An anodic stripping voltammetric method for the determination of arsenite using Au - Pd bimetallic nanoparticles( Au-Pd NPs) modified glassy carbon electrode (Au -Pd/GCE) was developed. The structural information and electrochemical activities of the synthesized Au - Pd nanoparti-cles were investigated with UV - Vis spectroscopy, high resolution transmission electron microscopy ( HRTEM) and cyclic voltammetric ( CV) method. The determination of arsenic was conducted by square wave voltammetric(SWV) method. Effects of deposition potential and SWV parameters (such as frequency, increment and amplitude) on the current intensity of arsenite were investigated. The results showed that Au - Pd bimetallic nanoparticles presented a core - shell structure in shape and the modified electrode exhibited the characteristic peaks of both Au and Pd. A sensitive anodic stripping peak of arsenite appeared at about 0. 30 V, and the peak current was linear with concentration of arsenite in the range of 0. 5-20 μg/L with a limit of detection ( LOD) of 0. 15 μg/L, which is far below the maximum guideline value(10μ/L) set by World Health Organization(WHO). The modified electrode exhibited a good repeatability toward the consecutive determination of arsenite. The interference experiments also showed that except for Cu( II ), the existance of Pb( II ) , Cd( H ) and Zn( II) would not affect the detection of As( 1).%研究了金-钯双金属纳米颗粒修饰电极测定痕量砷的阳极溶出伏安法.采用紫外可见分光光度法、高分辨透射电镜及循环伏安法对颗粒的结构和电化学特性进行表征.采用方波伏安法测定三价砷,探讨了富集电位和方波伏安参数如频率、增幅、波幅以及干扰离子等对测定结果的影响.实验结果表明:金-钯双金属纳米颗粒呈壳-核结构；砷在0.30 V出现灵敏的阳极溶出伏安峰,峰电流与砷质量浓度在0.5～20 μg/L范围内呈良好的线性关系,检出限为0.15 μg/L;所制备的修饰电极重现性好,可用于三价砷的重复测定.共存离子Cu(Ⅱ)会影响三价砷的测定,而Pb(Ⅱ)、Cd(Ⅱ)、Zn(Ⅱ)等离子的存在对测定结果无影响.
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