Potentiometric Stripping Analysis of Zinc, Cadmium and Lead in Tobacco Leaves (Nicotiana Tabacum L.) and Soil Samples

The potentiometric stripping analysis (PSA) with oxygen as the oxidant has been used to determine total zinc, cadmium and lead levels in tobacco leaves (Nicotiana tabacum L.), agricultural soil and cigarettes. The content of these metals in the leaves of the analyzed tobacco cultivars (Virginia, Burley and Oriental), obtained from locations which were close to industrial facilities and main roads, was higher than in the tobacco which was grown in rural areas. In addition to the cited potential sources of Zn, Cd and Pb, what also has an effect on the content of these metals in the studied samples of tobacco leaves is the soil in which the tobacco plant is cultivated. Thus the content of zinc in the tobacco leaves of all the studied tobacco plant types was approximately five times, of cadmium was approximately two times and lead approximately three times smaller than the content in the soil samples taken from the studied areas. The total content of heavy metals in fine brand of cigarettes was lower than in popular brand of cigarettes. The results of this work suggest that PSA may be a good method for zinc, cadmium and lead determination in soil, tobacco leaves as well as in different plant species.