新型PVC膜银离子选择电极的研制及应用

以合成的双(N-乙基-N-苯基氨基二硫代甲酸)1,3-丙二醇酯为载体,采用双层膜电位法直接测定了溶剂聚合物膜中载体与金属离子的络合物生成常数.制备并考察了以双(N-乙基-N-苯基氨基二硫代甲酸)1,3-丙二醇酯为载体的银离子选择电极的性能.实验结果表明:该选择电极对银离子有良好的响应性能和高选择性,在10-3~10-6mol/L的浓度范围内响应斜率为56.0 mV/paAg+,检测下限为3.7×10-7mol/L,碱金属、碱土金属及过渡金属离子不干扰银的测定.该电极可作为测定维生素B1药片中维生素B1含量的电位滴定指示电极和水样中银离子含量的直接测定.

Preparation and Application of a PVC Membrane Ag(I) Ion Selective Electrode

Trimethylene bis(N-ethyl-N-phenyldithiocarbamate) was used as the ionophore in solvent polymeric membrane.The ionophore-metal ion complex formation constants in solvent polymeric membrane were determined directly by potentiometry with a two-layer membrane electrode.A silver ion selective electrode was prepared and characterized with trimethylene bis(N-ethyl-N-phenyldithiocarbamate) as ionophore.The membrane electrode exhibited a good response to silver(I) with a slope of 56.0 mV/pa_(Ag~+) in the concentration range 10~(-3)~10~(-6) mol/L AgNO_3 solution,and the detection limit is(3.7×10~(-7) mol/L).The electrode has a highly selectivity for silver ion over alkali,alkaline earth and common transition metal(ions).The electrode was used as the indicator electrode in titration of halide ions and Vitamin B_1 in Vitamin B_1 tablets with silver ion.The proposed electrode has also been used for the direct determination of silver ion in water sample.