Complex formation of uranium(VI) with the amino acids l-glycine and l-cysteine: A fluorescence emission and UV–Vis absorption study

The complexation of uranium(VI) with the amino acids l-glycine and l-cysteine has been investigated by time-resolved laser-induced fluorescence spectroscopy (TRLFS) and UV–Vis spectroscopy at a low pH range. The identified 1:1 and 1:2 uranyl-l-glycine complexes fluoresce and have similar absorbance properties. In contrast to the glycine system, uranyl forms two different non-fluorescent 1:1 complexes with l-cysteine, showing individual absorbance properties under the given experimental conditions. The corresponding complex formation constants were calculated using the spectroscopic data.

Graphical abstractThe complex formation of uranium(VI) with l-glycine and l-cysteine was studied at low pH values by use of time-resolved laser-induced fluorescence spectroscopy and UV–Vis spectroscopy. Differences in the fluorescence emission and UV absorption properties between free UO22+ and the several formed uranyl amino acid species were detected.Figure optionsDownload full-size imageDownload as PowerPoint slide