1.1 本试验方法包括测定苯乙烯中常见的杂质，并使用这些值通过气相色谱法测定苯乙烯的纯度。商业苯乙烯中的典型杂质存在于 表1 . 1.2 本试验方法适用于杂质浓度高达1 %. 1.2.1 检测限为0.0003质量%，定量限为0.0010质量%。 1.2.2 LOD和LOQ是使用ILS结果中的数据计算的 n -表3中的丙苯。 1.3 在使用该方法确定测试结果是否符合适用规范时，应根据四舍五入对结果进行四舍五入- 非实践方法 E29年 . 1.4 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。 1.5 本标准无意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。 有关具体的危险说明，请参阅第节 9 . 1.6 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 本试验方法旨在根据苯乙烯中通常存在的杂质获得苯乙烯纯度，并可用于最终产品检查和过程控制。 5.2 该测试方法将检测以下所示的杂质: 表1 ，含十个碳或更少的非芳香烃，以及其他有特定杂质标准的物质。如果存在未知杂质，则无法确定绝对纯度。

1.1 This test method covers the determination of the impurities typically found in styrene and uses those values to determine the purity of styrene by difference by gas chromatography. Typical impurities in commercial styrene are found in Table 1 . 1.2 This test method is applicable to impurity concentrations up to 1 %. 1.2.1 The limit of detection is 0.0003 mass % and the limit of quantitation is 0.0010 mass %. 1.2.2 LOD and LOQ were calculated using data from ILS results for n -propylbenzene in Table 3. 1.3 In determining the conformance of the test results using this method to applicable specifications, results shall be rounded off in accordance with the rounding-off method of Practice E29 . 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address all 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. For a specific hazard statement, see Section 9 . 1.6 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 This test method is designed to obtain styrene purity on the basis of impurities normally present in styrene and may be used for final product inspections and process control. 5.2 This test method will detect the impurities shown in Table 1 , non-aromatic hydrocarbons containing ten carbons or less, and others where specific impurity standards are available. Absolute purity cannot be determined if unknown impurities are present.