Lanthanide and actinide sulfate complexes—I: Determination of stability constants

Abstract

The stability constants of the complexes of yttrium and the lanthanide ions (except Pm) with sulfate were determined using a competitive potentiometric method at μ = 2·00 M (NaClO 4), pH = 3·0 and t = 25·0°C. A solvent extraction technique was used to measure stability constants of the sulfate complexes of Ce(III), Pm(III), Eu(III), Am(III), Cm(III) and Cf(III) with the same set of conditions. With these conditions there is evidence of formation of M(SO 4) + and M(SO 4) 2 −. The values of β 1 ranged from 12 to 27, while those of β 2 varied from 39 to 117.