Studies on monoxide emission spectrometry of rare-earth elements. IV. Simultaneous determination of Sm, Eu, Gd in Sm---Eu---Gd concentrates by the dual wavelength method

This paper reports the determination of samarium, europium and gadolinium by Sm and Gd monoxide emission and Eu atomic emission. The enhancement effect of other rare earth elements on Sm, Eu and Gd emission was studied. Large amounts of lanthanum (La) were used as enhancing reagents and chemical interference inhibitors and the dual wavelength method was introduced to eliminate spectral interference, in which the analytical wavelengths used were Sm 651.0 nm, Eu 459.4 nm and Gd 461.6 nm and the reference wavelengths were Sm 651.4 nm, Eu 459.8 nm and Gd 461.2 nm. The method has been applied to the assay of Sm, Eu and Gd in synthetic Sm---Eu---Gd concentrates with satisfactory results.