1.1 本试验方法涵盖并提供了高纯度（大于99.5）的分析 % 按体积） n -庚烷和 iso 辛烷（2,2,4-三甲基戊烷），用作确定燃料辛烷值的主要参考标准。浓度低于0.01的单个化合物 % 可以检测到。本试验方法规定的色谱柱可能不允许分离参考燃料中的所有杂质。 1.2 以国际单位制表示的数值应视为标准。 1.2.1 例外情况- 括号中给出的值仅供参考。 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。 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 本试验方法用于高纯度的规格分析 n -庚烷和 iso 辛烷值，用作ASTM爆震试验参考燃料。碳氢化合物杂质或污染物会对这些燃料的辛烷值产生不利影响，可通过该方法精确测定。

1.1 This test method covers and provides for the analysis of high-purity (greater than 99.5 % by volume) n -heptane and iso octane (2,2,4-trimethylpentane), which are used as primary reference standards in determining the octane number of a fuel. Individual compounds present in concentrations of less than 0.01 % can be detected. Columns specified by this test method may not allow separation of all impurities in reference fuels. 1.2 The values stated in SI units are to be regarded as the standard. 1.2.1 Exception— The values given in parentheses are for information only. 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. 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 This test method is used for specification analysis of high-purity n -heptane and iso octane, which are used as ASTM Knock Test Reference Fuels. Hydrocarbon impurities or contaminants, which can adversely affect the octane number of these fuels, are precisely determined by this method.