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Roesch P, Vogel C, Wittwer P, Huthwelker T, Borca CN, Sommerfeld T, Kluge S, Piechotta C, Kalbe U, Simon FG. Taking a look at the surface: μ-XRF mapping and fluorine K-edge μ-XANES spectroscopy of organofluorinated compounds in environmental samples and consumer products. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023. [PMID: 37335293 DOI: 10.1039/d3em00107e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
For the first time, μ-X-ray fluorescence (μ-XRF) mapping combined with fluorine K-edge μ-X-ray absorption near-edge structure (μ-XANES) spectroscopy was applied to depict per- and polyfluoroalkyl substance (PFAS) contamination and inorganic fluoride in sample concentrations down to 100 μg kg-1 fluoride. To demonstrate the matrix tolerance of the method, several PFAS contaminated soil and sludge samples as well as selected consumer product samples (textiles, food contact paper and permanent baking sheets) were investigated. μ-XRF mapping allows for a unique element-specific visualization at the sample surface and enables localization of fluorine containing compounds to a depth of 1 μm. Manually selected fluorine rich spots were subsequently analyzed via fluorine K-edge μ-XANES spectroscopy. To support spectral interpretation with respect to inorganic and organic chemical distribution and compound class determination, linear combination (LC) fitting was applied to all recorded μ-XANES spectra. Complementarily, solvent extracts of all samples were target-analyzed via LC-MS/MS spectrometry. The detected PFAS sum values range from 20 to 1136 μg kg-1 dry weight (dw). All environmentally exposed samples revealed a higher concentration of PFAS with a chain length > C8 (e.g. 580 μg kg-1 dw PFOS for Soil1), whereas the consumer product samples showed a more uniform distribution with regard to chain lengths from C4 to C8. Independent of quantified PFAS amounts via target analysis, μ-XRF mapping combined with μ-XANES spectroscopy was successfully applied to detect both point-specific concentration maxima and evenly distributed surface coatings of fluorinated organic contaminants in the corresponding samples.
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Affiliation(s)
- Philipp Roesch
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Christian Vogel
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Philipp Wittwer
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Thomas Huthwelker
- Paul Scherrer Institute, Swiss Light Sources, 5232 Villigen PSI, Switzerland
| | - Camelia N Borca
- Paul Scherrer Institute, Swiss Light Sources, 5232 Villigen PSI, Switzerland
| | - Thomas Sommerfeld
- Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Straße 11, 12489 Berlin, Germany
| | - Stephanie Kluge
- Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Straße 11, 12489 Berlin, Germany
| | - Christian Piechotta
- Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Straße 11, 12489 Berlin, Germany
| | - Ute Kalbe
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
| | - Franz-Georg Simon
- Bundesanstalt für Materialforschung und -prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
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Kanno CM, Sanders RL, Flynn SM, Lessard G, Myneni SCB. Novel apatite-based sorbent for defluoridation: synthesis and sorption characteristics of nano-micro-crystalline hydroxyapatite-coated-limestone. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:5798-5807. [PMID: 24766407 DOI: 10.1021/es405135r] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Elevated levels of fluoride (F(-)) in groundwaters of granitic and basaltic terrains pose a major environmental problem and are affecting millions of people all over the world. Hydroxyapatite (HA) has been shown to be a strong sorbent for F(-); however, low permeability of synthetic HA results in poor sorption efficiency. Here we provide a novel method of synthesizing nano- to micrometer sized HA on the surfaces of granular limestone to improve the sorption efficiency of the HA-based filter. Our experiments with granular limestone (38-63, 125-500 μm) and dissolved PO4(3-) (0.5-5.3 mM) as a function of pH (6-8) and temperature (25-80 °C) indicated rapid formation of nano- to micrometer sized HA crystals on granular limestone with the maximum surface coverage at lower pH and in the presence of multiple additions of aqueous PO4(3-). The HA crystal morphology varied with the above variables. The sorption kinetics and magnitude of F(-) sorption by HA-coated-fine limestone are comparable to those of pure HA, and the F(-) levels dropped to below the World Health Organization's drinking water limit of 79 μM for F(-) concentrations commonly encountered in contaminated potable waters, suggesting that these materials could be used as effective filters. Fluorine XANES spectra of synthetic HA reacted with F(-) suggest that the mode of sorption is through the formation of fluoridated-HA or fluorapatite at low F(-) levels and fluorite at high F(-) loadings.
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Affiliation(s)
- Cynthia M Kanno
- Department of Geosciences, Princeton University , Princeton, New Jersey 08544, United States
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Schroeder SLM, Weiher N. F K-edge X-ray absorption near-edge structure (XANES) of AlF3 polymorphs: combining ab initio calculations with Walsh correlation diagrams. Phys Chem Chem Phys 2006; 8:1807-11. [PMID: 16633665 DOI: 10.1039/b518124k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The X-ray absorption near-edge structures (XANES) at the F K-edge of alpha-AlF(3), beta-AlF(3) and a tetragonal AlF(3) phase are analysed by a combination of ab initio calculations with the FEFF8 code and a phenomenological discussion of local molecular orbital (MO) symmetries at the absorbing fluorine atoms. By means of a Walsh correlation diagram it is shown that the two intense absorption bands observed at the F K-edges of the AlF(3) polymorphs can be interpreted as transitions to anti-bonding MOs in [Al-F-Al]-units that have C(2v) and D(infinity h) point group symmetries. The energies of both anti-bonding orbitals are very insensitive to the angle between the Al-F bonds, which explains the close similarity of the XANES signatures from the three polymorphs. The FEFF8 analysis shows that the increased broadening of the XANES structure for beta-AlF(3) and the tetragonal AlF(3) phase is due to the superposition of the individual absorption spectra from the crystallographically distinct F species. The interpretation in terms of local MOs provides for the first time a "chemically intuitive" approach to investigations of solid fluorides by XANES spectroscopy and provides a simple conceptual framework for the discussion of the electronic structure in AlF(3) materials.
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Affiliation(s)
- Sven L M Schroeder
- Molecular Materials Centre, The University of Manchester, Sackville Street, PO Box 88, Manchester M60 1QD, UK.
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3s2p inelastic x-ray scattering of CaF2. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:7099-7110. [PMID: 9982156 DOI: 10.1103/physrevb.53.7099] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Hudson EA, Rehr JJ, Bucher JJ. Multiple-scattering calculations of the uranium L3-edge x-ray-absorption near-edge structure. PHYSICAL REVIEW. B, CONDENSED MATTER 1995; 52:13815-13826. [PMID: 9980598 DOI: 10.1103/physrevb.52.13815] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Rubensson JE, Eisebitt S, Nicodemus M, Böske T, Eberhardt W. Electron correlation in CaF2 studied in threshold-excited soft-x-ray fluorescence. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:9035-9045. [PMID: 9974945 DOI: 10.1103/physrevb.50.9035] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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