1.1 这些试验方法包括测定脂族化合物、脂环族化合物和酚类中连接在伯碳原子和仲碳原子上的羟基。 1.2 三种试验方法如下: 章节 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、 建议将试验方法A用于一般用途。测试方法B包括在内，以给出已广泛使用的方法的标准程序。当需要在最短时间内得出结果或需要反应的环境温度时，建议采用试验方法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），而不是使用其它两种方法获得的那些。 1.2.3 每种测试方法都包含精度说明。试验方法A和C的精度在很大的羟基含量范围内是一致的（在250至1600的羟基值范围内进行试验），而试验方法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上的精度。一般来说，试验方法A的精度大约是试验方法C的两倍。 在较低的羟基含量水平下，试验方法B具有与试验方法C大致相同的精度，但在较高的羟基含量含量水平下精度较差。 1.2.4 三种方法的干扰基本相同。一些化合物可以使用测试方法A或B进行分析，但不能使用测试方法C进行分析，因为强酸催化剂与被分析的化合物或在测定中形成的乙酸盐产物的干扰反应。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，特别是空间位阻仲醇，这些化合物在试验方法A和B中反应太慢或根本不反应。 注1: 试验方法中给出了测定羟基的其他方法 1995年1月 ， 2195年2月 ， 第326页 ， E335 和 E567 。 1.3 以国际单位制表示的数值应视为标准。本标准中不包括其他计量单位。 1.4 在使用该方法确定试验结果是否符合适用规范时，应根据实践中的舍入方法对结果进行舍入 第29页 。 1.5 查阅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。 1.6 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。 具体危害说明见第节 7. 。 1.7 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====== 4. 1. 羟基是一个重要的官能团，在许多中间体和最终用途应用中需要了解其含量。本文所述的测试方法用于测定伯羟基和仲羟基，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 In determining the conformance of the test results using this method to applicable specifications, results shall be rounded in accordance with the rounding off methods of Practice E29 . 1.5 Review the current appropriate Safety Data Sheets (SDS) for detailed information concerning toxicity, first aid procedures, and safety precautions. 1.6 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 hazards statements are given in Section 7 . 1.7 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.