[Contents and solubilties of several elements in siwu decoction and liuwei dihuang decoction]

In this paper the contents and solubilities of copper, zinc, iron, calcium and magnesium in Siwu decoction and Liuwei Dihuang Decoction were studied. The results showed that there was a big difference in the solubilities of the elements among the crude drugs, and the increased solubilities of some elements in the simple recipe and compound prescription were an important factor for the effect of these decoctions. The increased solubilities of some elements might be one of the advantages for the compound prescription.