丽春红2R-高碘酸钾催化动力学体系光度法测定痕量铁

A Kinetic Spectrophotometric Method for the Determination of Trace Iron(Ⅲ) with Ponceau 2R and Potassium Periodic

在硫酸介质中,微量铁(Ⅲ)能显著催化高碘酸钾氧化丽春红2R(PR)的褪色反应。研究了该指示反应的最佳反应条件和动力学参数,建立了一个测定痕量铁的新的催化动力学分析方法。方法的线性范围为0.010～1.0μg/25mL,检出限为1.18×10-9g/mL。用本法测定了中草药及食品中铁的含量,结果满意。

A new kinetic method for the determination of trace Fe(Ⅲ) was established based on the catalytic action of Fe(Ⅲ) on the oxidative fading reaction between Ponceau 2R and KIO_4 in sulfuric acid medium. The optimum conditions and the kinetic parameters were investigated. The linear range for the determination of Fe^(3+) by the proposed method was 0.010～1.0 μg/25mL. The detection limit was 1.18×10^(-9) g/mL. The method has been used for the determination of trace iron(Ⅲ) in the Chinese herbal medicine and food with a satisfactory result.