南河底泥中微量镉的催化极谱测定

Catalytic Polarographic Determination for Micro Cadmium in Sediment of Nanhe River

本文提出了一种新的碘化钾—苯并—15—冠—5—镉络合体系作基质,以极谱催化波测定痕量镉。峰电位在—0.8伏左右,检测限为2ppb,镉浓度与峰高在4—100ppb范围内呈线性关系。方法简单快速,且选择性好。镉浓度在7.5ppb,变异系数为2.6％,回收率为97.5—110％,用该法与常规AAS法对成都南河底泥中微量镉进行对比分析,获得了同样准确的结果。

For determining trace Cadmium by using a polarographic catalytic wave, this paper proposes a new KI-Benzo-15-Crown-5-Cd complex system as a base solution. The peak potential is-0.8V(vs. SCE). The limit of detection for Cadmium is 2ppb. The linear relationship is held between peak height and Cadmium concentrtion ranging from 4-100ppb. This method is rather simple and rapid and of high selectivity. At the Cadmium conentration of 7.5ppb, the coefficient of variation is 2.6％, recoveries 97.5-110％. In comparison with the conventional AAS, this method has almost the same accuracy for the determination of micro Cadmium in sediment of Nanhe River, Chengdu.