Fulvic acid complexation of Eu(III) and Cm(III) at elevated temperatures studied by time-resolved laser fluorescence spectroscopy
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...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
01 September 2014
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| In: |
Dalton transactions
Year: 2014, Volume: 43, Issue: 41, Pages: 15593-15601 |
| ISSN: | 1477-9234 |
| DOI: | 10.1039/C4DT02339K |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1039/C4DT02339K Verlag, lizenzpflichtig, Volltext: https://pubs.rsc.org/en/content/articlelanding/2014/dt/c4dt02339k 
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| Author Notes: | Daniel R. Fröhlich, Andrej Skerencak-Frech, Michael Gas and Petra J. Panak |
| Summary: | 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. |
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| Item Description: | 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 |
| Physical Description: | Online Resource |
| ISSN: | 1477-9234 |
| DOI: | 10.1039/C4DT02339K |