Use of capillary electrophoresis for speciation purposes involving F-elements; application to the systems ND3+/HnPO4(3-n)- and UO22+/IO3-

Two different systems of interest for the problematic of a direct uranium-based fuel storage or disposal have been investigated by capillary electrophoresis (CE) and, in the case of uranyl, by time resolved laser induced fluorescence. For the UO22+/IO3- system, the mobility variations can be predicted from the speciation diagrams. CE appears thus as an interesting method to confirm and even to precise the involved formation constants. The mobility results concerning the Nd/phosphate system point out a disagreement at pH 3 between calculated and experimental values. They also point out the limits of the method, at pH 5, when sorption and precipitation processes occur. (authors)