Erlangen 2018 – wissenschaftliches Programm

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K: Fachverband Kurzzeit- und angewandte Laserphysik

K 2: Optical Methods - Light and Radiation Sources

K 2.5: Vortrag

Montag, 5. März 2018, 17:30–17:45, MB HS

µTRLFS: Spatially- and time-resolved laser fluorescence spectroscopy of Eu(III) sorption on Eibenstock granite — •Konrad Molodtsov^{1, 2} and Moritz Schmidt¹ — ¹Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Resource Ecology, Germany — ²Technische Universität Dresden, Germany

Time-resolved laser fluorescence spectroscopy (TRLFS) is a widely used method to obtain information about the surrounding chemical environment of fluorophores with trace concentration sensitivity. This method allows determining the symmetry and grade of complexation of the fluorophore and provides information about the surrounding quenchers, mainly water as well. For highly heterogeneous systems however distinguishing and separating multiple binding species becomes an unsolvable problem. In this study a new method called µTRLFS is introduced, which will add a spatial dimension to TRLFS, giving the possibility to separate a multi-phase system into discrete single-phase systems. Because of its advantageous fluorescence properties we use europium as an analogue for Am(III) and Cm(III) to study the sorption behaviour of granite as a possible host rock for high-level nuclear waste repositories. Spatially resolved sorption experiments with Eu(III) on granite samples from Eibenstock in Erzgebirge, Germany are presented. These samples are excited by a focused and pulsed UV laser beam, and scanned with a resolution of 20 µm. Through this approach it becomes possible to characterize Eu(III) sorption on single grains of the complex material by mapping fluorescence intensity, band ratios, as well as lifetimes.