A highly sensitive method for simultaneous determination of ultra trace levels of copper and cadmium in food and water samples with luminol as a chelating agent by adsorptive stripping voltammetry

In the present study a selective method is presented for the simultaneous determination of copper and cadmium in food samples by adsorptive stripping voltammetry. In preliminary studies, it has been proven that the copper and cadmium react with 3-aminophthalhydrazide (luminol), giving rise to the formation of these complexes. These complexes have adsorptive characteristics on hanging mercury drop electrode (HMDE) and can be reduced in a reduction step. In this study the optimum reaction parameters and conditions studies are investigated. The calibration graphs were linear in the concentration range of 0.5–105.0 and 0.8–70.0 ng/ml for copper and cadmium, respectively. The limit of detection of the method was 0.04 ng/ml for Cu2+ and 0.02 ng/ml for Cd2+. The interference of some common ions was studied and it was concluded that application of this method for the determination of copper (II) and cadmium in food and water samples led to satisfactory results.