1.1 本实践涵盖了用于提取物单宁分析的液体提取物溶液的制备。 1.2 以SI单位表示的值应被视为标准值。本标准不包括其他计量单位。 1.3 一个 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 1.4 一个 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》中确立的国际公认的标准化原则制定的。======意义和用途====== 4.1 ●提取物中单宁的浓度必须降低至分析浓度（每升4 g单宁）进行分析。 4.2 ●植物单宁提取物是溶解度不同的成分的异质混合物。 4.3 这类提取物的溶解度受温度和浓度的影响，温度和浓度会影响组分颗粒的分散程度和尺寸。 4.4 虽然在热水中的溶解度比在冷水中好，但将提取物溶解并分散在热水中，然后让溶液缓慢冷却至标准室温是合适的。

1.1 This practice covers the preparation of a solution of liquid extract that is to be used in the tannin analysis of that extract. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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 ====== 4.1 The concentration of tannin in extracts must be reduced to analytical strength (4 g tannin per L) for analysis. 4.2 Vegetable tannin extracts are heterogeneous mixtures of components with varying solubility. 4.3 The solubility of such extracts is influenced by temperature and concentration, which affect the degree of dispersion and size of the component particles. 4.4 While the solubility is better in hot water than in cold water, it is appropriate to dissolve and disperse an extract in hot water and then let the solution cool slowly to standard room temperature.