Essential and toxic trace elements in the Chinese medicine

The concentration of certain toxic and essential elements in various raw materials of Chinese herbs and 'scientific Chinese medicine' were determined by atomic absorption spectrometry (AAS) and instrumental neutron activation analysis (INAA). Correlation of these elements as they exist in the raw materials and in the prescription of medicine were investigated and the approximate intake of elements by patients were estimated. Values of elements determined both by AAS and INAA presented excellent agreement. The ranges of elemental concentrations were found to vary from 104 to 10-1 mg/kg in different kinds of herbs. All herbs exhibit extraordinary enrichment capabilities from the environment for elements such as Mn, Zn, Ca, K, Mg, Cd, Cu, Pb and As. Higher contents of Cd, Pb and As in herbs may be attributed to the uptake of these elements from polluted soil due to industrial and antropogenic activities. It was found that commercial scientific Chinese medicine, SCDBT, contains more elemental concentrations than that of herbs used in the prescription, which may indicate that possible contamination could be caused by unknown ingredients added in process. A much higher toxic elemental content, such as Pb, Cd and As, has been found in CFH and the daily intake of these elements by the patient will exceed the PTDI values.