The extraction of trivalent lanthanides from an aqueous phase containing 1 M NaClO4 into the room temperature ionic liquid 1-butyl-3-methylimidazolium nonafluoro-1-butanesulfonate by the beta-diketone extractant 2-thenoyltrifluoroacetone (Htta) was studied. Radiotracer distribution, absorption spectroscopy, time-resolved laser-induced fluorescence spectroscopy, and X-ray absorption fine structure measurements point to the extraction of multiple lanthanide species. At low extractant concentrations, fully hydrated aqua cations of the lanthanides are present in the ionic liquid phase. As the extractant concentration is increased 1:2 and 1:3 lanthanide:tta species are observed. In contrast, 1:4 Ln:tta complexes were observed in the extraction of lanthanides by Htta into 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide.

This study describes a new determination of the decay scheme and half-life of (93)Zr. A pure (93)Zr solution was obtained after chemical separation from the dissolution of an irradiated zircaloy sample. The concentration of (93)Zr in the solution was measured by mass spectrometry, with an isotopic dilution technique. The activity of the solution was measured by liquid scintillation counting, using an efficiency tracing method. The measurement of the activity concentration of (93)Nb(m) by X-ray spectrometry, allowed the determination of the (93)Zr decay scheme and the calculation of the (93)Zr detection efficiency. This leads to the calculation of the decay probability of (93)Zr toward (93)Nb(m) of (0.73+/-0.06) and to a half-life of (93)Zr of (1.64+/-0.06)x10(6) years. These values are discussed in comparison with the evaluated values available in the literature.

Time-resolved laser-induced fluorescence (TRLIF) has been used to investigate Eu complexes formed with inorganic and organic ligands encountered in natural waters as well as Eu complexes formed during the interaction of simulated nuclear waste glass with claywater. By comparing spectral and temporal data obtained by TRLIF on various europium solutions containing humic acids (HA) and carbonates (CO3), it has been possible to confirm the presence of mixed europium complexes such as Eu–CO3–HA. These results are quite important for speciation purposes, in particular in the framework of environmental studies.

Time-resolved laser-induced fluorescence is a unique method for direct uranium speciation at low level in the framework of environmental studies. By varying pH and uranium concentration in the absence of carbonate ions and at fixed ionic strength, it was possible, together with free uranyl UO22+, to identify spectrally and temporally all the uranium-hydroxo complexes, namely, UO2OH+, UO2(OH)2, UO2(OH)3−, (UO2)2(OH)22+, (UO2)3(OH)5+, and (UO2)3(OH)7−.