三苯基2-吡啶乙酸脂硫氰酸根离子电极的研究

On Highly Selective Thiocyanate Electrode Based on Triphenyltin(2-Pyridylthio)acetate Complex as Neutral Carriers

该文首次研究以三苯基2-吡啶乙酸脂为中性载体,制备了一种呈现出反Hofmeister选择性行为的PVC膜电极,其对硫氰酸根离子(SCN-)具有优良的电位响应特性,该电极在pH5.0的磷酸盐缓冲体系中具有最佳的电位响应,在1.0×10-1-5.0×10-5mol/L SCN-浓度范围呈近能斯特响应,斜率为52.7 mV/dec(25℃),检测下限为2.0×10-5mol/L。采用交流阻抗和光谱分析技术初步研究了载体与SCN-之间的作用关系。

A new highly selective thioeyanate PVC membran electrode firstly based on triphenyltin（2 -Pyridylthio）acetate complexes as neutral carrier is reported, which displays an anti - Hofmeister selectivity sequence. The electrode exhibits Nemstian potential linear range to thiocyanate from 1.0 × 10^-1to 5.0 ×10^-5 mol/L with a detection limit 2.0 ×10^-5mol/ L and a slope of 52.7 mV/dee 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 technique. These deviations result from the direct interaction between the central metal and the analyteion and sterie effect associated with thestructure of the carrier. The result shows that binuelear metallic complexes may become a new promising class of carrier for anions.