Derivative spectrophotometry for determination of zinc(II) and cadmium(II) using diphenylcarbazone in presence of Triton X-100

Diphenylcarbazone has been used for the simultaneous and individual determination of zinc(II) and cadmium(II) at trace levels. The carbazone complexes of zinc(II) and cadmium(II) at pH 7-10 are pink in color, and are soluble in TX-100 micellar media. Under optimum conditions, calibration graphs for individual and simultaneous determination by first, second, third and fourth derivative spectrophotometry has been obtained. A zero crossing method using fourth derivative at 493.5 nm and 448.5 nm has been used for simultaneous determination of Zn(II) and Cd(II) respectively. To investigate the selectivity of the method, the effects of diverse ions on the determination of zinc and cadmium have also been studied. The recommended procedure has been applied to synthetic binary alloys and pharmaceutical samples.