利用新的铁催化指示反应光度法　测定超痕量铁（Ⅲ）

Catalytic Spectrophotometric Determi-nation of Ultratrace Amounts of Irto(Ⅲ)with a New Indicator Reaction

在稀硫酸介质中，（Ⅲ）对溴酸钾氧化酸性铬深蓝的反应具有灵敏的催化作用，以此作为指示反应建立了催化光度法测定超痕量铁（Ⅲ）的新方法。方法检出限为１．４ｘ１０￣（－１０）ｇ／ｍＬ，线性范围为２～８０ｎｇ／ｍＬ，应用于自来水、大米及面粉中铁（Ⅲ）的测定，结果满意。

In this paper,a new indicator reactionhas been studied.It is based on the fact thatiron(Ⅲ)can catalyze the oxidation of acidchrome dark blue by KBrO_3 in H_2SO_4 medi-um.The detection limit of catalytic spec-trophotometry is 1.4 x10￣(-10)g/mL Fe￣(3+) andthe linear range is 2～80ng/6mL. Thismethod has been successfully applied to thedetermination of trace amounts of iron inwater and food samples.