use of differential pulse cathodic adsorptive stripping voltammetric method for the simultaneous determination of trace amounts of cadmium and zinc

a selective and sensitive method for determination of cadmium and zinc is presented. the method is based on adsorptive accumulation of the complexes of cd (ii) and zn (ii) ions with 4-amiono-5-methyl-2,4-dihydro-3h-1,2,4-triazol-3-tion (mmtt) onto hanging mercury drop electrode (hmde), followed by reduction of the adsorbed species by voltammetric scan using differential pulse modulation. the ligand concentration, ph, potential and time of accumulation, scan rate and pulse height were optimized. under the optimized conditions, a linear calibration curve was obtained for the concentration of cd (ii) and zn (ii) in the range of 5-450 and 5-850 ng/ml, respectively, with a detection limit of 1.7 ng/ml cd (ii) and 1.3 ng/ml zn (ii). the ability of the method was evaluated by analysis of cadmium and zinc in water and alloy samples.