Simultaneous assessment of zinc, cadmium, lead and copper in poultry feeds by differential pulse anodic stripping voltammetry

In the present work four metals (Zn, Cd, Pb and Cu) were determined simultaneously in 28 commercial broiler poultry feeds by differential pulse anodic stripping voltammetry (DPASV) using hanging mercury drop electrode (HMDE). The digestion of poultry feeds was carried out with concentrated nitric acid and hydrogen peroxide (2:1) with the help of microwave heating. Acetate buffer of pH 5 was used as a supporting electrolyte. The limit of detection for Zn, Cd, Pb and Cu was 0.69, 0.35, 0.68 and 0.24 μg/kg, respectively. The amount of Zn, Cd, Pb and Cu in the analyzed poultry feeds was ranged between 54.3–482.2, 3.8–33.6, 23.2–32.6 and 12.3–65.8 mg/kg, respectively. In most of analyzed poultry feed samples, the amount of Cd and Pb was found to be greater than the maximum tolerable level (MTL) which could be harmful for the poultry.