The Quantitative Spectrographic Analysis of the Rare Earth Elements*I Determination of Samarium in NeodymiumII Determination of Europium in Samarium

Spectrographic methods applicable to the determination of small amounts of rare earth impurities in other rare earths are described. The specific examples discussed are the determination of samarium in neodymium and of europium in samarium. The procedures involve the high current d.c. arc excitation of rare earth oxide-graphite mixtures. Selected lines of the major rare earth constituent are used as internal standards. The experimental error of these methods is about 4 percent. Studies on the variation of the analytical intensity ratio during excitation and the effect of large changes in arc current, percent graphite, and weight of sample charge on the intensity ratio values are included.