锌—DMTAM显色反应的分光光度法研究

Spectrophotometric Study of the Color Reaction of Zinc With 2-(4,5-Dimethyl-2-Thiazy-lazo)-5-Dime thylaminophenol (DMTAM)

本文在研究新试剂2—(4,5—二甲基—2—噻唑偶氮)—5—二甲氨基酚(记作DMTAM)与镍及钯的显色反应基础上,继续研究了该分析试剂与锌的显色性能。结果表明,在pH8.0～9.5氨性介质中,Zn(Ⅱ)与DMTAM形成稳定的红紫色配合物,其最大吸收波长为580nm,表观摩尔吸光系数为8.42×10~4L·mol^(-1)·cm^(-1),锌与DMTAM的组成比为1∶2,线性范围为0～12μgZn(Ⅱ)/25mL。方法灵敏度高,操作简便,并应用于铝合金及矿样中微量锌的测定。

A simple and sensitive method for the spectrophotometric determination of trace zinc has been developed. Zinc reacts with DMTAM in the presence of 30 per cent of ethyl alcohol. The optimum range of pH is 8.0 to 9.5.The moar ratio (Zn(II):DMTAM) is estimated to be 1:2. The complex has a maximum absorption at 580nm, and its molar absorptivity is 8.42×10~4Lmol^(-1)cm^(?) Beer's law is obeyed in the range of 0～12μg of Zn(II)per 25 mL. The method has quite high sensitivity and selectivity, and has been applied to the determination of trace zinc in ores and aluminium alloy with satisfactory results.