表面活性剂和洗涤剂 含水量的测定 卡尔·费休法

[中文适用范围]： 本国际标准规定了使用卡尔费休试剂的两种滴定方法（容量法和库仑法），用于测定表面活性剂和洗涤剂中的水分含量。这些方法适用于粉末、糊状物和溶液形式的产品。仅当各产品的具体标准中指明时，才适用这些方法。由于碱性化合物会与卡尔费休试剂反应，因此对于含有硅酸铝、碳酸盐、氢氧化物或硼酸盐的样品，该方法测得的值会偏高。因此，在测定水分含量之前，需要分析样品中是否存在此类碱金属盐。 [外文原描述]： ISO 4317:2011 specifies two titration methods (volumetric and coulometric) using Karl Fischer reagent for the determination of the water content of surface active agents and detergents. These methods are applicable to products in the form of powders, pastes and solutions. They are applicable only if so indicated in the specific standard for each product. As alkaline compounds react with Karl Fischer reagent, the methods give values which are too high in the case of samples containing alkali metal silicates, carbonates, hydroxides or borates. Therefore, samples need to be analysed for the presence of such alkali metal salts prior to the determination of the water content.