本文首次提出双向溶出伏安法 ,并将该方法用于同时检测水溶液中的Au(Ⅲ )和Cu(Ⅱ ) .采用细菌修饰的碳糊电极做工作电极 ,于阳极富集 ,阴极溶出测定Au(Ⅲ ) ,同时在碳糊电极上再修饰上一层超细微粒金膜 .然后 ,在金电极上进行阴极富集 ,阳极溶出检测Cu(Ⅱ ) .该法仪器设备简单、操作简便 .Au(Ⅲ )与Cu(Ⅱ )的检测信号分别在阴极、阳极两个方向显示 ,分辨率高 .Au(Ⅲ )在 0 .2～ 1μg/mL、Cu(Ⅱ )在 2～ 10ng/mL浓度范围内 ,均有良好线性关系 ,其检测限依次为 2 0ng/mL和 0 .5ng/mL ,8次平行测定RSD小于 3%
A novel Two_way Stripping Voltammetry method for simultaneous determination of Au 3+ and Cu 2+ was reported in this paper. Because of the strongly electrostatic attraction of carbon paste electrode towards Au(Ⅲ) ion at positive potential and the biochemical contribution of Gram_positive bacteria strain DO1, the ion can be determined by cathodic stripping voltammetry. At the same time, Cu(Ⅱ) is reduced readily under the catalysis of ultra_fine gold particles, thereafter it can be determined by anode stripping voltammetry. There is no interference between the determination of Au 3+ and Cu 2+ . A perfect liner relationship between the concentrations of cations and peak heights in the range of 0.2～1.0 μg/mL(Au 3+ ) and 2～10 ng/mL(Cu 2+ ) respectively were observed. The detection limit is 20 ng/mL for Au(Ⅲ), and 0.5 ng/mL for Cu(Ⅱ). The relative standard deviation of the response to 5 μg/mL Au 3+ and 60 ng/mL Cu 2+ are less than 3%.
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