Adsorption of Eu(III) on a Heterogeneous Surface Studied by Time-Resolved Laser Fluorescence Microscopy (TRLFM)

Abstract

Time-resolved laser fluorescence microscopy (TRLFM) is a useful tool to simultaneously investigate the intensity, location, type, and surrounding chemical environment of a fluorophore. In this study, we demonstrated the applicability of TRLFM for the adsorption of Eu(III) on a natural heterogeneous surface. Different adsorption species of Eu(III) were observed on the Makabe granite surface and its constituents (biotite, plagioclase, potassium feldspar, and quartz). Eu(III) heterogeneously adsorbed on biotite, plagioclase, and quartz and homogeneously on potassium feldspar. The histograms of the fluorescence decay rates of adsorbed Eu(III) indicated efficient quenching of Eu(III) fluorescence probably due to Eu(III)-surface interaction or the formation polynuclear hydoxo Eu(III) species on the surfaces. It was also revealed that single species of Eu(III) was observed on biotite and two species on plagioclase and potassium feldspar. The adsorption of Eu(III) on the granite surface was highly heterogeneous. The TRLFM measurements of different regions of the granite surface turned into the finding of Eu(III) with different fluorescence decay rates. Comparing with the fluorescence decay histograms of the mineral constituents, Eu(III) clearly adsorbed on the feldspar family. It was also found that Eu(III) adsorbed as an outer-sphere complex and on an altered mineral of the granite.

Sorption of Eu(III) on Eibenstock granite studied by µTRLFS: A novel spatially-resolved luminescence-spectroscopic technique

“…Without that information, it is not possible to predict sorption behavior at other environmental conditions than the ones that were chosen to conduct these studies. An approach to get chemical information of the sorption species makes use of fluorescence lifetime of Eu 3+ as a fingerprint 25 . By this approach it was shown, that sorption on all major components of granite and on granite itself is heterogeneous.…”

Luminescence spectroscopy as versatile probes for chemical diagnostics on the solid–liquid interface

“…By combining fluorescence microscopy with TRLFS, the local chemical states of fluorescence ions on mineral surfaces and in biological samples [49] can also be obtained. Spatially nonaveraged information, that is, local information is invaluable particularly for interfacial processes with heterogeneous surfaces.…”

Sorption of trivalent cerium by a mixture of microbial cells and manganese oxides: Effect of microbial cells on the oxidation of trivalent cerium

“…Most REEs exhibit a trivalent oxidation state in the ambient environment. Trivalent REEs are readly adsorbed by inorganic and organic compounds such as metal oxides, hydroxides, minerals, clay minerals, microbial cells, cellulose, and resins (Coppin et al, 2002;Rabung et al, 2005;Ozaki et al, 2006;Ishida et al, 2009;Takahashi et al, 2010;Tang and Johannesson, 2010;Estes et al, 2013;Fukushi et al, 2013). Metal oxides such as Mn oxides are well known to accumulate large amounts of trivalent REEs under conditions encountered in deep-sea ferromanganese crusts and nodules (Piper, 1974;De Carlo and McMurtry, 1992;Bau et al, 1996;Ohta et al, 1999;Bau and Koschinsky, 2009).…”