间羧基苦胺酸偶氮变色酸与铜的显色反应及铝合金中铜的光度法测定

Study on the color reaction of CuⅡ with m-carboxy-picramazo chromotropic acid and spectrophotometric determination of copper in aluminium alloys

在磷酸介质中 ,Cu 与间羧基苦胺酸偶氮变色酸反应生成络合比为 1∶2的稳定蓝色络合物 ,络合物在 663nm处有最大吸收 ,其摩尔吸光系数为 2 88× 10 4,铜含量在 0～ 2 5 μg/2 5mL遵守比尔定律 ,方法用于铝合金中铜含量的测定 ,铜的标准加入回收率在 95 %～ 10 2 %之间 ,结果满意。

In the medium of phosphoric acid, a stable blue complex of Cu? with m carboxy picramazo chromotropic acid(CPCA) is formed. The maximum absorption is at 663nm and the apparent molar absorptivity is 2.88×10 4L·mol -1 ·cm -1 , the composition of the complex is evaluated to be CPCA∶Cu?=2∶1. Beer's law is obeyed in the concentration range of 1-25μg/25mL of Cu?. This method has been applied to determine copper in aluminium alloys with satisfactory results. the recovery is in the range of 95%～102%.