一般物料中对于微克量级的铁的分析均广泛使用萃取分离比色测定。然而对于常量或较高含量(0.5％～10％)铁的测定,若干年来国内外分析工作者大多习惯应用传统的重铬酸钾法即SnCl_2—HgCl_2还原、氧化——K_2Cr_2O_7滴定体系。这一经典方法具有准确、操作简易等优点,遗憾的是它需使用氯化高汞这一剧毒试剂,既污染环 General materials for the analysis of micrograms of iron are widely used extraction and separation colorimetric determination. However, for the determination of iron with a constant or high content (0.5% -10%), domestic and foreign analysts mostly used the traditional potassium dichromate method, that is, the SnCl_2-HgCl_2 reduction and oxidation-K_2Cr_2O_7 titration system for several years. This classic method is accurate, easy to operate and other advantages, it is regrettable that it requires the use of chlorinated high mercury, a highly toxic reagent, both pollution ring