HG-AAS Determination of Lead, Cadmium and Mercury in Foodstuffs

A method of sequential flow-injection technique hyphenated with HG-AAS was proposed. The foodstuffs sample was digested with HNO3-HClO4 (4+1) solution, and the contents of Pb, Cd and Hg were determined by HG-AAS with KBH4 as reducing reagent and HCl solution as carrying solution. Linear relationships between values of absorbance and mass concentration of the 3 elements were obtained in definite ranges, with detection limit (3S/N) of 0.20 μg · L-1 for Pb, 0.04 μg · L-1 for Cd and 0.22 μg · L-1 for Hg. The proposed method was applied to the analysis of foodstuffs, values of recovery found by standard addition method were in the range of 94.8%-103.2%, with RSD′s (n=6) less than 3.0%.