Simultaneous quantification of Cd, Cu, Pb and Zn in Thai fermented food by DPASV with a microwave digestion

A differential pulse anodic stripping voltammetry (DPASV) has been developed for the determination of Cd, Pb, Cu and Zn in the local traditional fermented foods of northeastern Thailand. An optimized reagent mixture for microwave digestion composed of 6 mL of HNO3, 2 mL of H2O2 and 2 mL of HF used in microwave digestion. Detection limits of 1.0, 2.0, 0.5 and 0.5 μg/L for Cd, Cu, Pb and Zn, respectively, were obtained. Percentage recoveries obtained of each metal to the sample solution were in the range of 80.6–112.5. It was found that the content of Cd, Cu, Pb and Zn extracted from the samples were in the range 1.0, 10.36-12.45, 18.50-20.75 and 309.65-335.80 μg/L, respectively. The method was successfully applied to determine Cd, Pb, Cu and Zn in Thai traditional fermented food. The results were in agreement with those of graphite furnace atomic absorption spectrometry (GFAAS).