In a recent paper [1] the hydrolysis and carbonate complexation of Eu(III) was studied by potentiometric titration of 2×10-4 M Eu(III) solutions in the range pH = 7-13. Under the experimental conditions applied in this study, the Eu(III) concentration exceeds the solubility of Eu(OH)3(s) or EuOHCO3(s) by several orders of magnitude. The formation constants derived for numerous aqueous Eu(III) hydrolysis species and ternay hydroxo-carbonate complexes must be considered as erroneous. They are the result of misinterpretation of the formation of solid Eu(III) particles as hydrolysis or carbonate complexation in solution.
Print ISSN: 0033-8230
Volume: 88, 08/2000
Pages: 499