镉超高灵敏显色反应的研究

A Study on High Sensitive Color Reaction of Cadmium

本文研究了高灵敏测定镉的光度法,在阿拉伯胶存在下,在0.02—0.16mol/L硫酸介质中,镉与碘化物和罗丹明6G生成离子缔合物。该缔合物最大吸收波长为525mn,表观摩尔吸收系数ε_(525)为1.6×10~6L·mo1^(-1)·cm^(-1),镉浓度在0—2μg/25ml符合比耳定律。考察了共存离子的干扰影响,该法可用于测定水中痕量镉。

A high sensitive spectropphtometry of cadmium is studied in this paper. In the presence of gum acacia, cadmium reacts with iodide and rhodamine 6G to form an ion--asso- ciation complex in 0. 02--0. 16 mol/L H_2SO_4 medium. The ion-association complex shows a wave lenqth of absorption peak at 525 nm and an apparent molar absorbance index ε_(525)= 1. 6 ×10~6L. mol^(-1). cm^(-1). Beer's law is obeyed by 0--2. 0μg/25ml cadmium. The interference from coexisting ions is inspected. The method can be applied t_o the determination of trace cad- mium in the water.