Application of Wall Stabilized Plasma Arc to Optical Atomic Emission Spectrometry of Lanthanoides, Yttrium and Scandium after Separation with Cellulose Ion-Exchanger

The use of a cellulose ion-exchanger (Hyphan) for the isolation of the rare earth elements (REE′s) yttrium and scandium from aqueous solution is described. After preconcentration, the cations under investigation were determined using a wall stabilized plasma arc in atomic emission spectroscopy (DCP-OAES). The detection limits for Sc, Y, La, Nd, Gd, Yb and Lu were determined (0.02-0.31μg ml-1). The distribution coefficient for the investigated cations were determined as a function of pH. The order of selectivity is the following sequences, Yb>Lu>Gd>Y>La>Sc>Nd at pH of 7.15-9.04. The distribution coefficient obtained is in the range 102-105ml/g. Such order of selectivity was also confirmed by thermal analysis technique. Moreover, the lanthanoid complexes formed by the chelating ion exchanger were characterized by reflectance and infrared spectrometry. Alkali and alkaline earth cations did not interfere at 50-100μg ml-1.