乙基紫-H_2O_2体系催化动力学光度法测定痕量铜

Catalytic Kinetics Spectrophotometry for Determination of Trace Copper Using Ethyl Violet and H_2O_2 System

铜对 H2 O2 氧化乙基紫的反应有催化作用 ,测定反应液的吸光度可以跟踪反应 ,建立了一种测铜的新方法 .在适宜条件下该指示反应为零级反应 ,在一定时间下催化反应和非催化反应的吸光度之差 Δ A与铜浓度在 2～ 12 0 μg/ L 范围内呈线性 .干扰实验说明该方法有较好的选择性 .该方法已用于湖水和土豆的测定 ,结果可靠 .

A new kinetic method is described for the determination of copper based on its catalytic effect on the oxidation of ethyl violet by hydrogen peroxide. The reaction is followed spectrophotometrically by measuring the absorbance of reaction solutions. Under the suitable conditions, the indicator reaction is a pseudo zero order reaction and the ΔA, that is difference of the absorbance between catalysed and uncatalysed reaction solutions, is linear with the concentration of copper(Ⅱ) in the range of 2~120μg/L at fixed time procedure. The influence of foreign ions on the results is investigated and the new method is found to be adequately selective. This method is applied to determine the trace copper in lake water and potato with satisfactory results.