摘要:
报道了以Cu(Ⅱ)配合物为中性载体的PVC膜电极对水杨酸根(Sal-)具有优良的电位响应性能和选择性并呈现出反Hofmeister选择性行为,其选择性从大到小次序为Sal-,ClO4-,SCN-,I-,NO2-,Cl-,F-,Br-,H2PO4-.在pH=4.0的磷酸盐缓冲体系中,电极电位呈现近能斯特响应,线性响应范围为3.0×10-6～1.0×10-1 mol/L Sal-,斜率为-58.7 mV/dec(20℃),检测下限为1.5×10-6 mol/L.采用交流阻抗技术研究了电极的响应机理,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.电极可用于药品分析.
Abstract:
The present article describes a new solvent polymeric membrane anion selective electrode based on complex of Cu(Ⅱ) as the neutral carrier. This PVC electrode demonstrates excellent selectivity toward the salicylate ion (Sal-) and anti Hofmeister selectivity, which is in the sequence of Sal- , ClO4- , SCN- , I- , NO2- , Cl- , F- , Br- ,H2PO4-. It exhibits a near-Nernstian potentiometric response in the range 3.0 × 10-6 ～1. 0 × 10-1 mol/L Sal- with a detection limit of 1.5×10-6 mol/L and a slope of -58.7 mV/pSal- in pH 4.0 in a phosphate buffer at 20 ℃. A study of the response mechanism(s) with the spectroscopic techniques showed that the electrode can be applied to the determination of salicylates in pharmaceutical preparations with satisfactory results.
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