[A primary study on chemical bound forms of copper and zinc in wheat and rape]

Sequential extraction method was used to analyze and distinguish various chemical bound forms of copper and zinc in rape and wheat. The results show that in these two crops, copper was mainly in the form of wate soluble and ethanol soluble, which can be easily transferred in crops. The total content of various chemical bound forms of copper was higher in aboveground part than in underground part, and their content was decreased in the order of water soluble form (W.S. form) > residual form (Re. form) > ethanol soluble form(Eth. S. form) > acid soluble form (A.S. form). Zinc was mainly in the form of acid soluble, which is hard to be transferred in crops. The total content of various chemical bound forms of zinc was lower in aboveground part than in roots, and their content was decreased in the order of A.S. form > Re. form > W.S. form > Eth. S. form. In comparing with copper, a large amount of zinc was enriched in seeds and pods of rape.