Spectrographic determination of Nd, Sm, Gd, Tb and Dy in high purity europium oxide

Nd, Sm, Gd, Tb and Dy have been determined spectrographically in europium oxide of high purity within the concentration range of 0.005 to 0.1%. The sample is mixed with graphite powder in the ratio 1∶1 and amounts of 10 mg are excited in the 15 A d.c. arc for 25 sec. The spectra were recorded with a 3.4 m Jarrell-Ash grating spectrograph with a reciprocal linear dispersion of 1.2 A/mm. Eu 3649.8 and Eu 4064.5 were employed as internal standard lines. The variation coefficient was between 10 and 18%.