Application of an in situ Bismuth-coated Glassy Carbon Electrode for Electroanalytical Determination of Cd (II) and Pb (II) in Korean Polished Rices

Rapid on-site monitoring of heavy metals in plants is necessary to minimize the exposure of humans to the contaminated food. The potential of using anodic stripping voltammetry (ASV) for simultaneous determination of cadimium (Cd) and lead (Pb) in rice was evaluated. Eight different Korean polished rices were digested using concentrated HNO3 solution in a microwave oven. The peak currents measured with an in situ bismuth-coated electrode were linearly proportional to Cd and Pb concentrations (1.5 to 200 ppb) in 0.1 M HNO3 (R-2 >= 0.98). The electrode was feasible for measuring Pb in acid digests of the tested polished rices with measurement errors of <16.3 ppb. However, even though there was acceptable agreement in 4 of the 8 samples tested for Cd between the ASV and inductively coupled argon plasma (ICP) methods, further studies would be needed to improve the predictive capability of the electrode while reducing the variability in measurement and lowering the detection limit,