TY - JOUR A1 - Müller, Katharina A1 - Foerstendorf, Harald A1 - Steudtner, Robin A1 - Tsushima, Satoru A1 - Kumke, Michael Uwe A1 - Lefèvre, Grégory A1 - Rothe, Jörg A1 - Mason, Harris A1 - Szabó, Zoltán A1 - Yang, Ping A1 - Adam, Christian K. R. A1 - André, Rémi A1 - Brennenstuhl, Katlen A1 - Chiorescu, Ion A1 - Cho, Herman M. A1 - Creff, Gaëlle A1 - Coppin, Frédéric A1 - Dardenne, Kathy A1 - Den Auwer, Christophe A1 - Drobot, Björn A1 - Eidner, Sascha A1 - Hess, Nancy J. A1 - Kaden, Peter A1 - Kremleva, Alena A1 - Kretzschmar, Jerome A1 - Krüger, Sven A1 - Platts, James A. A1 - Panak, Petra A1 - Polly, Robert A1 - Powell, Brian A. A1 - Rabung, Thomas A1 - Redon, Roland A1 - Reiller, Pascal E. A1 - Rösch, Notker A1 - Rossberg, André A1 - Scheinost, Andreas C. A1 - Schimmelpfennig, Bernd A1 - Schreckenbach, Georg A1 - Skerencak-Frech, Andrej A1 - Sladkov, Vladimir A1 - Solari, Pier Lorenzo A1 - Wang, Zheming A1 - Washton, Nancy M. A1 - Zhang, Xiaobin T1 - Interdisciplinary Round-Robin Test on molecular spectroscopy of the U(VI) Acetate System JF - ACS omega / American Chemical Society N2 - A comprehensive molecular analysis of a simple aqueous complexing system. U(VI) acetate. selected to be independently investigated by various spectroscopic (vibrational, luminescence, X-ray absorption, and nuclear magnetic resonance spectroscopy) and quantum chemical methods was achieved by an international round-robin test (RRT). Twenty laboratories from six different countries with a focus on actinide or geochemical research participated and contributed to this scientific endeavor. The outcomes of this RRT were considered on two levels of complexity: first, within each technical discipline, conformities as well as discrepancies of the results and their sources were evaluated. The raw data from the different experimental approaches were found to be generally consistent. In particular, for complex setups such as accelerator-based X-ray absorption spectroscopy, the agreement between the raw data was high. By contrast, luminescence spectroscopic data turned out to be strongly related to the chosen acquisition parameters. Second, the potentials and limitations of coupling various spectroscopic and theoretical approaches for the comprehensive study of actinide molecular complexes were assessed. Previous spectroscopic data from the literature were revised and the benchmark data on the U(VI) acetate system provided an unambiguous molecular interpretation based on the correlation of spectroscopic and theoretical results. The multimethodologic approach and the conclusions drawn address not only important aspects of actinide spectroscopy but particularly general aspects of modern molecular analytical chemistry. Y1 - 2019 U6 - https://doi.org/10.1021/acsomega.9b00164 SN - 2470-1343 VL - 4 IS - 5 SP - 8167 EP - 8177 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Marang, Laura A1 - Eidner, Sascha A1 - Kumke, Michael Uwe A1 - Benedetti, Marc F. A1 - Reiller, Pascal E. T1 - Characterization of competitive binding of Eu(III)/Cu(II) and Eu(III)/Ca(II) to Gorleben humic acid Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00167037 U6 - https://doi.org/10.1016/j.gca.2009.05.011 SN - 0016-7037 ER - TY - JOUR A1 - Marang, Laura A1 - Eidner, Sascha A1 - Kumke, Michael Uwe A1 - Benedetti, Marc F. A1 - Reiller, Pascal E. T1 - Spectroscopic characterization of the competitive binding of Eu(III), Ca(II) and Cu(II) to a sedimentary originated humic acid N2 - The competition between REE, alkaline earth and d-transition metals for organic matter binding sites is still an open field of research; particularly, the mechanisms governing these phenomena need to be characterized in more detail. In this study, we examine spectroscopically the mechanisms of competitive binding of Eu(III)/Cu(II) and Eu(III)/ Ca(II) pair to Gorleben humic acid (HA), as previously proposed in the framework of the NICA-Donnan model. The evolution of time-resolved laser induced luminescence spectra of humic-complexed Eu(Ill) showed two strikingly different environments for a comparable bound proportion for Cu(II) and Ca(II). Cu(II) seems to compete more effectively with Eu(III) inducing its release into the Donnan phase, and into the bulk solution as free Eu3+. This is evidenced both by the shapes of the spectra and by the decrease in the luminescence decay times. In contrast with that, Ca(II) induces a modification of the HA structure, which enhances the luminescence of humic-bound Eu(III), and causes a minor modification of the chemical environment of the complexed rare earth ion. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00092541 U6 - https://doi.org/10.1016/j.chemgeo.2009.03.003 SN - 0009-2541 ER - TY - JOUR A1 - Marang, Laura A1 - Reiller, Pascal E. A1 - Eidner, Sascha A1 - Kumke, Michael Uwe A1 - Benedetti, Marc F. T1 - Combining spectroscopic and potentiometric approaches to characterize competitive binding to humic substances N2 - In an area that contains high concentrations of natural organic matter, it is expected that it plays an important role on the behavior of rare earth elements (REE), like europium, and of trivalent actinides. Competitive interactions with H+, inorganic species, major cations, e.g. Ca(II) or Mg(II), could influence these metals transport and bioavailability. Competitive experiments between cations, which can bind differently to humic substances and Eu3+,will bring an improved understanding of the competitive mechanisms. The aim of this study is to acquire data for Eu(III)/Cu(II) and Eu(III)/Ca(II) competitive binding to a sedimentary originated humic acid (Gorleben, Germany). The NICA-Donnan parameters for Ca2+, Cu2+, and Eu3+ obtained from competitive binding experiments using Ca2+ or Cu2+ ion selective electrodes were used to model time-resolved laser fluorescence spectroscopy (TRLFS) measurements. Eu3+ and Cu2+ are in direct competition for the same type of sites,whereas Ca2+ has an indirect influence through electrostatic binding. Y1 - 2008 UR - http://pubs.acs.org/doi/full/10.1021/es702858p U6 - https://doi.org/10.1021/Es702858p ER -