OBJECTIVETo investigate the state and distribution of Pb, Cd, Hg, As, Cu in Rhei Radix et Rhizoma and Chrysanthemi Flos.

METHODThe samples were prepared by modified Tessier sequential extraction; The elements of Cu, Pb, and Cd in the samples were analyzed by atomic absorption spectrometry (AAS), while Hg, and As were analyzed by atomic fluorescence (AFS).

RESULTCu,Pb,Cd,Hg,As in Chrysanthemi Flos were 12.806, 10.478, 0.436, 0.231, 1.531 mg x kg(-1), respectively. Cu, Pb, Hg in Chrysanthemi Flos mainly existed in residual and organic states; Cd was priority to ion exchange state; the residual state was the main form of As, and ion exchange state and water soluble state also had a large proportion. Cu, Pb, Cd, Hg, As in Rhei Radix et Rhizoma were 10.530, 4.926, 0.478, 0.260, 0.750 mg x kg(-1), respectively. Cu, Pb and Hg of residual state were the highest ratio; Cd and As mainly existed in ion exchange state.

CONCLUSIONThe experiment results showed that sequential extraction can be applied in speciation analysis of the harmful elements of traditional Chinese medicine. The method can speciate the state and distribution of harmful elements and provide the information of harmful elements. It will provide reference to the production of Chinese traditional patent medicine and herb extracts, processing of medicine herbs, the development of new drugs and safety evaluation of traditional Chinese medicine.