Evaluation of Lead (Pb) and Cadmium (Cd) Level in Selected Brands of Wine Using Stripping Voltammetry

This study reports on the determination of the concentrations of lead and cadmium in five samples of wine by stripping voltammetry using glassy carbon as working electrode, Ag/AgCl as reference and platinum as auxiliary electrode. The study was carried out in 0.16 M nitric acid containing 0.05 M potassium nitrate as supporting electrolyte. The accumulation of the metals in the wine samples was carried out at -900 mV for a period of 120 s under a hydrodynamic system and after a quiet time of 30 s, the stripping of the metals was carried out by scanning the potential from -900 mV to 200 mV. Lead was detected in a sample of St. Eves wine at a concentration of 3.9 µg/100 mL while cadmium was detected in Eva Fresh, Romex, and St. Lauren wine samples at concentrations of 9.3 µg/100 mL, 5.0 µg/100 mL, and 3.9 µg/100 mL respectively. The concentration of lead in the St. Eves wine sample (3.9 µg/100 mL) was below the maximum permissible limits of 10 µg/100 mL, while the concentrations of cadmium in Eva Fresh, Romex, and St. Lauren wine samples were above the maximum permissible limits of 1.0 µg/100 mL. The results have shown that caution should be exercised in the consumption of these locally made wines