皮革.化学试验.可溶于二氯甲烷和游离脂肪酸的物质的测定

[中文适用范围]： 本标准规定了皮革中可溶于二氯甲烷的物质的测定方法。 此方法适用于所有类型的皮革。 并非所有脂肪和类似物质都可以用有机溶剂从皮革中提取；它们可能部分可溶，部分与皮革结合。 另一方面，溶剂可以溶解非脂肪物质，例如硫和浸渍剂，这两者都给脂肪的酸值和皂化值的测定带来困难。 本文件包括两种提取脂肪物质的技术：1）使用索氏提取器提取； 2) 使用加压萃取系统进行萃取。 由于提取经常与皮革中游离脂肪酸含量的测定一起进行，因此包括用于测定通过该方法提取的游离脂肪酸的合适程序。 该方法中描述的设备和技术也适用于用二氯甲烷以外的溶剂萃取（尽管高压萃取可能需要改变温度条件）。 [外文原描述]： This document specifies a method for the determination of the substances in leather which are soluble in dichloromethane. This method is applicable to all types of leather. Not all fatty and similar substances can be extracted from leather with organic solvents; they may be in part soluble and partly bound to the leather. On the other hand, the solvent can dissolve non-fatty substances, for example sulfur and impregnants, both of which cause difficulty in the determination of the acid value and saponification value of the fat. This document includes two techniques for extraction of the fatty substances: 1) extraction using the Soxhlet apparatus; and 2) extraction using a pressurized extraction system. As the extraction is frequently done in conjunction with determination of the free fatty acid content of the leather, a suitable procedure for determination of the free fatty acids extracted by this method is included. The apparatus and technique described in this method are also suitable for the extraction by solvents other than dichloromethane (although the temperature conditions may need to be varied for high pressure extraction).