ppm.

Other methods that have been successfully used to remove additives from the plastics matrix include thin film, microwave, ultrasonic, and supercritical fluid extractions. Other methods have been successfully used to separate additive including SFC and GC.

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.