锑(Ⅲ)-高铁试剂络合物吸附波的研究

Study on the Complex Adsorptive Wave of Antimony(Ⅲ)-7 Iodo-hydroxyquinoline-5-sulphonic Acid

在 pH4.4的 HAc-NaAc 介质中,锑与高铁试剂生成络合物,于-0.59V(vs.SCE)出现一尖锐灵敏的极谱波。峰电流与锑(Ⅲ)浓度在3.3×10^(-8)～3.3×10^(-6)mol/L 范围内呈线性关系。检出限为1.6×10^(-8)mol/L.络合物组成为 Sb(Ⅲ):Ferron=1:2。以巯基棉分离干扰离子,用标样对方法进行验证,结果满意。

In the medium of HAc-NaAc at pH 4.40,antimony(Ⅲ)formed a complex with 7-iodo-hydroxyquinoline- 5-sulphonic acid(Ferron),which caused a sharp adsorptive wave at -0.59V(vs.SCE).The height peak of current is propor- tional to the concentration of antimony(Ⅲ)in the range of 3.3×10^(-8)-3.3×10^(-6)mol/L.Effects of more than 30 ions have been tested.Several electrochemical methods have been used to investigate the elecrtrode reaction mechanism and proved as fol- lowing:the complex is in negative charge,the electroactive species is antimony(Ⅲ)in the complex,and the molar ratio of antimony(Ⅲ)to Ferron in the complex is 1:2.The method has been successfully applied to the determination of antimony in a standard mineral sample with prior separation using hydrosulfuryl cotton fiber.