Application of Stripping Voltammetry for the Determination of Cadmium, Lead, Copper and Zinc in Yemani soils and Vegetables

Abstract

Heavy metals contents in the solutions from acid digestion of Yemeni soils and vegetables were deter¬mined by differential pulsed anodic stripping voltammetry. The geometric mean for Cd, Pb, Cu and Zn concentrations for the soils (to a depth of 40 cm) were 0.56, 9.4, 35 and 58 mg kg"1 dry weight respec¬tively. These levels are closely related to the literature values for uncontaminated soils. Highest and low¬est concentrations of Cd were in watercress and cucumber (37.6 and 2.6|j.g kg"1, resp.); Pb in watercress and tomato (306.8 and 30.2^ig kg"1, resp.); Cu in Jew's marrow and cabbage (4734 and 521^g kg1, resp.); and Zn in Jew's marrow and tomato (5561 and 559^,g kg"1, resp.). These values do not pose a health risk for consumers, according to the levels proposed by FAO / WHO.