新型中性载体高选择性水杨酸根离子选择性电极的研究

Studies on Highly Salicylate-Selective Ion Electrode Based on Novel Neutral Carriers

研究了基于水杨醛缩碳酰胺合铜（Ⅱ）[Cu（Ⅱ）-SAU]、水杨醛缩碳酰胺合镍（Ⅱ）[Ni（Ⅱ）-SAU]的金属配合物为中性载体的阴离子选择性电极．实验结果表明：以水杨醛缩碳酰胺合铜（Ⅱ）[Cu（Ⅱ）-SAU]为中性载体的离子选择性电极对水杨酸根离子（Sal^-）具有良好的电位响应特性，且呈现反Hofmeister行为，其选择性序列从大到小为：Sal^-，ClO4^-，I^-，SCN^-，NO2，NO3^-，Br^-，SO4^2-，SO3^2-，Cl^-．在pH=4．0的磷酸盐缓冲体系中该电极具有最佳的电位响应，在1．0×10^-1～9．6×10^-6mol／L浓度范围内呈近能斯特响应，斜率为-51．4mV／dec（25℃），检测下限为8．1×10^-6mol／L．采用交流阻抗研究了电极的响应机理，并将电极用于样品分析，结果比较满意．

A new PVC membrane electrode based on salicylaldehyde-urea metallic complexes as neutral carrier is described. The results show that electrode based on salicylaldehyde-urea copper（ Ⅱ ）[Cu（ Ⅱ ）-SAU] displays an excellent potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in following order： Sal^- , ClO4^- , I^- , SCN^- , NO2^- , NO3^- , Br^- , SO4^2- , SO3^2- , Cl^-. The electrode exhibits near Nernstian potential linear range of 1.0× 10^-1 --9.6× 10^- 6 mol/L with a detection limit of 8. 1 × 10^-6 mol/ L and a slope of -51.4 mV/pSal^- in pH=4.0 phosphorate buffer solution at 25 ℃. The response mechanism is discussed in view of the A. C. impedance technique. The electrode is applied to biological samples analysis with satisfactory results.