München 2019 – wissenschaftliches Programm

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K: Fachverband Kurzzeit- und angewandte Laserphysik

K 9: Poster

K 9.6: Poster

Donnerstag, 21. März 2019, 16:30–18:30, Durchgangshalle

µTRLFS: Spatially- and time-resolved laser fluorescence spectroscopy of Eu(III) sorption on different granites — •Konrad Molodtsov^1,2 and Moritz Schmidt¹ — ¹Helmholtz-Zentrum Dresden-Rossendorf (HZDR) — ²TU Dresden

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 different granite samples 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 to visualize the sorption capacity and speciation distribution.