Pb（Ⅱ）－Cup络合物导数极谱波研究

A Study of the Derivative Polarographic Wave of Pb(Ⅱ)-Cup Complex

在ＰＨ为５～６的ＨＡｃ－六次甲基四胺溶液中，Ｐｂ（Ⅱ）与铜铁试剂产生的络合物在单扫描示波极谱仪上可观察到一灵敏的导数极谱波，其峰电位为－０．６４Ｖ（ＶＳ，ＳＣＥ），峰电流与铅浓度在９．６×１０－８～５．８×１０－６ｍｏｌ·Ｌ－１范围内成线性关系，检测限为１．９×１０－６ｍｏｌ·Ｌ－１，用以测定铅锌矿中铅的结果良好．同时研究了形成铅－铜铁试剂络合物吸附波的条件和性质，并用极谱法测定其络合比为１：１．

A complex of lead and cupferron, Pb (Ⅱ)-Cup, is formed in HAc-(CH2)6N4 solution at PH 5￣6. It shows a senstive derivative wave on single sweep polarography, with a peak potential at-0. 64 V(VS.SCE). A linear relationship holds between the peak current and lead concentration in the range of 9. 6×10-8￣5. 8×10-6 mol L-1. The detection limit for Pb is 1. 9×10-8 mol L-1. This system has been successfully appplied to the determination of Pb in Pb-Zn ore. Various conditions contributing to the formation of adsorption wave of the complex are studied on polarograghy and the properties of the wave are discussed. The complex has a complexing ratio of 1: 1,as determined by polarography.