ICP-MS Determination of 12 Heavy Metal Elements in Cereals with Microwave Assisted Sample Digestion

The sample of cereals was digested with HNO3 and H2O2 in a microwave digestion system, and the contents of 12 heavy metals (i.e. As, Pb, Cd, Se, Cr, Tl, Mn, Ni, Cu, U, Co and V) in the sample solution were determined by ICP-MS. The interferences of the matrix elements were eliminated by internal standard. Detection limits (3S/N) of the method found were in the range of 0.092-17.5 pg·g-1. Tests for recovery were made by standard addition method, giving values of recovery in the range of 88.1%-118% with RSD′s (n=5) less than 6.0%. In the analysis of CRM of chicken (GBW 10018) by the proposed method, the results obtained were in consistency with the certified values.