Solvent extraction separation of heavy rare earth elements from light rare earth elements and thorium: ICP-AES determination of REEs and yttrium in monazite mineral

摘要

An accurate and direct ICP-AES determination of low-level heavy rare earth elements (HREEs) in Indian monazite mineral is difficult due to spectral interferences and also due to changes in the plasma excitation conditions in the presence of very high amounts of light rare earth elements (LREEs) and thorium. A solvent extraction procedure for the separation of HREEs from LREEs and Th in monazite mineral is described for interference-free ICP-AES determinations. The REE, Y, and Th content in the monazite is prepared in either 0.1M or 0.2M HCl and the HREEs are selectively separated from LREEs and Th using 0.22M bis-(2-ethyl hexyl) hydrogen phosphate (HDEHP).