Uranium (VI)-transferrin system studied by time-resolved laser-induced fluorescence
S. Scapolan, E. Ansorborlo, C. Moulin and C. Madic
Radiat. Prot. Dosim. 1998, 79(1-4), pp 505-508
WORKSHOP ON INTAKES OF RADIONUCLIDES: Occupational and Public Exposure - Proceedings of a Workshop held in Avignon, France. September 15-18 1997
The complexation of uranium with transferrin plays a major role in the biokinetic behaviour of uranium after internal contamination. However, few data are available on the formation constants and stoichiometry of this complex. Time-resolved laser-induced fluorescence (TRLIF), which is a very selective and sensitive method for actinide and lanthanide analysis, was selected for the study of transferrin behaviour. It has been shown using fluorescence titration, that the stoichiometry of the complex that forms between uranium(VI) (U) and transferrin (Tf) is U/Tf=2/1. Under physiological conditions and at a low level uranium(VI) concentration ([U]=10-6M), the conditional complexation constant K of the complex was estimated to have a log K value of 16 using a non-linear regression mathematical model.