1.1 本试验方法包括测定乙醇和乙醇溶液中乙酸的酸度。该试验方法可应用于含水量很少的乙醇样品（脱水醇）和含水量很大的溶液（低验证乙醇样品）。溶液包括变性醇，例如27.CFR中定义的美国变性乙醇配方。第21部分。该试验方法用于测定低于200 m⁄kg（ppm质量）的低酸度，不包括二氧化碳。 1.1.1 程序A-- 专门为电位滴定法测量酸度而开发。这就是裁判的方法。 1.1. 2. 程序B-- 专为通过颜色终点滴定法测量酸度而开发。 1.2 乙醇可以通过这种测试方法直接分析，只需最少的样品制备。 1.3 查阅当前和适当的安全数据表（SDS），了解有关毒性、急救程序、安全预防措施和适当的个人防护设备的详细信息。 1.4 单位-- 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 本标准并不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。 第节中给出了一些具体的危险说明 7. 关于危险。 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 这种测试方法可以定量测量酸度。低分子量有机酸（如乙酸）的极稀水溶液对许多金属具有高度腐蚀性。 5.2 乙醇中可接受的酸度水平因不同的规格而异，但通常低于200 mg/kg（ppm）。 为了确定产品质量是否符合规范，可能需要了解酸度。

1.1 This test method covers the determination of acidity as acetic acid in ethanol and ethanol solutions. This test method may be applied to ethanol samples containing very little water (dehydrated alcohols) to solutions with significant water (low proof ethanol samples). The solutions include denatured alcohols such as the U.S. denatured ethanol formulas defined in 27.CFR.Part 21. This test method is used for determining low levels of acidity, below 200 m⁄kg (ppm mass), with the exclusion of carbon dioxide. 1.1.1 Procedure A— Developed specifically for measurement of acidity by potentiometric titration. This is the referee method. 1.1.2 Procedure B— Developed specifically for measurement of acidity by color end point titration. 1.2 The ethanol may be analyzed directly by this test method with minimal sample preparation. 1.3 Review the current and appropriate Safety Data Sheets (SDS) for detailed information concerning toxicity, first aid procedures, and safety precautions and proper personal protective equipment. 1.4 Units— 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. Some specific hazards statements are given in Section 7 on Hazards. 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 measures acidity quantitatively. Very dilute aqueous solutions of low molecular mass organic acids, such as acetic acid, are highly corrosive to many metals. 5.2 Acceptable levels of acidity in ethanol can vary with different specifications, but in general, it is below 200 mg/kg (ppm). Knowledge of the acidity can be required to establish whether the product quality meets specification.