1.1 本试验方法用于测定可溶非鞣质和鞣质提取物、植物鞣制材料水提取物或鞣液溶液中鞣质的含量。该方法适用于液体、固体、糊状和粉末提取物的分析，以及原材料或废材料的提取物。 1.2 以国际单位制表示的数值应视为标准。国际单位制后括号中给出的值仅供参考，不被视为标准值。 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 本试验方法用于测定可溶非单宁的总可溶性固形物的比例，以及单宁在单宁提取物溶液或为单宁分析制备的原材料或废材料的水提取物中的比例。 5.2 样品是由鞣质提取物制备的分析溶液或由原材料或废材料制备的水提取物溶液的等分试样。 5.3 可溶性非单宁是指未被制备的皮粉材料吸收或结合的可溶性固体部分。 5.4 单宁是指被制备的皮粉材料吸收或结合的可溶性固体部分。 5.5 该测试方法的结果取决于许多变量，但尤其取决于: 5.5.1 溶液制备和储存的温度条件以及进行电流分析的温度； 5.5.2 沉积在滤纸上的高岭土膏层的均匀性和稠度； 5.5.3 溶液从移液管流出的速率； 5.5.4 与用于与溶液中单宁含量反应的皮粉性质有关的条件；因此，必须严格遵循该方法，以便在实验室内的样本之间和实验室之间的分析中获得可重复的结果。

1.1 This test method is intended for use in determining the quantity of soluble non-tannins and tannin in solutions of tannin extracts, water extracts of vegetable tanning materials, or tanning liquors. The method is applicable to the analysis of liquid, solid, pasty, and powdered extracts and to extracts of raw or spent materials. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses after SI units are for information only and are not considered 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 ====== 5.1 This test method is used to determine the proportion of the total soluble solids which are soluble non-tannins and the proportion which are tannins in a solution of tannin extract or in the water extract from raw or spent materials prepared for tannin analysis. 5.2 The specimens are aliquots from the analytical solutions prepared from tannin extracts or the water extract solutions prepared from raw or spent materials. 5.3 The soluble non-tannins are defined as the portion of the soluble solids which are not absorbed or bound by a prepared hide powder material. 5.4 The tannins are defined as the portion of the soluble solids which are absorbed or bound by a prepared hide powder material. 5.5 The results of this test method are dependent on a great many variables, but particularly upon: 5.5.1 The temperature conditions under which the solutions were prepared and stored and the temperature at which the current analysis is performed; 5.5.2 The uniformity and consistency of the Kaolin paste layer deposited onto the filter paper; 5.5.3 The rate of solution run-out from the pipette; 5.5.4 Conditions related to the properties of the hide powder used to react with the tannin content of the solution; etc. It is, therefore, essential that the method be followed exactly in order to obtain reproducible results both among specimens within a laboratory and for analyses between laboratories.