Speciation of Rare Earth Elements in Soil by HPLC-ICP-MS

Elemental speciation is one of the growing features of analytical chemistry of recent two decades. It is now widely recognized that the determination of total trace element contents is no longer sufficient for evaluating their pathways,environmental and biological effects, which mainly depend on their specific chemical forms existing in the samples. On the other hand, rare-earth elements (REEs), which have their unique properties, have recently been used in many fields of industry, and agriculture especially in China for increasing the crop's production. Up to now, the amount of REEs used in agriculture is more than 1000 tons per year in China.¹Such a great amount of "foreign" REEs is annually applied to the environments, what is the effect of the "foreign" REEs to the environments except the increase production brought? Moreover, how is the biological effect to living things including human beings after eating the food? To answer such questions, the speciation of REEs has a special significance.