Analysis of a rare-earth sample, Didym by ion chromatography/neutron activation analysis and isotachophoresis/particle induced X-ray emission method

In the history of the discovery of rare-earth elements, two elements, Pr and Nd were isolated by Brauner (1882) from a rare-earth sample (Didym) which was considered to be mono-element and their atomic numbers were also determined. In this study, the oxide sample employed in the separation processes was analyzed using two coupled analytical methods, ion chromatography/neutron activation analysis (IC/NAA) and isotachophoresis/particle induced X-ray emission method (ITP/PIXE). Four rare-earth elements were only determined by NAA of 40μg of Digym. Whereas for IC/NAA with preseparation process, 13 rare-earth elements containing 0.004mass % Yb were determined when 100 μg of Didym was analyzed. For ITP/PIXE, 12 rare-earth elements were determined. The results obtained by the coupled analytical methods agreed with each other. Although the content of Ce in the sample (Didym) obtained from Cerite was very small, that of La was large, suggesting that chemical treatments to remove La had not been achieved. (author)