溴酸钾-碘离子体系催化动力学电位法测定痕量铜

Catalytic Kinetic Potentiometry for the Determination of Trace Copper by Use of the Potassium Bromate-Iodide System

以 ＫＢｒＯ３氧化Ｉ－的反应为指示反应，用碘离子选择电极跟踪Ｉ－。在适宜条件下，该指示反应为一级反应。反应速度可用电位的变化△Ｅ表示。当时间固定，△Ｅ与铜浓度在０～３ ｍｇ／Ｌ范围内呈线性关系，检出限为０．５μｇ／Ｌ。该方法已成功地用于土豆和红薯中痕量铜的测定。

A method is described for the determination. of trace copper using the oxidation of iodide by potassium bromate as indicator reaction. The concentration. of iodide is followed by iodide ion-selective electrode. Under the suitable conditions, the indicator reaction is firstorder and the reaction rate can be expressed as the change of potential (AE). The △E is linear with the concentration of copper in the range of 0-3 mg/L at fixed-time procedure. The detection limit of copper is 0. 2 μg/L. This method has been successfully applied to the determination of trace copper in potato and sweet potato.