催化褪色动力学光度法测定痕量Cr(Ⅲ)

Determination of Trace Chromium (Ⅲ) by Catalytic Kinetic Spectrophotometry

基于在pH为4的乙酸-乙酸钠缓冲介质中．Cr（Ⅲ）催化过氧化氢氧化亚甲基蓝褪色反应，研究了反应的最佳条件．测定了反应动力学参数，建立了一种动力学光度法测定Cr（Ⅲ）的新方法。方法的线性范围为0—40μg/L，检出下限为1．3×10^-10g/mL，用于水样中Cr（Ⅲ）的测定。

A new catalytic kinetic spectrophotometic method for the determination of trace chromium （ Ⅲ ） has been established. The method is based on the chromium（Ⅲ） catalyzes oxidation of methylene blue by hydrogen peroxide in acidic medium at pH4. The linear range of the determination is 0～40μg/L. The detection limit is 1.3 × 10^-10g/mL. The method has been applied to the determination of trace chromium（ Ⅲ ） in water with satisfactory result.