新试剂氨替比林基重氮氨基偶氮苯与镉的显色反应研究及其应用

The Colour Reaction of Cadmium With New Reagent Antipyrinyldiazoaminoazobenzene and Its Application

在 Tween-80存在下,pH10.5～12.0时,新试剂 Cadion AP 与镉(Ⅱ)生成红色配合物,其最大吸收波长为530nm,试剂的最大吸收波长为402nm,配合物的组成为1:2;表观摩尔吸光系数为2.11×10~5l·(mol·cm)^(-1);0～18μg(Cd)/25ml 符合比耳定律。在混合掩蔽剂存在下,直接测定了地面水中的镉;以萃取分离法测定了人发及碱式氯化铝中的镉。标准加入回收率为98～109%,方法的标准偏差为0.19,相对标准偏差为3.4%。

The optimum condition of the color reaction on cadmium with new reagent, antipyrinyldiazoaminoazobenzene(Cadion AP),was studied.In the presence of Tween-80, Cd(Ⅱ)reacts with Cadion AP to form a red complex,the molar ratio of Cd(Ⅱ)to Cadion AP is 1:2.The molar absorptivity is 2.11×10~5L.mol^(-1).cm^(-1)at 530nm at pH10.～12.0. Beer’s law is obeyed for Cd(Ⅱ)in the range of 0～18μg/25ml.The method proposed is applied to the direct determination of trace cadmium in the natural water in the presence of mix-screened reagent,sulfocarbamide,triothanolamine,sodium thiosulfate,sodium pota- ssium tartrate,and is appled also to the determination of trace cadmium in human hair and basic aluminium chloride after having been carried out extraction separation.The rela- tive standard deviation(σ=6)is less than 3.4% and the recovery for the added standard cadmium reaches 98～109%.