Isotopic abundance determination by inductively coupled plasma high-resolution laser excited atomic and ionic fluorescence spectroscopy

Inductively coupled plasma-laser excited atomic fluorescence spectroscopy (ICP-LEAFS) has been successfully applied to isotopic analysis for the first time. The criteria for selecting useful excitation/fluorescence line pairs are presented and applied to the determination of uranium isotope concentration. Calculations of the ICP-LEAFS line profiles for U II 286.57 and 288.96 nm excitation are presented and suggest that the first transition should be useful for isotopic analysis using the ICP source, with a multi-mode dye laser, whereas the second should not. These results were confirmed by experiment. The detection limit for U via ICP-LEAFS using the 286.57/288.96 nm excitation/fluorescence line pair was estimated to be ∼2 μg/ml. The non-resonance fluorescence determination of U dissolved in a very complex matrix was shown to be independent of spectral line interferences from the matrix elements. (author)