Chemical Species and Distribution of Heavy Metal Elements in Erigeron Breviscapus

FAAS (for determination of Pb,Cr and Cd) and AFS (for determination of Hg and As) were used in the study of chemical species and distribution of the 5 metal elements in the traditional chinese medicine,erigeron breviscapus (EGR-BVCP).0.5 g of the pretreated EGR-BVCP sample was digested with conc.HNO3 and fumed with HClO4 to near dryness.The salts were dissolved and diluted to 25 mL with water,and the solution was used for determination of total amount of the 5 metal elements.For separation of different chemical species of these metal elements,successive ultrasonic extractions of a 10 g portion of the sample were performed by using 5 different extractants,i.e.,ethanol-H2O(80+20) mixture,sub-boiling re-distilled water,1 mol·L-1 NaCl solution,acetic acid (2+98) solution and 0.6 mol·L-1 HCl succeedingly.The extracts obtained in each extraction was treated with HNO3 and HClO4 as described above and the contents of the 5 metal elements,were determined by the same methods.Data of amount of the metal elements in various chemical species were given in detail,which are valuable for evaluation of biological function and toxicity of the traditional Chinese medicines.