End-on viewed inductively coupled plasma for the determination of trace impurities in high-purity scandium oxide by extraction chromatography

Abstract

A sensitive method is described for the simultaneous determination of eighteen trace impurities in high-purity scandium oxide using an end-on viewed inductively coupled plasma (ICP) combined with an aerosol desolvation apparatus after the separation and preconcentration of the impurities. The operating conditions of the end-on viewed ICP were optimized and possible interferences caused by the matrix scandium in the end-on viewed plasma were studied. The chromatographic separation of trace amounts of impurities from large amounts of scandium, prior to the ICP atomic emission spectrometric (AES) measurements, using a trioctylphosphine oxide-Levextrel resin column was investigated. Satisfactory recoveries were obtained for impurities added to Specpure-grade scandium oxide, with average recoveries of 94–111% and precisions of better than 10% for most of the elements. The practical limits for determination were 0.08 (Mn)−4 μg g −1 (Zn) for 0.1 g of sample. The results obtained for a high-purity scandium oxide sample by the proposed method agreed very well with those obtained by other techniques. The proposed separation procedure and the end-on viewed ICP-AES method are shown to have several advantages.