催化动力学方法测定粮食中痕量铁——Fe(Ⅲ)-碱性品红-H_2O_2体系

THE DETERMINATION OF TRACE IRON IN GRAIN WITH CATALYTIC KINETICS SPECTROPHOTOMETRY ——Fe(Ⅲ) FUCHSIN H 2O 2

在稀硫酸介质中，铁（Ⅲ）对过氧化氢氧化碱性品红的反应具有灵敏的催化作用。由此而建立的催化光度法灵敏度为１．１５×１０－９ｇ／ｍＬ，测定范围为０～０．６μｇ／２５ｍＬ。本方法用于粮食中痕量铁的测定，相对标准偏差＜６％，回收率９７％～１０４％。

A method has been developed for the determination of trace iron(Ⅲ) based on the fact that iron(Ⅲ) can catalyze the oxidation of basic fuchsin by hydrogen peroxide in H 2SO 4 medium.The sensitivity of the method is 1.15×10 -9 g/mL.The range of determination of iron(Ⅲ)is 0～0.6 μg/25 mL.The method has been applied to the determination of trace iron(Ⅲ) in the grain samples successfully.Its relative standard deviation is less than 6% and the recovery rate of the method is 97%～104%.