Fulvic acid complexation of Eu(III) and Cm(III) at elevated temperatures studied by time-resolved laser fluorescence spectroscopy

• Verfasst von: Fröhlich, Daniel R. [VerfasserIn]
• Verfasst von: Skerencak-Frech, Andrej [VerfasserIn]
• Verfasst von: Gast, Michael [VerfasserIn]
• Verfasst von: Panak, Petra [VerfasserIn]
• Titel: Fulvic acid complexation of Eu(III) and Cm(III) at elevated temperatures studied by time-resolved laser fluorescence spectroscopy
• Verf.angabe: Daniel R. Fröhlich, Andrej Skerencak-Frech, Michael Gas and Petra J. Panak
• E-Jahr: 2014
• Jahr: 01 September 2014
• Umfang: 9 S.
• Fussnoten: Gesehen am 06.11.2020 ; Electronic supplementary information (ESI) available: Single componentspectra at 20 °C in 0.1 M NaCl solution of Eu3+and Cm3+as well as all Eu- andCm-FA complexes; loading capacities of all FAs for Eu(III) in 0.1 M NaCl solutionas a function of temperature; Arrhenius plots of logβ0(T) for the interaction ofEu(III) with SR and NL FA in 0.1 M NaCl solution and Cm(III) with Gohy-573,SR and NL FA in 0.1 M NaCl solution; speciation of Cm(III) as a function of theinitial FA concentration (FA = Gohy-573) in 0.1 M NaCl solution atT= 20 and80 °C;fifactors of the different Eu(III)-FA complexes atT=20–80 °C; detailedresults of the slope analysis of all experimental series. See DOI: 10.1039/c4dt02339k
• Titel Quelle: Enthalten in: Dalton transactions
• Ort Quelle: London : Soc., 1972
• Jahr Quelle: 2014
• Band/Heft Quelle: 43(2014), 41, Seite 15593-15601
• ISSN Quelle: 1477-9234
• DOI: doi:10.1039/C4DT02339K
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1738034593

Abstract

The interaction of Eu(III) and Cm(III) with three different aquatic fulvic acids (FA) was studied as a function of the temperature (T = 20-80 °C) in 0.1 M NaCl solution by time-resolved laser fluorescence spectroscopy. The speciation of both trivalent metal ions was determined by peak deconvolution of the recorded fluorescence spectra. For each studied metal ion-FA system only one complexed species is formed under the given experimental conditions. The stability constants at 20, 40, 60 and 80 °C (log β′(T)) were determined according to the charge neutralization model. The log β′ (20 °C) for the different FAs show similar values (log β(20 °C) = 5.60-6.29). The stability constants increase continuously with increasing temperature by approximately 0.3-1.0 orders of magnitude. The reaction enthalpies and entropies are derived from the integrated Van't Hoff equation. The results show that all investigated complexation reactions are endothermic and entropy-driven.