Fluorimetric estimation of U(VI) in the presence of a large excess of Th(IV)

Abstract

A fluorescence based method has been developed for the determination of trace amounts of uranium in thorium matrix using a mixture of phosphoric acid (H 3 PO 4 ) and sulfuric acid (H 2 SO 4 ), as fluorescence enhancing reagent for uranyl (UO 2 2? ) ion fluorescence. Synthetic samples mimicking the composition of ThO 2 fuel were prepared and the concentration of U(VI) was estimated. Satisfactory results are obtained when uranium is present at a concentration of 10 ppm in solid thorium samples with good precision.

Enhanced luminescence of tris(carboxylato)uranyl(vi) complexes and energy transfer to Eu(iii): a combined spectroscopic and theoretical investigation

“…have been used to bind and shield the uranyl from such environments to reduce the quenching processes. [22][23][24][25] The use of organic ligands that are commonly employed to sensitize the luminescence of lanthanide ions is seldomly found to be effective for the sensitization of uranyl ions. The primary cause of this is the non-luminescent nature of most of the organic uranyl complexes, which arises due to the thermally activated back energy transfer from the uranyl luminescent state to the low lying energy levels of the ligands.…”