SIMULTANEOUS DETERMINATION OF ZINC, CADMIUM, TIN, LEAD AND COPPER IN CANNED FOODS BY ANODIC STRIPPING VOLTAMMETRY / 营养学报

ABSTRACT

Simultaneous determination of zinc, cadmium, tin, lead and copper was studied in 0.2-0.3M hydrochloric acid-methanol by 1.5 grade differential anodic stripping voltammetry. A stick silver base mercurial film electrode was used as a working electrode. The peak potential of Zn, Cd, Sn, Pb and Cu was distinctly separated each other being -1.05V, -0.74V -0.55V, -0.44V and -0.25V vs SCE, respectivly, in the above solvent electrolyte.Calibration curves of Cd, Sn, Pb and Cu in range of 20 to 600 ng/ml and Zn in range of 0.2 to 4 ug/ml showed linear relation. Canned foods could be analyzed, by dilution with the supporting electrolyte after digestion of the samples with mixed acid. The juice samples could be analyzed directly without digestion, by simple 5-2000 times dilution with the supporting electrolyte. Coefficient of variation and recovey was 6.7-8.0% and 91.2-107% respectively.