新型异双四齿双席夫碱铜(Ⅱ)配合物为中性载体的高选择性硫氰酸根离子选择电极的研究  

Study on highly selective thiocyanate electrode based on copper(Ⅱ) complex with unsymmetrical schiff base as a neutral carrier

作　　者：梁克中[1] 牟维君[2] 

机构地区：[1]重庆三峡学院化学与环境工程系,重庆404000 [2]重庆三峡医药高等专科学校,重庆404000

出　　处：《分析试验室》2008年第9期57-61,共5页Chinese Journal of Analysis Laboratory

基　　金：重庆市教委科研(KJ081103)项目资助

摘　　要：研究了用乙二胺与乙酰丙酮、水杨醛反应合成的一种异双四齿席夫碱铜（Ⅱ）配合物[Cu（Ⅱ）-L]为中性载体的PVC膜电极，该电极对硫氰酸根离子（SCN^-）具有优良的电位响应特性并呈现出反Hofmeister选择性行为，其选择性次序为：SCN^-〉Sal^-〉ClO4^-〉I^-〉Br^-〉NO3^-〉Cl^-〉NO2^-〉SO3^2-〉SO4^2-〉H2PO4^-。电极在pH5．0的磷酸盐缓冲体系中，对SCN^-在1．0×10^-1～2．0×10^-6mol／L浓度范围内呈近能斯特响应，斜率为-57．8mV／dec（25℃），检出限为1．0×10^-6mol／L。利用交流阻抗和紫外可见光谱初步研究了阴离子与载体的作用机理，结果表明配合物中心金属原子的结构以及载体本身的结构与电极的响应行为之间有非常密切的构效关系。将电极初步应用于实际样品废水中，结果与HPLC法相符合。A new highly selective thiocyanate electrode based on copper（Ⅱ ） complex with unsyrmnetrical schiff base [ Cu（ Ⅱ ）-L] as a neutral carrier is developed, which displays an anti-hofmeister selectivity sequence： SCN^- 〉 Sal^- 〉 ClO4^- 〉 I^- 〉 Br^- 〉 NO3^- 〉 Cl^- 〉 NO2^- 〉 SO3^2- 〉 SO4^2- 〉 H2PO4^- . The electrode exhibits nemstian potential linear range to thiocyanate from 1 .0×10^-1 to 2.0 × 10^-6 mol/L with a detection limit of 1.0 × 10^-6 mol/L and a slope of 57.8 mV/dec in pH 5.0 of phosphorate buffer solution at 25 ℃. The response mechanism is discussed in view of the a.c. impedance technique and the UV spectroscopy. These deviations result from the direct interaction between the central metal arid the analyte ion and steric effect associated with the structure of the can＇ier. The electrode has the advantages of simplicity, fast response, fair stability and reproducibility and low detection limit. The electrode can be applied to waste water analysis and the results obtained are in good agreement with the results given by HPLC.

关 键 词：异双四齿席夫碱铜(Ⅱ)配合物 中性载体 离子选择性电极 硫氰酸根 

分 类 号：O657.15[理学—分析化学]