光动力学法测定食盐中碘化物

Determination of Iodides in Table Salt by Photo-active Kinetic Analysis

在酸性介质中加入过量的硫代硫酸钠,与试液中的碘酸盐反应.用被光(紫外光)激活的溶液中之碘化钾产生的碘滴定剩余的硫代硫酸钠.结果表明,到达终点的时间与碘酸盐的含量成比例,线性范围为0～100μg/20mL,RSD为2.08％,标准加入回收率96％～106％.

A simple, rapid method for the analysis of microamounts of iodides in table salt was demonstrated in the paper. The method is based on the reaction of iodates with sodium thiosul-fate in an acidic medium. And an excess of sodium thiosulfate was titrated by the iodine produced by the activation of potassium iodide with UV-light in the solution. The concentration of iodates was measured by the reaction time needed to the end-point. The linear range of this method was 0-5. 00μg/mL and the RSD was 2. 08%. The recovery of standard adding was 96%-106%. The result of this method was accordance with the result of other method.