1.1 本试验方法包括用气相色谱法测定环己烷的纯度。 1.2 本试验方法适用于杂质的测量，如 表1 ，是环己烷中可能存在的杂质。通过该方法可以在上限为400mg/kg的范围内分析杂质，但也可以适用于更宽的范围。检测限（LOD）为0.7 mg/kg，定量限（LOQ）为2.3 mg/kg。 注1: 根据苯的ILS数据计算LOD和LOQ。 1.3 以下内容适用于确定使用该测试方法的测试结果是否符合适用规范: 应按照实践中的舍入方法对结果进行舍入 第29页 . 1.4 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者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。 有关具体危害说明，请参阅第节 8. . 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 此测试方法适用于设定 表1 以及用作生产环己烷或在制造过程中使用环己烷的内部质量控制工具。它也可以用于涉及环己烷的开发或研究工作。 5.2 该试验方法可用于测定存在正常杂质的环己烷的纯度。如果环己烷中存在极高沸点或不寻常的杂质，则该测试方法不一定能检测到这些杂质，并且纯度计算将是错误的。

1.1 This test method covers the determination of the purity of cyclohexane by gas chromatography. 1.2 This test method has been found applicable to the measurement of impurities such as those found in Table 1 , which are impurities that may be found in cyclohexane. The impurities can be analyzed over a range with an upper limit of 400 mg/kg by this method, but may be applicable to a wider range. The limit of detection (LOD) is 0.7 mg/kg and the limit of quantitation (LOQ) is 2.3 mg/kg. Note 1: The LOD and LOQ were calculated from the ILS data for benzene. 1.3 The following applies for the purposes of determining the conformance of the test results using this test 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 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. For specific hazards statements, see Section 8 . 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 suitable for setting specifications on the materials referenced in Table 1 and for use as an internal quality control tool where cyclohexane is produced or is used in a manufacturing process. It may also be used in development or research work involving cyclohexane. 5.2 This test method is useful in determining the purity of cyclohexane with normal impurities present. If extremely high boiling or unusual impurities are present in the cyclohexane, this test method would not necessarily detect them and the purity calculation would be erroneous.