中文摘要：

对传统的磷酸电位滴定方法进行了系统研究，比较了两种沉淀剂（CaCl2和AgNO3）的滴定结果。提出的改进方法为：用CaCl2作沉淀剂，控制第二滴定突跃的pH在10．3以内，并将pU7作为第三滴定终点。测定结果表明：改进的磷酸电化滴定方法，不仅结果更准确，而且测定时间缩短一半。对3种磷酸酯／盐的含量分析测试结果表明，该改进的方法对提高相天目标产物含量、改进合成方法及精确调控产品性能更具指导意义。

英文摘要：

The conventional method for potenfiometric titration of phosphoric acid was investigated systemically. The titration results using CaCl2 and AgNO3 as precipitants were compared. The recommended modified method using CaCl2 as the precipitant suggested to control the sharp rise of pH value during the second titration at less than 10.3,and to set the third titration end point at a pH value of 7. The results on analysis of phosphoric acid and three different phosphate mixtures showed that the modified method was more accurate and faster than the conventional one. This modified potentiometric titration method will be helpful for identifying optimized synthetic conditions and controlling the performance of phosphate containing products.