论文部分内容阅读
捷克科学家提出了一个比色分析法,可用来测定低含量的聚氧乙烯型表面活性剂。工作原理是基于:这一类表面活性剂在重金属离子存在下,会与磷钨酸形成一种能溶于碱或浓酸的络合物。通过络合物中钨的测定,即可以快速简便地测定表面活性剂的含量。既不需要中和,又不需要稀释(钨的测定是利用钨酸盐在氢醌中变成红色的原理)。所用的试剂是:(1)氯化钡,10%溶液(w/v);(2)稀盐酸,1:1;(3)磷钨酸水溶液,2%(w/v);(4)浓硫酸,98%;(5)氢醌溶液,5%(w/v),溶于98%浓硫酸。
Czech scientists have proposed a colorimetric assay that can be used to determine low levels of polyoxyethylene type surfactants. The working principle is based on the fact that surfactants of this type form complexes with phosphotungstic acid that are soluble in alkali or concentrated acids in the presence of heavy metal ions. By the determination of tungsten in the complex, the content of the surfactant can be measured quickly and easily. Neither neutral nor dilution is required (the determination of tungsten is based on the principle that tungstates turn red in hydroquinone). The reagents used are: (1) barium chloride, 10% solution (w / v); (2) dilute hydrochloric acid, 1: Concentrated sulfuric acid, 98%; (5) Hydroquinone solution, 5% (w / v), dissolved in 98% concentrated sulfuric acid.