中性载体双(N-乙基-N-苯基氨基二硫代甲酸)1,4-丁二醇酯PVC膜银离子选择电极的研制

The Preparation of Silver Ion Selective PVC Membrane Electrode Based on Neutral Ionophore Tetramethylene Bis(N-ethyl-N-phenyldithiolcarbamate)

采用双层膜电位法直接测定了溶剂聚合物膜中载体双（N-乙基-N-苯基氨基二硫代甲酸）1，4-丁二醇酯与金属离子生成的络合物生成常数。制备并考察了以双（N-乙基-N-苯基氨基二硫代甲酸）1，4-丁二醇酯为载体的银离子选择性电极的性能。实验结果表明：该选择电极对银离子有良好的灵敏度和高选择性，在1×10^-3～1×10^-6mol／L的浓度范围内响应斜率为60．2mV／pαAg^＋，检出限为2．3×10^-7mol／L，碱金属、碱土金属及过渡金属离子不干扰银的测定。该电极可作为Ag^＋准确滴定卤素阴离子的电位滴定指示电极，用于维生素B1药片中维生素B1含量的测定。

The ionophore-metal ion complex formation constants in solvent polymeric membrane were determined directly by potentiometry with a double-layer membrane electrode. A silver ion selective electrode with tetramethylene bis （N-ethyl-N-phenyldithiolcarbamate） as ionophore was prepared and characterized. The membrane electrode exhibited a good response to silver（ Ⅰ ） with a slope of 60. 2 mV/pαAg^＋ in the concentration range of 1 × 10^-3 -1 × 10^-6 mol/L AgNO3 solution, and the detection limit is 2. 3 × 10^-7 mol/L. The electrode has a highly selectivity for silver ion over alkali, alkline earth and common transition metal ions. The electrode can be successfully used as the indicator electrode in the titration of halide ions with silver ion and for the determination of Vitamin B1 in Vitamin B1 tablets.