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 CuII 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 CuII-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