1.1 这些试验方法包括测定脂肪族和脂环化合物及苯酚中附着在初级和次级碳原子上的羟基。 1.2 三种试验方法如下: 小节 试验方法A（压力瓶法） 8 – 14 试验方法B（回流法） 16 – 22 试验方法C（高氯酸催化法） 24 – 30 1.2.1 建议一般使用试验方法A。包括试验方法B，以提供广泛使用的方法的标准程序。当需要在最短时间内获得结果或需要反应的环境温度时，建议使用试验方法C。 1.2.2 使用试验方法A和B获得的结果基本相同，但使用试验方法C获得的结果更高（高达约4 % 相对）而不是使用其他两种方法获得的结果。 1.2.3 每种试验方法都包括精度说明。 测试方法A和C的精度在广泛的羟基含量范围内保持一致（在250到1600的羟基数范围内测试），而测试方法B在较高羟基含量水平下的精度低于在较低羟基含量水平下的精度。一般来说，试验方法A的精度约为试验方法C的两倍。试验方法B在较低的羟基含量水平下的精度与试验方法C大致相同，但在较高的羟基含量水平下的精度较差。 1.2.4 这三种方法的干扰基本相同。一些化合物可以使用试验方法A或B进行分析，但不使用试验方法C，因为强酸催化剂与所分析的化合物或测定过程中形成的醋酸盐产物发生干扰反应。然而，由于其反应性增加，试验方法C适用于测定某些化合物，特别是在试验方法A和B中反应过慢或根本不反应的空间位阻仲醇。 注1: 测试方法中给出了测定羟基的其他方法 D1957 , D2195 , E326 , E335 和 E567 . 1.3 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。 1.4 查看当前适当的安全数据表（SDS），了解有关毒性、急救程序和安全预防措施的详细信息。 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）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 具体危害说明见第节 7. . 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====== 4.1 羟基是一个重要的官能团，在许多中间体和最终用途中需要了解其含量。本文所述的试验方法用于测定初级和次级羟基，并可用于测定含有它们的化合物。

1.1 These test methods cover the determination of hydroxyl groups attached to primary and secondary carbon atoms in aliphatic and alicyclic compounds and phenols. 1.2 Three test methods are given as follows: Sections Test Method A (Pressure Bottle Method) 8 – 14 Test Method B (Reflux Method) 16 – 22 Test Method C (Perchloric Acid Catalyzed Method) 24 – 30 1.2.1 Test Method A is recommended for general use. Test Method B is included to give a standard procedure for the method that has been used widely. Test Method C is recommended when the results are required in a minimum period of time or where ambient temperature for the reaction is desired. 1.2.2 The results obtained using Test Methods A and B will be essentially the same, but the results obtained using Test Method C will be higher (up to approximately 4 % relative) than those obtained using the other two methods. 1.2.3 Statements on precision are included with each test method. The precision of Test Methods A and C is consistent over a wide range of hydroxyl content (tested over hydroxyl number range of 250 to 1600), whereas Test Method B is less precise at the higher hydroxyl content level than it is at the lower hydroxyl content level. In general, Test Method A is approximately two-fold as precise as Test Method C. Test Method B has approximately the same precision as Test Method C at the lower hydroxyl content level but poorer precision at the higher hydroxyl content level. 1.2.4 The interferences are essentially the same for the three methods. Some compounds can be analyzed using Test Methods A or B but not using Test Method C because of interfering reactions of the strong acid catalyst with the compound being analyzed or the acetate product formed in the determination. However, because of its increased reactivity, Test Method C is applicable for determination of some compounds, particularly sterically hindered secondary alcohols, which react too slowly or not at all in Test Methods A and B. Note 1: Other methods for determination of hydroxyl groups are given in Test Methods D1957 , D2195 , E326 , E335 , and E567 . 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 Review the current appropriate Safety Data Sheets (SDS) for detailed information concerning toxicity, first aid procedures, and safety precautions. 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 and health practices and determine the applicability of regulatory limitations prior to use. Specific hazards statements are given in Section 7 . 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 ====== 4.1 Hydroxyl is an important functional group, and knowledge of its content is required in many intermediate and end use applications. The test methods described herein are for the determination of primary and secondary hydroxyl groups and can be used for the assay of compounds containing them.