Luminescence Analysis of Actinides: Instrumentation, Applications, Quantification, Future Trends, and Quality Assurance

Billard, Isabelle; Geipel, Gerhard

doi:10.1007/4243_2008_050

Cited by 15 publications

(7 citation statements)

References 96 publications

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“…Although the luminescence lifetimes of all samples were generally strongly quenched, a shorter lifetime of the U(VI) phosphate species was observed than for the U(VI) hydroxo species (not shown). This agrees with literature data, in which luminescence lifetimes of 6.0 μs and 4.7 ± 0.1 μs were reported for UO 2 HPO 4 and (UO 2 ) x (PO 4 ) y , respectively, 16 in contrast to 19.8 ± 1.8 μs for (UO 2 ) 3 (OH) 5 + . 17 The TRLFS results are further supported by the thermodynamic speciation calculations: UO 2 HPO 4 and (UO 2 ) 3 (OH) 5…”

Section: Environmental Science and Technologysupporting

confidence: 93%

Calorimetrically Determined U(VI) Toxicity inBrassica napusCorrelates with Oxidoreductase Activity and U(VI) Speciation

Sachs

Geipel

Bok

et al. 2017

Environ. Sci. Technol.

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Radioecological studies depend on the quantitative toxicity assessment of environmental radionuclides. At low dose exposure, the life span of affected organisms is barely shortened, enabling the transfer of radionuclides through an almost-intact food chain. Lethality-based toxicity estimates are not adequate in this regime because they require higher concentrations. However, increased radionuclide concentration alters its speciation, rendering the extrapolation to the low dose exposure chemically inconsistent. Here, we demonstrate that microcalorimetry provides a sensitive real-time monitor of toxicity of uranium (in the U(VI) oxidation state) in a plant cell model of Brassica napus. We introduce the calorimetric descriptor "metabolic capacity" and show that it correlates with enzymatically determined cell viability. It is independent of physiological models and robust against the naturally occurring fluctuations in the metabolic response to U(VI) of plant cell cultures. In combination with time-resolved laser-induced fluorescence spectroscopy and thermodynamic modeling, we show that the plant cell metabolism is affected predominantly by hydroxo-species of U(VI) with an IC threshold of ∼90 μM. The data emphasize the yet-little-exploited potential of microcalorimetry for the speciation-sensitive ecotoxicology of radionuclides.

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Section: Environmental Science and Technologysupporting

confidence: 93%

Calorimetrically Determined U(VI) Toxicity inBrassica napusCorrelates with Oxidoreductase Activity and U(VI) Speciation

Sachs

Geipel

Bok

et al. 2017

Environ. Sci. Technol.

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“…11B). These four peaks are attributed to the presence of uranyl ions (Billard and Geipel 2008) in silica minerals. The general shape of the spectra (Fig.…”

Section: Uranium: Localization and Studymentioning

confidence: 99%

Root Calcretes and Uranium-Bearing Silcretes At Sedimentary Discontinuities In the Miocene of the Madrid Basin (Toledo, Spain)

Bustillo

Plet

Alonso-Zarza

2014

Journal of Sedimentary Research

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This paper reports a detailed study of the calcrete and silcrete profiles in the Miocene detrital deposits in the western area of Madrid, at the boundary of two main sedimentary units. The aims of this work were to better understand the pedogenic and diagenetic environments in which these profiles formed and to determine the cause(s) of their enrichment in uranium. Calcrete and silcrete duricrusts are characteristic features of closed continental basins in semiarid climates; this paper discusses the significance of duricrusts as indicators of important change in such basins.The detailed macromorphological, micromorphological, and geochemical study of three duricrust profiles revealed the sequence of pedogenic, vadose, and groundwater processes responsible for their formation. During the first stage of their development, carbonate laminae formed a white ''grill-like'' structure within the detrital parent materials. The microstructure and macrostructure of the carbonate, which includes alveolar septal structures and needle-fiber calcite, indicates the important role of roots and their associated microorganisms in calcrete formation. Early silicification occurred in the pedogenic-vadose environment affecting the detrital parent material, roots, and calcretes, forming an early silcrete defined by opaline glaebules and silica rhizoliths. The detailed preservation of the cells in the silicified roots denotes the early replacement of root organic matter. The green or green-yellowish fluorescence of the silicified root structures under short-wavelength UV shows their preferential enrichment in uranium. Calcitization and silicification coexisted in the pedogenic vadose environment, leading to several reversible replacements of calcite and silica. Later, the rise of the water table promoted silicification under phreatic conditions, as indicated by the good preservation of the texture of the detrital host rocks and calcretes. Other silcrete textures, such as ovoidal opaline accumulations, intraclasts produced by autobrecchification, and vadose silica cements, indicate later vadose environments, and consequently variations in the water table.The geochemical features of the calcretes and silcretes (major, minor, and rare earth elements) were inherited from their parent materials. The rare-earth-element patterns of some silcretes show them to have a positive Ce anomaly, suggesting that oxidizing conditions reigned during their formation. The good correlation between silica and uranium suggests that the silica phases acquired uranium through the direct silicification of roots that had fixed uranium from organic matter.This study shows that calcrete-silcrete duricrusts provide detailed information regarding the processes occurring in semiarid continental basins. In the studied basin, roots played a key role in both the development of the duricrust profiles and their enrichment in uranium. These duricrusts provide important information for understanding the overall stratigraphy of the studied basin and its large-scale ...

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“…The fluorescence spectra are characterized by many vibrational progressions based on a common electronic origin, where vibrational progression in the O–U–O symmetric stretching mode is dominated . Such a feature has been utilized to study speciation of uranyl in natural and artificial environments by virtue of the time-resolved laser-induced fluorescence (TRLIF) experiment technique. − TRLIF as a powerful tool is important for molecular-level understanding of the interaction of actinides with various inorganic and organic/biochemical ligands and provides the basic information for handling actinide contaminations in the environment and in biological systems. − Besides, the intensity distribution of fluorescence spectra changes as the ligand coordinated to uranyl ion varies. Therefore, the exploration of the coordination structure, electronic structure, and excited states of uranyl compounds is essential to understanding of the nature of the fluorescence spectra.…”

Section: Introductionmentioning

confidence: 99%

Excited States and Luminescent Properties of UO₂F₂ and Its Solvated Complexes in Aqueous Solution

Wang

Pan

et al. 2014

Inorg. Chem.

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The electronic absorption and emission spectra of free UO2F2 and its water solvated complexes below 32,000 cm(-1) are investigated at the levels of ab initio CASPT2 and CCSD(T) with inclusion of scalar relativistic and spin-orbit coupling effects. The influence of the water coordination on the electronic spectra of UO2F2 is explored by investigating the excited states of solvated complexes (H2O)nUO2F2 (n = 1-3). In these uranyl complexes, water coordination is found to have appreciable influence on the (3)Δ (Ω = 1g) character of the luminescent state and on the electronic spectral shape. The simulated luminescence spectral curves based on the calculated spectral parameters of (H2O)nUO2F2 from CCSD(T) approach agree well with experimental spectra in aqueous solution at both near-liquid-helium temperature and room temperature. The possible luminescence spectra of free UO2F2 in gas phase are predicted on the basis of CASPT2 and CCSD(T) results, respectively, by considering three symmetric vibration modes. The effect of competition between spin-orbit coupling and ligand field repulsion on the luminescent state properties is discussed.

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Luminescence Analysis of Actinides: Instrumentation, Applications, Quantification, Future Trends, and Quality Assurance

Cited by 15 publications

References 96 publications

Calorimetrically Determined U(VI) Toxicity inBrassica napusCorrelates with Oxidoreductase Activity and U(VI) Speciation

Calorimetrically Determined U(VI) Toxicity inBrassica napusCorrelates with Oxidoreductase Activity and U(VI) Speciation

Root Calcretes and Uranium-Bearing Silcretes At Sedimentary Discontinuities In the Miocene of the Madrid Basin (Toledo, Spain)

Excited States and Luminescent Properties of UO₂F₂ and Its Solvated Complexes in Aqueous Solution

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Luminescence Analysis of Actinides: Instrumentation, Applications, Quantification, Future Trends, and Quality Assurance

Cited by 15 publications

References 96 publications

Calorimetrically Determined U(VI) Toxicity inBrassica napusCorrelates with Oxidoreductase Activity and U(VI) Speciation

Calorimetrically Determined U(VI) Toxicity inBrassica napusCorrelates with Oxidoreductase Activity and U(VI) Speciation

Root Calcretes and Uranium-Bearing Silcretes At Sedimentary Discontinuities In the Miocene of the Madrid Basin (Toledo, Spain)

Excited States and Luminescent Properties of UO2F2 and Its Solvated Complexes in Aqueous Solution

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Excited States and Luminescent Properties of UO₂F₂ and Its Solvated Complexes in Aqueous Solution