ICP-MS Determination of Cu, Zn, Cd, Ni and Pb in Wheat with Microwave Assisted Sample Digestion

Sample of wheat was digested with a mixture of HNO3 and H2O2 in a microwave sample digester under programmed temperature control. The contents of Cu, Zn, Cd, Ni and Pb in the sample solution were determined by ICP-MS with using Rh as internal standard. Isobaric interferences were overcome by the interference correction formula. Values of detection limit (3s) of the method were found in the range of 0.005-0.062 μg·g-1. In the analysis of a CRM (GBW 10011) by this method, results obtained were in consistency with the certified values, with RSD′s (n=9) in the range of 1.9%-8.4%.