Abstract
A method for the determination of Pb, Cu and Se in tobacco samples by anodic stripping voltammetry has been developed. Pb, Cu and Se were determined in Turkish and American cigarettes using a mercury film graphite electrode, by digesting the tobacco sample in acid or acid mixtures following extraction with 1-butanol. The appropriate results for Pb, Cu and Se were obtained from the digestion mixtures of HNO3-HclO4 (1/1) for Pb, HNO3-HClO4-H2SO4 (2/2/1) for Cu and Se. Interference due to the large amount of Cu was reduced to the proper level by 1-butanol extraction, that made the determination of Se possible. The effects of deposition potentials, deposition times and pH of the medium have been discussed. The applied deposition potentials for Pb, Cu and Se were -850, -600 and -400mV (vs. Ag/AgCl) respectively. The peak potentials in HClO4 solution (pH≅2) were -350mV for Pb, -20mV for Cu and +60mV for Se. The relative standard deviations are 4.5% at the concentrations of 2.2ppm Pb (n=5) and 4.4ppm Cu (n=6), and 8.3% at 0.12ppm Se(IV) (n=8).
