ICP-MS Determination of As, Cd, Cr and Pb in Chinese Cabbage with Microwave Assisted Sample Digestion

The sample of Chinese cabbage was digested with HNO3 and H2O2 in MARS X PRESS microwave digestor, and 4 elements, i.e., As, Cd, Cr and Pb in the solution were determined by ICP-MS. The MS interferences were eliminated by selecting the istopes 75As, 111Cd, 52Cr and 208Pb. Under the optimized conditions, values of detection limit (3σ) of the method found were 0.08 μg·L-1 for As, 0.03 μg·L-1 for Cd, 0.26 μg·L-1 for Cr and 0.02 μg·L-1 for Pb. The proposed method was applied to the analysis of Chinese cabbage, giving values of recovery found by standard addition method ranged from 82% to 104% and RSD′s (n=5) ranged from 2.8% to 6.3%.