低检出限聚合物膜镉离子选择性电极的研制及应用

Preparation and application of a polymeric membrane cadmium ion-selective electrode with a low detection limit

基于痕量电位分析原理,研制出了一种新型的聚合物膜镉离子选择性电极。通过优化电极内充液组成及聚合物膜组分,电极在10-8～10-4mol/L镉浓度范围内呈现良好的能斯特响应,响应斜率为24.9 mV/dec.,检出限可达5.9 nmol/L。该电极应用于实际湖水样品中镉含量的检测,结果与ICP-MS法数据较为吻合。

A polymeric membrane ion-selective electrode with lower detection limit has been fabricated for sensitive and selective determination of Cd2＋.The influences of the composition of internal solution and membrane on the response of Cd2＋-selective electrode have been studied.Under the optimized conditions,the proposed electrode exhibits Nernstian responses to Cd2＋ in the concentration range of 10-8~10-4mol/L with a slope of 24.9 mV/dec.,and the detection limit is 5.95 nmol/L.The proposed electrode has been successfully used for the determination of trace Cd2＋ in lake water and the results have agreed well with those obtained by ICP-MS.