Quantitative spectrographic analysis of the rare earth elements—IX: Determination of rare earth impurities commonly associated with purified samarium, gadolinium, terbium, and yttrium

Abstract

Emission spectrometric methods are described for the following quantitative determinations: neodymium and gadolinium in samarium; neodymium, samarium, terbium, europium, yttrium, dysprosium and holmium in gadolinium; samarium, gadolinium, terbium, dysprosium, holmium, and erbium in yttrium; and samarium, gadolinium, yttrium and dysprosium in terbium. These methods cover the concentration range from the detection limit up to 1 per cent. The basic method involves the direct-current carbon arc excitation of rare earth oxide-graphite mixtures, utilizing the unique similarity in excitation behavior of many of the rare earths to provide a high degree of internal standardization. The coefficient of variation is less than ±5 per cent in all instances.