Spectrophotometric determination of trace amount of copper(II) ion based on the complexation with an anthraquinone derivative

Department of Chemistry, Faculty of Sciences, Zabol University, Zabol, P.O. Box 98615-538, Iran

Manuscript received 9 December 2005, accepted 3 March 2006

The spectrophotometric determination of Cu^II with an anthraquinone derivative (Alizarin Red S) has been investigated. Experimental conditions such as the pH of the sample and concentration of ligand were optimized. This method is a simple and sensitive method for determination of Cull ion. The interfering effects of diverse ions were investigated. Copper ion was determined by measuring the absorbance of Cu^II-ARS complex at 510 nm. Beer's law is obeyed over the concentration range of 0.011-0.320 mM and the detection limit (S/N = 3) is 0.038 ppm. The relative standard deviation at the 20 ppm is 1.02% (N = 5). The method was applied for the real samples.