SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF CADMIUM, COPPER AND ZINC

A method for the simultaneous spectrophotometric determination of cadm ium, copper and zinc based on the formation of their complexes with 1, 5-bis(di-2-pyridylmethylene)thiocarbonohydrazide is proposed. The abso rption curves of these complexes overlap severely in the scanning rang e 380-480 nm. The analyte concentrations are calculated by a least squ ares fit of the pure spectra to the mixture spectra. A linear determin ation range of 0.1-1.7 mug/ml for cadmium, 0.1-1.3 mug/ml for copper a nd 0.2-1.2 mug/ml for zinc were obtained. The effect of interference w as studied. The method has been applied to the determination of these metal ions in various type of materials.