Influence of silicate ions on Eu(III) aqueous speciation

Interactions of Eu(III) with silicate anions were investigated in undersaturated silica solutions from pH 2 to 7 by time-resolved laser-induced fluorescence spectroscopy (TRLFS) and electrospray ionisation mass spectrometry (ESI-MS). Although silicate is expected to be mostly monomeric, the presence of silica oligomers was observed in some experimental conditions, which may significantly affect the speciation of trivalent metal ions in environmentally relevant conditions.