ICP-MS Determination of Cu,As,Cd,Hg and Pb in Giant Knotweed

The sample of the Chinese traditional medicine giant knotweed was pretreated by microwave assisted digestion,and determined by ICP-MS.Working parameters of the ICP-MS instrument were optimized,and 6Li,45Sc,72Ge,115In and 209Bi were used as internal standard.Linear relationships of the 5 elements were kept in definite ranges,with detection limits (3S/N) in the range of 0.013-0.120 μg·L-1.Values of recovery and RSD′s (n=5) found were 103.4% and 1.14% for Cu,100.2% and 0.55% for Pb,104.6% and 1.82% for Cd,89.7% and 1.91% for Hg,92.9% and 1.40% for As,respectively.