摘要：

Complexation studies of radionuclides (such as uranium) are important to perform in order to predict their migration behavior in natural systems. Time-resolved laser-induced fluorescence, which is a very selective and sensitive method for actinide and lanthanide analysis, is used to study the interactions between uranyl cation and hydroxide ions at low uranium concentration (0.4 [mu]M). The principle of the study is based on time resolution and spectral convolution since free uranyl ion (UO[sub 2][sup 2+]) and first hydroxide complex give specific fluorescence spectra characterized by their spectral shift and fluorescence lifetime. Spectroscopic data (main fluorescence wavelengths, half-bandwidth, lifetime) for the first hydrolyzed complex UO[sub 2]OH[sup +] are obtained. From experimental spectra and time-resolved spectral convolution, the proportion of each species (free uranyl, complexed uranyl) can be estimated at different pH. 33 refs., 5 figs., 3 tabs.

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