Nafion修饰金电极阳极溶出伏安法测定痕量碲

Anodic Stripping Voitammetry for De-termination of Trace Tellurium by NafionModified Gold Electrode

本文用Ｎａｆｉｏｎ修饰金盘电极，在０．０４ｍｏｌ／ＬＬｉＣｌｆｏｐＨ２的Ｈ＿（２）ＳＯ＿４底液中，阳极溶出伏安法测定痕量碲，研究了富集溶出过程的特性和优化条件，碲浓度在０．２～１５ｎｇ／ｍＬ范围内与溶出峰电流呈良好的线性关系（富集时间为２ｍｉｎ）。本法灵敏度高，选择性好，用于测定小麦粉和玉米粉中痕量碲，测定标准偏差小于０．０９７μｇ／ｇ，与ＩＣＰ测定结果比较其相对误差小于１６％。

The anodic stripping voltammetry forthe determination of trace tellurium byNafion modified gold electrode is described.In a base solution of 0.04mol/L LiCl adjust-ed to pH2.0 with H_(2)SO_4,a preconcentrationpotential of-0.2 and scan rate of 250mV/sfrom-0.2V to + 0.9V are chosen for use.Under optimum conditions the strippingpeak current at+0. 65V (vs. Ag/AgCl ) islinearly proportional to the concentration oftellurium(Ⅳ)in the range of 0.2～15μg/mL ( pre-electrolysis time is 2 min ).Themethod exhibits high sensitivity and selectiv-ity ,it has been applied to the determinationoftellurium in wheat and maize with satis-factory results. The standard deviation isless than 0. 097μg/g and the relative error isnot more than 16%.