Simultaneous voltammetric determination of trace bismuth(III) and cadmium(II) in water samples by adsorptive stripping voltammetry in the presence of cupferron

Simultaneous adsorptive stripping voltammetric method for the determination of trace bismuth(III) and cadmium(II) using cupferron as a complexing agent has been optimized. Experimental conditions under which these elements can be simultaneously detected have been established. The optimized conditions include: 0.1 mol L−1 acetate buffer (pH = 5.3), 1 × 10−3 mol L−1 cupferron, accumulation potential −0.4 V, accumulation time 30 s. The calibration graph was linear from 2 × 10−9 mol L−1 to 2 × 10−7 mol L−1 with the correlation coefficient of 0.9984 for bismuth and from 2.5 × 10−9 mol L−1 to 2 × 10−7 mol L−1 with the correlation coefficient of 0.9987 for cadmium. The detection limits for preconcentration time of 30 s were 9.8 × 10−10 mol L−1 and 1.0 × 10−9 mol L−1 for bismuth and cadmium, respectively. The application of this method was tested by simultaneous recovery of Bi(III) and Cd(II) from spiked water samples. The negative influence of the organic matrix present in environmental water samples due to their adsorption on Amberlite XAD-16 resin was successfully evaluated.