Determination of trace amounts of' rare earth elements in high pure lanthanum oxide by sector field inductively coupled plasma mass spectrometry (HR ICP-MS) and high-performance liquid chromatography (HPLC) techniques

An analytical method for the determination of traces of rare earth elements (REE) as impurities in high pure lanthanum oxide (La2O3) produced in the Instituto de Pesquisas Energeticas e Nucleates (IPEN) and compared with the oxide of commercial lanthanum as a certified reference is discussed in this work. The REE as impurities in the lanthanum oxide were separated from the matrix by a high-performance liquid chromatography (HPLC) technique. The separated individual fractions containing the REE trace impurities were analyzed directly by inductively coupled plasma sector field mass spectrometer (HR ICP-MS) (Element, Finnigan MAT). The percentage recovery ranged from 88 to 100 for different rare earth elements. The mean R.S.D. of the method varying between 2 and 5% for a set of five (n = 5) replicates was found for the IPEN's material and for the certificate reference sample. In short, it can be claimed that both materials are highly pure (>99.9%). (C) 2002 Elsevier Science B.V. All rights reserved.