TADMA分光光度法测定微量铜的研究及应用

Colour Reaction of 4-(2-thiazolylazo)-5-dimethylamino-aniline with Cu(Ⅱ) and Its Application

研究了显色剂4-(2-噻唑偶氮)-5-二甲氨基苯胺(简称TADMA)与铜(Ⅱ)的显色反应。实验表明,在pH=3.20～5.10HAc-NaAc缓冲介质中,TADMA与铜(Ⅱ)反应生成2:1红色配合物,配合物的表观摩尔吸光系数为6.65×104L·mol-1·cm-1,铜(Ⅱ)浓度在0～0.42μg/mL范围内服从比耳定律。本方法操作简便,灵敏度高,选择性好,可直接用于铝合金和纯铝中微量铜的测定。

The colour reaction between Cu(Ⅱ) and 4-(2-thiazolylazo)-5-dimethylamino-aniline (TADMA) was studied. The experimental results show that Cu(Ⅱ) reacts with TADMA at pH3.20~5.10 to form a red complex. Its apparent molor absorptivity is 6.65×104L·mol -1 ·cm -1 . Beer’s law was obeyed in the concentration range of 0~0.42μg·mL -1 for Cu(Ⅱ) at 578nm. The molor ratio of Cu(Ⅱ) to TADMA is 1:2 in the complex. The method has more sensitivity and selecttivity. It has been applied to the determination of Al-alloy and pure -Al with satisfactory results.