磷酸三钠中的氯化物,原采用准确度较高的氯化银重量法,但操作冗长。佛尔哈德容量法,终点不易观察;汞量法需用有毒试剂,而且要求严格的控制酸度;氯化银比浊法,虽有简便、快速等特点,但比浊法灵敏度不高;而银电极电位滴定法,具有准确、快速、灵敏、终点明显等优点。适用于含氯量大于0.009％的样品,准确度为0.43～3.6％。样品测定结果和氯化银重量法基本一致(见表2)。 Trisodium phosphate, the original use of higher accuracy of silver chloride gravimetric method, but the operation lengthy. Faulkner volumetric method, the end is not easy to observe; Mercury quantitative toxic reagents required, but also requires strict control of acidity; silver chloride turbidimetry, although simple, fast and so on, but turbidimetric sensitivity is not high; and Silver electrode potentiometric titration, with accurate, fast, sensitive, end-point obvious advantages. For samples containing more than 0.009% chlorine, the accuracy is 0.43 ~ 3.6%. The results of the sample and silver chloride gravimetric method are basically the same (see Table 2).