Introduce of Minoxidil as a Very Selective ligand for Ultra Trace Detection of Copper Ion by Adsorptive Stripping Voltammetric Method

A new method is presented, for the determination of copper, based on adsorptive stripping voltammetry of the complex of copper with minoxidil at a hanging mercury drop electrode (HMDE). The most suitable operating conditions and parameters, such as pH, accumulation potential, deposition time, ligand concentration and scan rate, were selected. The calibration graph for copper (II) was linear over the concentration range of 0.5 to 700 nM; the detection limit of the method was 0.09 nM. The interferences of some common ions were studied and the method was found suitable for determination of copper (II) in water and drug samples. Moreover, by using of the proposed method, there is a considerable improvement in the detection limit, linear dynamic range and deposition time, compared to the methods other than adsorptive stripping voltammetry for the determination of copper.