活化剂存在下H_2O_2氧化间乙酰基偶氮氯膦催化光度法测定痕量铁(Ⅲ)

Catalytic Spectrophotometric Determination of Trace Amounts of Iron(Ⅲ) with H_2O_2 Oxidizing m-Acetylchlorophosphonazo in the Existence of Active Agent

基于HAc-NaAc(pH3.0)缓冲介质中,邻菲罗啉对Fe()催化过氧化氢氧化间乙酰基偶氮氯膦褪色反应的活化作用,建立了催化光度法测定痕量铁的新反应体系。当有邻菲罗啉存在时Fe()才对褪色反应起显著催化作用,对于10mL溶液测定铁的线性范围0.0008—1.0μg,回归方程ΔA=0.427C-0.00092,r=0.9997,检出限为2.4×10-11g·mL-1,反应表观活化能127.9kJ·mol-1。应用于蒙药样品中痕量铁的测定,取得了满意的结果。

A new catalytic kinetic spectrophotometry for actermination of trace amount of iron（ Ⅲ） was developed based on catalytic discoloration reaction between H2O2 and m-acetylchlorophosphonazo by iron （Ⅲ） in HAc-NaAc （pH = 3） medium in the present of phenanthroline as active agent. The regression equation of △A=0.427C-0.00092,r=0. 9997,in the range of 0. 0008-1.0μg with 10mL solution was obtained, The limit of detection is 2.4 ×10^-11g ＊ mL^-1 and apparent activation energy is 127. 9kJ ＊ mol^-1. This method was applied to the determination of trace amounts of iron（Ⅲ ） in Mongolian medicine with satisfactory results.