URANIUM SPECIATION IN BIOLOGICAL MEDIUM BY MEANS OF CAPILLARY ELECTROPHORESIS AND TIME-RESOLVED LASER-INDUCED FLUORESCENCE

The study of the chemical behavior of uranium in biological medium is still of great interest. By the use of capillary electrophoresis (CE) and time-resolved laser-induced fluorescence (TRLIF), it is possible t o characterize the different complexes of uranium. Hence, CE, using th e isoelectric focusing mode (CIEF), allows for the separation of the d ifferent complexes as a function of their isoelectric points (pI) and TRLIF as a speciation method leads to the identification at very low l evel of different uranyl complexes by temporal resolution and spectral deconvolution. Results obtained on various inorganic chemical systems (phosphate, bicarbonate) together with biological systems (citrate, t ransferrin) will be presented and discussed. The complexation between uranium and human transferrin has been pointed out through CIEF.