螯合剂铁螯合值测定方法比较

Test Methods of Iron Chelating Capacity of Chelating Agents and Comparison Thereof

采用络合滴定法、Fe(OH)_3沉淀法和碘量法等3种方法测定螯合剂EDTA的铁螯合值,并对测试结果和操作过程进行比较。结果表明,络合滴定法相对标准偏差最小,精度最高,操作简单、方便,且不受放置时间、溶液本身颜色的影响。故测定螯合剂铁螯合值时选用此法为宜。

Three methods,including complexometric titration method,ferric hydroxide sedimentation method and iodometric method,were used to determine iron chelating capacity of chelating agent EDTA.The results and operational process were compared.It was revealed that the complexometric titration method had the minimal relative standard deviation and the highest accuracy.It was easy to carry out,and was not influenced by the standing time and sample color.Thus,it was the most appropriate method to determine iron chelating capacity of chelating agents.