The effect of various acids on the atomic absorption of rare earths

Abstract

The effects of hydrochloric, sulphuric, nitric and perchloric acids on the atomic absorption of the rare earth elements yttrium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium and ytterbium have been determined. The rare earths can be categorised into two groups according to their behaviour in the four acids. Elements in group I (samarium, europium, dysprosium, holmium, erbium, thulium and ytterbium) showed little change in absorption behaviour in these acids, and no change when the acid concentration was varied from 0·1 to 0·5 M. Yttrium, gadolinium and terbium of group II are sensitive to the type of acid used. Considerable suppression of absorption was caused by sulphuric acid and less severe suppression by nitric acid. The suppression caused by sulphate and nitrate cannot be eliminated with enhancing agents, and these anions should be removed when the above elements are determined. The elements in group II can be determined in 0·1 to 0·5 M hydrochloric or perchloric acid.