基于安息香缩硫代氨基脲合铜(Ⅱ)为中性载体新型硫氰酸根离子选择性电极的研究

Study of a new selective thiocyanate electrode based on bebzoin thiosemicarbazone copper (Ⅱ) complex as neutral carrier

该文研究了以安息香缩硫代氨基脲合铜(Ⅱ)为中性载体的硫氰酸根离子(SCN^-)选择性电极,其选择性次序为:SCN^->I^->CIO_4^->NO_3^->Br^->SO_3^(2-)>Cl^->NO_2^->SO_4^(2-)。该电极在pH 5.0的磷酸盐缓冲体系中对SCN^-具有最佳的电位响应,在1.0×10^(-1)～8.0×10^(-5) mol/L SCN^-浓度范围呈近能斯特响应。斜率为-55.0 mV/pSCN^-(25℃),检测下限为4.0×10^(-5) mol/L。采用交流阻抗和紫外光谱分析技术研究了配合物中心金属原子以及配合物本身的结构对电极电位响应行为的作用机理。将该电极用于工业废水中硫氰酸根离子含量的测定,得到了满意的结果。

A new polymeric membrane thiocyanate selective electrode based on bebzoin thiosemicarbazone copper(Ⅱ) metallic complex [Cu(Ⅱ)-BBTSC] as neutral carrier is reported, which displays an anti-Hofmeister selectivity sequence in the following order: SCN^->I^-> ClO_4^-> NO_3^-> Br^-> SO_3^(2-) > Cl^-> NO_2^-> SO_4^(2-). The electrode exhibits Nernstian potential linear range to thiocyanate from 1.0×10^(-1) to 8.0×10^(-5) mol/L with a detection limit 4.0×10^(-5) mol/L and a slope of-55.0 mV/ pSCN-in pH 5.0 of phosphorate buffer solution at 25℃. The response mechanism is discussed in view of A. C. impedance technique and the UV spectroscopy technique. These deviations result from the direct interaction between the central metal and the analyte ion and steric effect associated with the structure of the carrier. The electrode can be applied to wastewater and the result is fair.