A highly sensitive spectrophotometric method for the determination of trace copper using azure B as a chromogenic reagent

Abstract

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of trace amounts of copper in tap water, polluted water, human hair and alloys. The proposed method is based on the reaction of copper with potassium iodide in acidic medium to liberate iodine, which bleaches violet color of azure B and the absorbance is measured at 644nm. This decrease in absorbance is directly proportional to copper concentration. Beer’s Law was obeyed in the range 2.0-12.0μg/ml of copper. Molar absorptivity and Sandell’s sensitivity of the method were found to be 1.760 x 10⁵ l /mol/cm and 3.61 x 10-4μg/cm² respectively. The developed method has been successfully applied to the determination of copper in tap water, polluted water, human hair and alloys.