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    用杯4芳烃修饰玻碳电极循环伏安法测定水样中汞

    Cyclic Voltammetric Determination of Mercury with Calix4arene Modified Glassy Carbon Electrode

    • 摘要: 在含1.0×10-3mol·L-1杯4芳烃的0.1 mol·L-1四丁基高氯酸铵溶液中,在-0.2~-0.8 V(vs.Ag/AgCl)电位区间进行扫描,在玻碳电极表面电沉积一层杯4芳烃膜,从而制得杯4芳烃修饰玻碳电极。采用交流阻抗法和原子力显微镜对电极的表面性能进行了表征,采用循环伏安法对其电化学性能进行研究。试验发现:汞在杯4芳烃修饰玻碳电极上出现一个明显氧化峰,氧化峰电位为0.28 V(vs.Ag/AgCl)。在优化的试验条件下,Hg2+浓度在2.0×10-6~1.7×10-3mol·L-1范围内与氧化峰电流呈线性关系,检出限(3S/N)为5.0×10-7mol·L-1。修饰电极用于自制水样中汞的测定,所得结果与火焰原子吸收光谱法测定值相一致。

       

      Abstract: The modified electrode was prepared by electrodeposition of a film of calix4arene on the surface of glassy carbon electrode (GCE) through scanning over the potential range from -0.2 to -0.8 V (vs. Ag/AgCl) from a solution of 1.0×10-3mol·L-1 calix4arene dissolved in 0.1 mol·L-1 tetrabutyl ammonium perchlorate. The surface property of the calix4arene modified GCE were studied by AC impedance method and atomic force microscopy (AFM), and its electrochemical property studied by cyclic voltammetry. It was found that the calix4arene modified GCE showed a remarkable oxidation peak of Hg at the potential of 0.28 V (vs. Ag/AgCl). Under the optimized experimental conditions, linear relationship between values of oxidation peak current and concentration of mercury(Ⅱ) was obtained in the range of 2.0×10-6-1.7×10-3mol·L-1, with its detection limit (3S/N) of 5.0×10-7mol·L-1. The proposed method was used in the analysis of a simulated water sample, the results ontained were in conformity with those found by FAAS.

       

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