Effects of exogenous addition of cadmium on cadmium speciation in hyperaccumulator of Sedum alfredii Hance

Abstract

Continuous chemical extraction is considered to be one of the most common methods for the extraction of heavy metals speciations in plants. However, the basis for the extraction order of this method is not explained and has been rarely studied. In this paper, we analyzed the speciations of cadmium in plants by a four-step continuous extraction method. The extraction sequence of ethanol and water was studied to study the effect of extraction sequence on the extraction rate of extraction agent. The results showed that cadmium exists mostly in NaCl extraction state and the extraction rate of the two kinds of extraction agents decreased when the order of ethanol and water was changed.