纳米PbO2修饰电极安培检测器流动注射法快速测定化学需氧量

采用以纳米PbO₂修饰电极为工作电极的安培检测器,用流动注射法快速检测水体中的化学需氧量(COD).根据纳米PbO₂修饰电极催化氧化电流的大小测定样品的COD值,在50-1 200 mg/L COD的范围内,电流响应与标准水样中的COD_Cr值呈线性关系,检出限为20 mg/L.该法不需对水样进行预处理,不使用有毒试剂,无二次污染,具有快速、简便、进样量少及工作电极使用寿命长等优点,与COD_Cr国家标准分析法对比具有较好的相关性.

Determination of Chemical Oxygen Demand by Flow Injection Analysis Using Amperometric Detector with Nano PbO 2 Modified Electrode

An electrochemical detection system with a nanometer lead dioxide modified electrode for flow(injection) analysis to determine chemical oxygen demand(COD) is described.The measuring principle is based on the current response on the PbO₂ modified electrode which is proportional to the COD value of the standard water sample range of 50-1 200 mg/L.Under the optimized experiment conditions,and the detection limit is 20 mg/L.When this method was applied to the determination of real water samples,it has the advantage of no sample pretreatment,short analysis time,simplicity, a minimum sample and reagent consumption and easy automation.Additionally,the method for determination of COD is in excellent correspondence with the values obtained by conventional method.