预镀铋膜修饰铂电极差分脉冲溶出伏安法测定痕量铅、镉  

Ex-situ Plating Bismuth Film on Platinum Electrode for the Determination of Trace Lead and Cadmium by Differential Pulse Stripping Voltammetry

作　　者：公维磊[1] 杜晓燕[1] 王舒然[1] 姜宪尘[1] 孙倩[1] 

机构地区：[1]哈尔滨医科大学公共卫生学院,哈尔滨150081

出　　处：《分析化学》2008年第2期177-181,共5页Chinese Journal of Analytical Chemistry

基　　金：黑龙江省科技攻关项目基金资助项目(No.GB05C101-02)

摘　　要：采用预镀铋膜法修饰铂电极，用该电极对痕量Pd、Cd同时进行了差分脉冲溶出伏安法测定，Pd、Cd在富集中和铋形成类似于汞齐的合金，溶出峰良好。讨论了在不同沉积液和沉积时间下得到的铋膜电极的性能和富集时间、富集电位及底液pH对金属离子测定的影响。在优化的实验条件下，分别对10—100μg／L、20～200μg／L和50～500μg／L3个不同浓度系列的Pb^2＋、Cd^2＋进行了同时测定，Pb、Cd溶出峰电流与Pb^2＋、Cd^2＋浓度呈良好的线性关系（r≥0．999），Pb^2＋、Cd^2＋浓度的线性范围均为10～500μg／L；富集时间为180s时，Pb^2＋、Cd^2＋的检出限分别为0．38μg／L和0．82μg／L。利用本方法测定了蔬菜中Pb的含量，并与原子荧光分析法做了对比，结果令人满意。Bismuth film modified platinum （Pt） electrode was prepared by an ex-situ plating for the simultaneous determination of a trace level of Pb^2＋ and Cd^2＋ by differential pulse stripping vohammetry （DPSV）. Pb and Cd formed alloys with bismuth and displayed well-defined peaks in differential pulse stripping vohammetry. The conditions of several key operational parameters such as the deposition time of Bi^3＋ , pH of supporting electrolyte, preconcentration time and potential were optimized. Following a 180-s preconcentration, the concentration series ranged from 10 - 100 μg/L, 20 - 200 μg/L and 50 - 500 μg/L for the simuhaneons determination of Pb^2＋ and Cd^2＋ ions were examined with all the correlation coefficients ≥0. 999. The oxidation peak currents change linearly with the concentration of Pb^2＋ and Cd^2＋ in the range of 10 -500 μg/L, and the detection limits were 0.38 and 0. 82 μg/L for Pb^2＋ and Cd^2＋ , respectively. The modified electrode was applied to the determination of Pb^2＋ ion in vegetables. Comparing the result with that of atomic fluorescence spectrometry （APS）, the concordance of results was satisfactory.

关 键 词：预镀铋膜 铂电极 差分脉冲溶出伏安法 重金属离子 

分 类 号：O657.1[理学—分析化学] TS252.7[理学—化学]