Complex formation of uranium(VI) in periodate solutions

Abstract

Summary The uranyl/periodate system was investigated by Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLIFS), and Capillary Electrophoresis (CE) in 0.1 and 0.05 mol L-1 perchloric solutions at pH 2.6, containing various amounts of periodate anions. The formation of only one complex, UO2IO4 +, was observed for a periodate concentration ranging from 5×10-5 to 10-1 mol L-1. The stability constant of this complex was estimated to be log β 11=1.8±0.2 by TRLIFS (fluorescence titration) and log β 11=2.0±0.2 by CE, for an ionic strength of 10-1 and 5×10-2 mol L-1, respectively. Moreover, the 1:1 stoichiometrical ratio between uranium(VI) and periodate was confirmed by an analysis of the results obtained from the deconvolution of fluorescence spectra.