1.1 本试验方法涵盖了分离聚乙烯塑料中当前使用的主要和次要抗氧化剂和滑液添加剂的液相色谱程序。用异丙醇（树脂密度<0.94 g/cm）提取这些添加剂 3. )或环己烷（树脂密度>0.94 g/cm 3. )在液相色谱分离之前。测量洗脱化合物的紫外线吸光度，并使用外部校准进行定量。 1.2 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 第节给出了具体的预防说明 9 . 注1: 没有已知的ISO等效于本标准。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 为了将性能与聚合物组成联系起来，有必要分离和鉴定聚乙烯树脂制造中使用的稳定剂。本试验方法提供了一种方法来确定表1中列出的聚合物添加剂 表1 在聚乙烯样品中。本试验方法能够测定其他抗氧化剂，但尚未研究其在提取过程中的稳定性。 5.2 添加剂萃取程序因聚合物样品在通常用于液相色谱分析的溶剂中的溶解度相对较低而有效。 在该方法中，选择异丙醇和环己烷是因为其优异的萃取效率以及安全原因。也可以使用其他溶剂，包括乙酸乙酯、异丁醇、氯仿和二氯甲烷。 5.3 用于从聚合物基质中去除添加剂的回流以外的方法，包括加压液体、微波、超声波和超临界流体萃取。为了分离提取的添加剂，SFC和GC已成功用于几种添加剂。 5.4 在最佳条件下，抗氧化剂的最低检测水平约为2 ppm。

1.1 This test method covers a liquid-chromatographic procedure for the separation of primary and secondary antioxidant and slip additives currently used in polyethylene plastics. These additives are extracted with either isopropanol (resin densities < 0.94 g/cm 3 ) or cyclohexane (resin densities > 0.94 g/cm 3 ) prior to liquid-chromatographic separation. The ultraviolet absorbance of the eluting compound(s) is measured and quantitation is performed using external calibration. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 9 . Note 1: There is no known ISO equivalent to this standard. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Separation and identification of stabilizers used in the manufacture of polyethylene resins are necessary in order to correlate performance properties with polymer composition. This test method provides a means to determine the polymer additives listed in Table 1 in polyethylene samples. This test method is capable of the determination of other antioxidants, but the stability of these during extraction has not been investigated. 5.2 The additive extraction procedure is made effective by the relatively low solubility of the polymer sample in solvents generally used for liquid chromatographic analysis. In this method, isopropanol and cyclohexane were chosen because of their excellent extraction efficiencies as well as for safety reasons. Other solvents including ethylacetate, isobutanol, chloroform and methylene chloride can also be used. 5.3 Methods other than refluxing that have been used to remove additives from the polymer matrix including pressurized liquid, microwave, ultrasonic, and supercritical fluid extractions. For the separation of the extracted additives, SFC and GC have been used successfully for several of the additives. 5.4 Under optimum conditions, the lowest level of detection for an antioxidant is approximately 2 ppm.