离子选择电极响应曲线平移法研究配合平衡——乙醇-水溶剂中Pb-NTA配合平衡的研究

A Study on Complexation Equilibrium by Parallel Motion of the Response Curve of Ion-Selective Electrode-Determination of Stability Constants of Pb-NTA Complex in Ethanol-water Solvents

本文提出了金属缓冲溶液中离子选择电极响应曲线平移法测定配合物的稳定常数。同时,研究了乙醇水混合溶剂中铅离子缓冲溶液的配制方法。在乙醇浓度为20;35;50wt％的乙醇水溶剂中(离子强度0.1)用这个方法测得Pb-NTA的配合物稳定常数对数值1gK分别为12.3,12.6,13.3。这些数值表明1g K-1/ε呈线性关系。

The method of parallel motion of response curve for lead ion-selective electrode in lead buffers is given to determine the stability constant of Pb-NTA complex in ethanol-water solvent. Besides, the method is studied for the preparation of lead buffers in ethanol-water solvent. In cthanol-water solvents containing 20%, 35% and 50% (w/w) ethanol, the stabiility constants determined, lgK_(PhNTA)are 12.3, 12.6 and 13.3 respectively. These results prove that the plot of log K_(PhNTA)-1/ε is linear.