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Jung J, Park J, Choe JK, Choi Y. Perfluoroalkyl functionalized-Au nanoparticle sensor: Employing rate of spectrum shifting for highly selective and sensitive detection of per- and polyfluoroalkyl substances (PFASs) in aqueous environments. WATER RESEARCH X 2024; 24:100239. [PMID: 39193396 PMCID: PMC11347827 DOI: 10.1016/j.wroa.2024.100239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 07/15/2024] [Accepted: 07/17/2024] [Indexed: 08/29/2024]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are emerging contaminants detected ubiquitously and have negative impacts on human health and ecosystem; thus, developing in-situ sensing technique is important to ensure safety. Herein, we report a novel colorimetric-based sensor with perfluoroalkyl receptor attached to citrate coated gold nanoparticles (Citrate-Au NPs) that can detect several PFASs including perfluorocarboxylates with different chain lengths (PFHxA, PFOA, PFNA, PFDA), perfluorooctanoic sulfonate (PFOS), and perfluorooctanoic phosphonate (PFOPA). The sensor detects PFASs utilizing fluorous interaction between PFASs and the perfluoroalkyl receptor of Citrate-Au NPs in a solution at a fixed salt concentration, inducing changes in nanoparticle dispersity and the solution color. The rate of spectrum shift was linearly dependent on PFASs concentrations. Citrate-Au NPs with size between 29 - 109 nm were synthesized by adjusting citrate/Au molar ratios, and 78 nm showed the best sensitivity to PFOA concentration (with level of detection of 4.96 µM). Citrate-Au NPs only interacted with PFASs with perfluoroalkyl length > 4 and not with non-fluorinated alkyl compound (nonanoic acid). The performance of Citrate-Au NP based sensor was strongly dependent on the chain length of the perfluoroalkyl group and the head functional group; higher sensitivity was observed with longer chain over shorter chain, and with sulfonate functional group over carboxylate and phosphonate. The sensor was tested using real water samples (i.e., tap water, filtered river water), and it was found that the sensor is capable of detecting PFASs in these conditions if calibrated with the corresponding water matrix. While further optimization is needed, this study demonstrated new capability of Citrate-Au NPs based sensor for detection of PFASs in water.
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Affiliation(s)
- Jihyeun Jung
- Department of Civil & Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Junyoung Park
- Department of Civil & Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
- Institute of Construction and Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jong Kwon Choe
- Department of Civil & Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
- Institute of Construction and Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Yongju Choi
- Department of Civil & Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
- Institute of Construction and Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
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2
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Jiang Z, Denisov S, Adjei D, Mostafavi M, Ma J. Overlooked Activation Role of Sulfite in Accelerating Hydrated Electron Treatment of Perfluorosulfonates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:9427-9435. [PMID: 38747404 DOI: 10.1021/acs.est.4c01444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Photoexcitation of sulfite (SO32-) is often used to generate hydrated electrons (eaq-) in processes to degrade perfluoroalkyl and polyfluoroalkyl substances (PFASs). Conventional consensus discourages the utilization of SO32- concentrations exceeding 10 mM for effective defluorination. This has hindered our understanding of SO32- chemistry beyond its electron photogeneration properties. In contrast, the radiation-chemical study presented here, directly producing eaq- through water radiolysis, suggests that SO32- plays a previously overlooked activation role in the defluorination. Quantitative 60Co gamma irradiation experiments indicate that the increased SO32- concentration from 0.1 to 1 M enhances the defluorination rate by a remarkable 15-fold, especially for short-chain perfluoroalkyl sulfonate (PFSA). Furthermore, during the treatment of long-chain PFSA (C8F17-SO3-) with a higher concentration of SO32-, the intermediates of C8H17-SO3- and C3F7-COO- were observed, which are absent without SO32-. These observations highlight that a higher concentration of SO32- facilitates both reaction pathways: chain shortening and H/F exchange. Pulse radiolysis measurements show that elevated SO32- concentrations accelerate the bimolecular reaction between eaq- and PFSA by 2 orders of magnitude. 19F NMR measurements and theoretical simulations reveal the noncovalent interactions between SO32- and F atoms, which exceptionally reduce the C-F bond dissociation energy by nearly 40%. As a result, our study offers a more effective strategy for degrading highly persistent PFSA contaminants.
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Affiliation(s)
- Zhiwen Jiang
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China
- Institute de Chimie Physique, UMR8000 CNRS/Université Paris-Saclay, Orsay 91405, France
| | - Sergey Denisov
- Institute de Chimie Physique, UMR8000 CNRS/Université Paris-Saclay, Orsay 91405, France
| | - Daniel Adjei
- Institute de Chimie Physique, UMR8000 CNRS/Université Paris-Saclay, Orsay 91405, France
| | - Mehran Mostafavi
- Institute de Chimie Physique, UMR8000 CNRS/Université Paris-Saclay, Orsay 91405, France
| | - Jun Ma
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China
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Thijs M, Laletas E, Quinn CM, Raguraman SV, Carr B, Bierganns P. Total and Class-Specific Determination of Fluorinated Compounds in Consumer and Food Packaging Samples Using Fluorine-19 Solid-State Nuclear Magnetic Resonance Spectroscopy. Anal Chem 2024; 96:8282-8290. [PMID: 38717341 DOI: 10.1021/acs.analchem.3c04404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Hamburger wrapping paper, coated with water-based barrier coatings, used in the food packaging industry was studied by using the total organic fluorine (TOF) method based on combustion ion chromatography and fluorine-19 solid-state nuclear magnetic resonance (19F ss-NMR) spectroscopy. Although the TOF method is a fast and affordable method used to screen for per- and polyfluoroalkyl substances (PFAS), the amount of fluorine it measures is heavily dependent on the extraction step and, therefore could lead to inaccurate results. Fluorine-19 ss-NMR spectroscopy can differentiate between organic and inorganic fluorinated sources, eliminating the need for sample clean up. To illustrate this, the 19F ss-NMR spectra of clean coated paper samples that contained naturally occurring F- ions from the talc raw material and spiked samples containing perfluorooctanoic acid were compared. A range of experimental conditions was explored to improve sensitivity for low PFAS concentrations (in the order of 10-20 mg/kg). Despite the disadvantages of ss-NMR spectroscopy, such as the low limit of detection and resolution, the results demonstrate it can be a viable tool to directly detect PFAS moieties in consumer and food packaging. Therefore, 19F solid-state NMR spectroscopy challenges and complements current methods, which only provide indirect evidence of the presence of PFAS.
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Affiliation(s)
- Mike Thijs
- Solenis Belgium BVBA, Global Technology, Nijverheidsstraat 98, 2160 Wommelgem, Belgium
| | - Ernest Laletas
- Solenis LLC, Global Technology, 500 Hercules Road, Wilmington, Delaware 19808, United States
| | - Caitlin M Quinn
- Department of Chemistry and Biochemistry, University of Delaware, 032 Brown Lab, Newark, Delaware 19716, United States
| | - Subbu V Raguraman
- Solenis Technologies Germany GmbH, Global Technology, Krefelderstrasse 560, 41066 Mönchengladbach, Germany
| | - Bryan Carr
- Solenis LLC, Global Technology, 500 Hercules Road, Wilmington, Delaware 19808, United States
| | - Patric Bierganns
- Solenis Technologies Germany GmbH, Global Technology, Krefelderstrasse 560, 41066 Mönchengladbach, Germany
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4
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Goranov AI, Sørmo E, Hagemann N, Cornelissen G, Zimmerman AR, Hatcher PG. Using the benzenepolycarboxylic acid (BPCA) method to assess activated biochars and their PFAS sorption abilities. CHEMOSPHERE 2024; 355:141750. [PMID: 38522671 DOI: 10.1016/j.chemosphere.2024.141750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 02/05/2024] [Accepted: 03/16/2024] [Indexed: 03/26/2024]
Abstract
Activated carbon (AC) has important industrial and environmental applications as it has excellent abilities to sorb contaminants such as per- and polyfluoroalkyl substances (PFAS). Current research aims to develop activated biochars (AB) from renewable biomass to replace AC that is produced from fossil feedstock. Both AC and AB are primarily comprised of condensed aromatic carbon (ConAC), the component that is the focus of this study. ConAC is characterized to determine its relationship with biochar activation conditions and PFAS sorption, which are understudied at present. Benzenepolycarboxylic acid (BPCA) markers for ConAC were quantified in steam-activated biochars (AB-Steam) and carbon dioxide-activated biochars (AB-CO2) prepared from waste timber at different temperatures (800, 850, 900 °C) and molar ratios of feedstock-carbon:steam (0.50 - 1.25). A non-activated biochar was also included as a reference. ConAC relative to total organic carbon content was higher in AB-Steam than in AB-CO2 (92 ± 2 % vs. 81 ± 11%). The ratio of benzenehexa- (B6CA) to benzenepentacarboxylic (B5CA) acids revealed that AB-Steam also had larger ConAC clusters than AB-CO2. These findings provide novel evidence that steam activation is more effective than CO2 activation in creating ConAC. To assess how ConAC impacts AB sorption abilities, AB-Steam were used to remediate PFAS from contaminated soils. The observed strong correlations between ConAC content and sorption of long-chain PFAS suggest the importance of hydrophobic interactions between PFAS tails and ConAC. Poor correlations for short-chain PFAS, on the other hand, indicated the existence of electrostatic repulsion interactions between PFAS head groups and ConAC. Collectively, these results explain the great ability of AB-Steam to sorb PFAS from contaminated soils (up to 100% remediation). More broadly, this work demonstrates that the BPCA method can be a valuable tool to assess the quality of biochars and other carbonaceous sorbents in relation to their production conditions or contaminant sorption abilities.
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Affiliation(s)
- Aleksandar I Goranov
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, USA.
| | - Erlend Sørmo
- Department of Environmental Chemistry, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Environmental Science and Natural Resource Management (MINA), University of Life Sciences (NMBU), Ås, Norway
| | - Nikolas Hagemann
- Agroscope, Reckenholz, Switzerland; Ithaka Institute for Carbon Strategies, Arbaz, Switzerland and Goldbach, Germany
| | - Gerard Cornelissen
- Department of Environmental Chemistry, Norwegian Geotechnical Institute (NGI), Oslo, Norway; Faculty of Environmental Science and Natural Resource Management (MINA), University of Life Sciences (NMBU), Ås, Norway
| | - Andrew R Zimmerman
- Department of Geological Sciences, University of Florida, Gainesville, FL, USA
| | - Patrick G Hatcher
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA, USA.
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5
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Zhang H, Zhu L, Zhang Y, Héroux P, Cai L, Liu Y. Removal of per- and polyfluoroalkyl substances from water by plasma treatment: Insights into structural effects and underlying mechanisms. WATER RESEARCH 2024; 253:121316. [PMID: 38377926 DOI: 10.1016/j.watres.2024.121316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 02/22/2024]
Abstract
Non-thermal plasma emerges as a promising technology for per- and polyfluoroalkyl substances (PFAS) decomposition due to its notable efficacy and environmentally friendly characteristics. In this study, we demonstrated the efficacy of a falling film dielectric barrier discharge (DBD) system for the removal of 10 PFAS, including perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkyl sulfonic acids (PFSAs) and hexafluoropropylene oxide (HFPO) oligomer acids. Results showed that compounds with fluoroalkyl chain length>4 were effectively decomposed within 100 min, with long-chain PFAS demonstrating more pronounced removal performance than their short-chain analogues. The superior removal but low defluorination observed in HFPO oligomer acids could be ascribed to their ether-based structural features. The integration of experimental results with density functional theory (DFT) calculations revealed that the synergistic effects of various reactive species are pivotal to their efficient decomposition, with electrons, OH•, and NO2• playing essential roles. In contrast, the degradation of PFSAs was more dependent on electron attack than that of PFCAs and HFPO oligomer acids. Significantly, the most crucial degradation pathway for HFPO oligomer acids was the cleavage of ether CO, whether through radical or electron attack. Furthermore, the demonstrated effective removal in various water matrices showed the potential of the plasma system for removing PFAS in complex aquatic environments. This study provided mechanistic insights into PFAS degradation behavior in plasma processes, and it underscored the vital influence of molecular structures on degradability, thereby contributing to the further development and regulation of plasma-based technologies for treating PFAS in water.
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Affiliation(s)
- Han Zhang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Luxiang Zhu
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Yinyin Zhang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Paul Héroux
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada
| | - Li Cai
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Yanan Liu
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai institute of pollution control and ecological security, Shanghai 200092, China.
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6
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Hubert M, Arp HPH, Hansen MC, Castro G, Meyn T, Asimakopoulos AG, Hale SE. Influence of grain size, organic carbon and organic matter residue content on the sorption of per- and polyfluoroalkyl substances in aqueous film forming foam contaminated soils - Implications for remediation using soil washing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 875:162668. [PMID: 36894086 DOI: 10.1016/j.scitotenv.2023.162668] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/24/2023] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
A soil that was historically contaminated with Aqueous Film Forming Foam (AFFF) was dry sieved into size fractions representative of those produced during soil washing. Batch sorption tests were then conducted to investigate the effect of soil parameters on in situ per- and polyfluoroalkyl substances (PFAS) sorption of these different size fractions: < 0.063 mm, 0.063 to 0.5 mm, 0.5 to 2 mm, 2 to 4 mm, 4 to 8 mm, and soil organic matter residues (SOMR). PFOS (513 ng/g), 6:2 FTS (132 ng/g) and PFHxS (58 ng/g) were the most dominant PFAS in the AFFF contaminated soil. Non-spiked, in situ Kd values for 19 PFAS ranged from 0.2 to 138 L/Kg (log Kd -0.8 to 2.14) for the bulk soil and were dependant on the head group and perfluorinated chain length (spanning C4 to C13). The Kd values increased with decreasing grain size and increasing organic carbon content (OC), which were correlated to each other. For example, the PFOS Kd value for silt and clay (< 0.063 mm, 17.1 L/Kg, log Kd 1.23) were approximately 30 times higher compared to the gravel fraction (4 to 8 mm, 0.6 L/Kg, log Kd -0.25). The highest PFOS Kd value (116.6 L/Kg, log Kd 2.07) was found for the SOMR fraction, which had the highest OC content. Koc values for PFOS ranged from 6.9 L/Kg (log Koc 0.84) for the gravel fraction to 1906 L/Kg (log Koc 3.28) for the silt and clay, indicating that the mineral composition of the different size fractions also influenced sorption. The results here emphasize the need to separate coarse-grained fractions and fine-grained fractions, and in particular the SOMR, to optimize the soil washing process. Higher Kd values for the smaller size fractions indicate that coarser soils are better suited for soil washing.
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Affiliation(s)
- Michel Hubert
- Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway; Norwegian Geotechnical Institute (NGI), NO-0806 Oslo, Norway.
| | - Hans Peter H Arp
- Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway; Norwegian Geotechnical Institute (NGI), NO-0806 Oslo, Norway
| | | | - Gabriela Castro
- Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway
| | - Thomas Meyn
- Norwegian University of Science and Technology (NTNU), NO-7491 Trondheim, Norway
| | | | - Sarah E Hale
- Norwegian Geotechnical Institute (NGI), NO-0806 Oslo, Norway
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7
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Ghorbani Gorji S, Hawker DW, Mackie R, Higgins CP, Bowles K, Li Y, Kaserzon S. Sorption affinity and mechanisms of per-and polyfluoroalkyl substances (PFASs) with commercial sorbents: Implications for passive sampling. JOURNAL OF HAZARDOUS MATERIALS 2023; 457:131688. [PMID: 37257384 DOI: 10.1016/j.jhazmat.2023.131688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 04/17/2023] [Accepted: 05/22/2023] [Indexed: 06/02/2023]
Abstract
Effective monitoring tools, including passive samplers, are essential for the wide range of per- and polyfluoroalkyl substances (PFASs) in aquatic matrices. However, knowledge of the extent and mechanisms of PFASs sorption with sorbents in a passive sampling context is limited. To address this, sorption behavior of 45 anionic, neutral and zwitterionic PFASs ranging in perfluorocarbon chain length (C3-C16) and functional groups with 11 different commercial sorbents (cross-linked β-cyclodextrin polymers, activated carbon, anion exchange (AE), cation exchange, hydrophilic-lipophilic balanced (HLB) and non-polar) was investigated. A broad range of equilibrium sorbent-MilliQ water (MQ) distribution coefficients (Kd) were observed (10-1.95 to 108.30 mL g-1). Similar sorbent types (e.g., various AE and HLB sorbents) exhibited very different sorption behavior, likely due to their different polymeric structures and relative importance of sorbate/sorbent interactions other than coulombic interactions. HLB and AE with hydroxyl functionalities are most effective for sampling of the full suite of PFASs. Reduced sorptive affinity was observed in the presence of matrix co-constituents in wastewater influent for most PFASs. HLB had the smallest reduction in log Kd in wastewater suggesting that these sorbents are appropriate for applications in complex matrices. Sufficient sorbent capacity was observed for linear uptake of many target analytes which facilitates passive sampling.
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Affiliation(s)
- Sara Ghorbani Gorji
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia.
| | - Darryl W Hawker
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia; School of Environment and Science, Griffith University, Brisbane, Australia
| | - Rachel Mackie
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia
| | - Christopher P Higgins
- Department of Civil and Environmental Engineering, Colorado School of Mines, CO, United States
| | - Karl Bowles
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia; Jacobs, North Sydney, Australia
| | - Yan Li
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia
| | - Sarit Kaserzon
- Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, Brisbane, Australia
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8
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Camdzic D, Dickman RA, Joyce AS, Wallace JS, Ferguson PL, Aga DS. Quantitation of Total PFAS Including Trifluoroacetic Acid with Fluorine Nuclear Magnetic Resonance Spectroscopy. Anal Chem 2023; 95:5484-5488. [PMID: 36946571 PMCID: PMC10601338 DOI: 10.1021/acs.analchem.2c05354] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Fluorine nuclear magnetic resonance (19F-NMR) spectroscopy has been shown to be a powerful tool capable of quantifying the total per- and polyfluoroalkyl substances (PFAS) in a complex sample. The technique relies on the characteristic terminal -CF3 shift (-82.4 ppm) in the alkyl chain for quantification and does not introduce bias due to sample preparation or matrix effects. Traditional quantitative analytical techniques for PFAS, such as liquid chromatography-mass spectrometry (LC-MS) and combustion ion chromatography (CIC), contain inherent limitations that make total fluorine analysis challenging. Here, we report a sensitive 19F-NMR method for the analysis of total PFAS, with a limit of detection of 99.97 nM, or 50 μg/L perfluorosulfonic acid. To demonstrate the capabilities of 19F-NMR, the technique was compared to two commonly used methods for PFAS analysis: total oxidizable precursor (TOP) assay and LC-high resolution MS analysis for targeted quantification and suspect screening. In both cases, the 19F-NMR analyses detected higher total PFAS quantities than either the TOP assay (63%) or LC-MS analyses (65%), suggesting that LC-MS and TOP assays can lead to underreporting of PFAS. Importantly, the 19F-NMR detected trifluoroacetic acid at a concentration more than five times the total PFAS concentration quantified using LC-MS in the wastewater sample. Therefore, the use of 19F-NMR to quantify the total PFAS in highly complex samples can be used to complement classic TOP or LC-MS approaches for more accurate reporting of PFAS contamination in the environment.
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Affiliation(s)
- Dino Camdzic
- Department of Chemistry, University at Buffalo SUNY, Buffalo, New York 14260, United States
| | - Rebecca A Dickman
- Department of Chemistry, University at Buffalo SUNY, Buffalo, New York 14260, United States
| | - Abigail S Joyce
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Joshua S Wallace
- Department of Chemistry, University at Buffalo SUNY, Buffalo, New York 14260, United States
- RENEW Institute, University at Buffalo SUNY, Buffalo, New York 14260, United States
| | - P Lee Ferguson
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Diana S Aga
- Department of Chemistry, University at Buffalo SUNY, Buffalo, New York 14260, United States
- RENEW Institute, University at Buffalo SUNY, Buffalo, New York 14260, United States
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9
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Smeltz MG, Clifton MS, Henderson WM, McMillan L, Wetmore BA. Targeted Per- and Polyfluoroalkyl substances (PFAS) assessments for high throughput screening: Analytical and testing considerations to inform a PFAS stock quality evaluation framework. Toxicol Appl Pharmacol 2023; 459:116355. [PMID: 36535553 PMCID: PMC10367912 DOI: 10.1016/j.taap.2022.116355] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/25/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Per- and polyfluoroalkyl substances (PFAS) represent a large chemical class lacking hazard, toxicokinetic, and exposure information. To accelerate PFAS hazard evaluation, new approach methodologies (NAMs) comprised of in vitro high-throughput toxicity screening, toxicokinetic data, and computational modeling are being employed in read across strategies to evaluate the larger PFAS landscape. A critical consideration to ensure robust evaluations is a parallel assessment of the quality of the screening stock solutions, where dimethyl sulfoxide (DMSO) is often the diluent of choice. Challenged by the lack of commercially available reference standards for many of the selected PFAS and reliance on mass spectrometry approaches for such an evaluation, we developed a high-throughput framework to evaluate the quality of screening stocks for 205 PFAS selected for these NAM efforts. Using mass spectrometry coupled with either liquid or gas chromatography, a quality scoring system was developed that incorporated observations during mass spectral examination to provide a simple pass or fail notation. Informational flags were used to further describe findings regarding parent analyte presence through accurate mass identification, evidence of contaminants and/or degradation, or further describe characteristics such as isomer presence. Across the PFAS-DMSO stocks tested, 148 unique PFAS received passing quality scores to allow for further in vitro testing whereas 57 received a failing score primarily due to detection issues or confounding effects of DMSO. Principle component analysis indicated vapor pressure and Henry's Law Constant as top indicators for a failed quality score for those analyzed by gas chromatography. Three PFAS in the hexafluoropropylene oxide family failed due to degradation in DMSO. As the PFAS evaluated spanned over 20 different structural categories, additional commentary describes analytical observations across specific groups related to PFAS stock composition, detection, stability, and methodologic considerations that will be useful for informing future analytical assessment and downstream HTS efforts. The high-throughput stock quality scoring workflow presented holds value as a tool to evaluate chemical presence and quality efficiently and for informing data inclusion in PFAS or other NAM screening efforts.
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Affiliation(s)
- Marci G Smeltz
- Center for Computational Toxicology and Exposure, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, United States of America
| | - M Scott Clifton
- Center for Environmental Measurement and Modeling, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, United States of America
| | - W Matthew Henderson
- Center for Environmental Measurement and Modeling, Office of Research and Development, United States Environmental Protection Agency, Athens, GA 23605, United States of America
| | - Larry McMillan
- National Caucus and Center on Black Aged, Inc, Durham, NC, United States of America
| | - Barbara A Wetmore
- Center for Computational Toxicology and Exposure, Office of Research and Development, United States Environmental Protection Agency, Research Triangle Park, NC 27711, United States of America.
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10
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Liu D, Tang B, Nie S, Zhao N, He L, Cui J, Mao W, Jin H. Distribution of per- and poly-fluoroalkyl substances and their precursors in human blood. JOURNAL OF HAZARDOUS MATERIALS 2023; 441:129908. [PMID: 36115093 DOI: 10.1016/j.jhazmat.2022.129908] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/26/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
Many studies have examined per- and poly-fluoroalkyl substances (PFASs) in human blood. However, the distribution of PFASs in human blood remains not well known, especially for perfluorooctane sulfonate (PFOS) precursors. In this study, human blood samples (n = 162) were collected from general Chinese population, and then the isomer-specific partitioning of PFASs between human plasma and red blood cells (RBCs) were investigated. Perfluorooctanoate (PFOA) and PFOS were consistently the predominant PFASs in both human plasma and RBCs. In human blood, among C4-C7 perfluoroalkyl carboxylates (PFCAs), the calculated mean mass fraction in plasma (Fp) values increased from 0.76 to 0.82 with the increasing chain length. C7-C13 PFCAs exhibited a trend of gradually decreasing mean Fp with chain length. Among PFAS precursors, 6:2 fluorotelomer phosphate diester had the highest mean Fp value (0.87 ± 0.11). Calculated Fp values of N-methyl perfluorooctanesulfonamide (N-MeFOSA) and N-ethyl perfluorooctanesulfonamide (N-EtFOSA) were 0.66 ± 0.13 and 0.70 ± 0.12, respectively. Individual branched isomers consistently had greater Fp values than their corresponding linear isomers for PFOA, PFHxS, and perfluoroctane sulfonamide. To our knowledge, this study first reports the distribution of N-MeFOSA and N-EtFOSA in human blood, contributing to the better understanding of the occurrence and fate of PFASs in humans.
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Affiliation(s)
- Daxi Liu
- College of Environmental Science and Technology, Hebei University of Science & Technology, Shijiazhuang, Hebei 050018, PR China
| | - Bo Tang
- College of Environmental Science and Technology, Hebei University of Science & Technology, Shijiazhuang, Hebei 050018, PR China
| | - Saisai Nie
- College of Environmental Science and Technology, Hebei University of Science & Technology, Shijiazhuang, Hebei 050018, PR China
| | - Nan Zhao
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, PR China
| | - Li He
- College of Environmental Science and Technology, Hebei University of Science & Technology, Shijiazhuang, Hebei 050018, PR China
| | - Jiansheng Cui
- College of Environmental Science and Technology, Hebei University of Science & Technology, Shijiazhuang, Hebei 050018, PR China.
| | - Weili Mao
- Department of Pharmacy, Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang 324000, PR China
| | - Hangbiao Jin
- Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, PR China.
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11
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Parker BA, Knappe DRU, Titaley IA, Wanzek TA, Field JA. Tools for Understanding and Predicting the Affinity of Per- and Polyfluoroalkyl Substances for Anion-Exchange Sorbents. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15470-15477. [PMID: 36265138 DOI: 10.1021/acs.est.1c08345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Anion-exchange (AE) sorbents are gaining in popularity for the remediation of anionic per- and polyfluoroalkyl substances (PFAS) in water. However, it is unclear how hydrophobic and electrostatic interactions contribute to anionic PFAS retention. The goal of this study was to understand the effects of PFAS chain length and head group on electrostatic interactions between PFAS and an aminopropyl AE phase. Liquid chromatography-mass spectrometry (LC-MS) was used with an aminopropyl AE guard column to find relative retention times. The average electrostatic potential (EPavg) of each PFAS was calculated, which correlated positively with the PFAS chromatographic retention time, demonstrating the value of EPavg as a proxy for predicting electrostatic interactions between PFAS and the aminopropyl AE phase. The order of greatest to lowest PFAS AE affinity for an aminopropyl column based on chromatographic retention times and electrostatic interactions was n:3 fluorotelomer carboxylic acids (n:3 FtAs) > n:2 fluorotelomer carboxylic acids (n:2 FtAs) > perfluoroalkyl carboxylates (PFCAs) > perfluoroalkyl sulfonamides (FASAs) ∼ n:2 fluorotelomer sulfonates (n:2 FtSs) > perfluoroalkyl sulfonates (PFSAs). This study introduces a methodology for qualitatively characterizing electrostatic interactions between PFAS and AE phases and highlights that electrostatic interactions alone cannot explain the affinity of PFAS for AE resins in water treatment/remediation scenarios.
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Affiliation(s)
- Bethany A Parker
- Department of Chemistry, Oregon State University, Corvallis, Oregon97331, United States
| | - Detlef R U Knappe
- Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, North Carolina27695-8201, United States
| | - Ivan A Titaley
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon97331, United States
| | - Thomas A Wanzek
- Department of Crop and Soil Science, Oregon State University, Corvallis, Oregon97331, United States
| | - Jennifer A Field
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon97331, United States
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12
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Gauthier JR, Mabury SA. Noise-Reduced Quantitative Fluorine NMR Spectroscopy Reveals the Presence of Additional Per- and Polyfluorinated Alkyl Substances in Environmental and Biological Samples When Compared with Routine Mass Spectrometry Methods. Anal Chem 2022; 94:3278-3286. [PMID: 35148065 DOI: 10.1021/acs.analchem.1c05107] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Per- and polyfluorinated alkyl substances (PFAS) are ubiquitous throughout the environment. Analysis of PFAS is commonly performed using both targeted and nontargeted mass spectrometry methods. However, it has been demonstrated that measurements of fluorinated compounds in the environment by mass spectrometry often fall short of the total fluorine concentration. In the present study, we employ a 19F NMR technique, which is capable of detailing fluorinated compounds in a sample while providing both quantitative and structural information. Inclusion of a noise-reduction strategy involving the acquisition of arrays of spectra with an increasing number of transients addresses the sensitivity challenges of environmental nuclear magnetic resonance (NMR), improving signal to noise. When this technique is applied to environmental and biological samples including rainwater, lake water, wastewater effluent, serum, and urine, the presence of PFAS, which may have been missed by routine mass spectrometric methods, is revealed. Important resonances in the 19F NMR spectrum such as that of trifluoroacetic acid are brought above the limit of quantification in all samples, allowing detection limits as low as 389 pg/L in rainwater. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, which was used to analyze 47 PFAS compounds, accounts for only 3.7-27% of the total fluorine concentration as determined by the NMR strategy in the present study.
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Affiliation(s)
- Jeremy R Gauthier
- Department of Chemistry, Lash Miller Chemical Labs, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
| | - Scott A Mabury
- Department of Chemistry, Lash Miller Chemical Labs, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
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13
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Fedorenko M, Alesio J, Fedorenko A, Slitt A, Bothun GD. Dominant entropic binding of perfluoroalkyl substances (PFASs) to albumin protein revealed by 19F NMR. CHEMOSPHERE 2021; 263:128083. [PMID: 33297081 PMCID: PMC8479757 DOI: 10.1016/j.chemosphere.2020.128083] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 05/05/2023]
Abstract
Mechanistic insight into protein binding by poly- and perfluoroalkyl substances (PFASs) is critical to understanding how PFASs distribute and accumulate within the body and to developing predictive models within and across classes of PFASs. Fluorine nuclear magnetic resonance spectroscopy (19F NMR) has proven to be a powerful, yet underutilized tool to study PFAS binding; chemical shifts of each fluorine group reflect the local environment along the length of the PFAS molecule. Using bovine serum albumin (BSA), we report dissociation constants, Kd, for four common PFASs well below reported critical micelle concentrations (CMCs) - perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), and perfluorooctanesulfonic acid (PFOS) - as a function of temperature in phosphate buffered saline. Kd values were determined based on the difluoroethyl group adjacent to the anionic headgroups and the terminal trifluoromethyl groups. Our results indicate that the hydrophobic tails exhibit greater binding affinity relative to the headgroup, and that the binding affinities are generally consistent with previous results showing that greater PFAS hydrophobicity leads to greater protein binding. However, the binding mechanism was dominated by entropic hydrophobic interactions attributed to desolvation of the PFAS tails within the hydrophobic cavities of the protein and on the surface of the protein. In addition, PFNA appears to form hemimicelles on the protein surfaces below reported CMC values. This work provides a renewed approach to utilizing 19F NMR for PFAS-protein binding studies and a new perspective on the role of solvent entropy.
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Affiliation(s)
- Michael Fedorenko
- Department of Chemical Engineering, University of Rhode Island, 2 East Alumni Ave, Kingston, RI, 02881, USA
| | - Jessica Alesio
- Department of Chemical Engineering, University of Rhode Island, 2 East Alumni Ave, Kingston, RI, 02881, USA
| | - Anatoliy Fedorenko
- Department of Chemical Engineering, University of Rhode Island, 2 East Alumni Ave, Kingston, RI, 02881, USA
| | - Angela Slitt
- Department of Biomedical & Pharmaceutical Sciences, University of Rhode Island, 7 Greenhouse Rd, Kingston, RI, 02881, USA
| | - Geoffrey D Bothun
- Department of Chemical Engineering, University of Rhode Island, 2 East Alumni Ave, Kingston, RI, 02881, USA.
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14
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Allendorf F, Berger U, Goss KU, Ulrich N. Partition coefficients of four perfluoroalkyl acid alternatives between bovine serum albumin (BSA) and water in comparison to ten classical perfluoroalkyl acids. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:1852-1863. [PMID: 31475719 DOI: 10.1039/c9em00290a] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Perfluoroalkyl acids (PFAAs) are persistent, ubiquitous environmental contaminants and their long-chain representatives are bioaccumulative. The phase-out of these compounds (e.g. PFOA and PFOS) shifted the production to alternatives. However, little is known about the bioaccumulative behaviour of the alternatives, which are still highly fluorinated. PFAAs are predominantly detected in blood, where they bind to the transport protein serum albumin. This sorption can be described by the albumin/water partition coefficient. It is unclear whether the partition coefficients of the alternatives are lower than or in the same range as those of classical PFAAs. We determined albumin/water partition coefficients for seven perfluoroalkyl carboxylates, three perfluoroalkane sulfonates and four alternatives by dialysis experiments in a physiologically representative system. Quantification was done by LC-MS/MS and a mass balance approach. Logarithmic albumin/water partition coefficients for PFAAs range from 2.8 to 4.8 [Lwater kgalbumin-1] and increase with increasing chain length. Perfluorinated sulfonates sorb more strongly than their carboxylate counterparts. The albumin/water partition coefficients for the alternatives (HFPO-DA, DONA, 9Cl-PF3ONS and PFECHS) are in the same range as for classical PFAAs. Structural modifications such as the introduction of ether groups into the chain do not reduce sorption to albumin, whereas the chlorine atom in 9Cl-PF3ONS seems to even increase the sorption to albumin. We further investigated whether the sorption strength could be affected in the presence of medium- or long-chain fatty acids. Binding competition between medium-chain fatty acids and PFAAs appeared to be possible. However, the presence of physiologically more relevant long-chain fatty acids should not alter the albumin/water partition coefficients of PFAAs.
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Affiliation(s)
- Flora Allendorf
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, D-04318 Leipzig, Germany.
| | - Urs Berger
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Kai-Uwe Goss
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, D-04318 Leipzig, Germany. and Institute of Chemistry, University of Halle-Wittenberg, Kurt-Mothes-Strasse 2, D-06120 Halle, Germany
| | - Nadin Ulrich
- Department of Analytical Environmental Chemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, D-04318 Leipzig, Germany.
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15
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Ning C, Ma H, Pedersen CM, Chang H, Wang Y, Qiao Y. Interaction between environmental contaminant PFOA and PAMAM in water: 19F and 1H NMR studies. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.03.057] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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16
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Campos Pereira H, Ullberg M, Kleja DB, Gustafsson JP, Ahrens L. Sorption of perfluoroalkyl substances (PFASs) to an organic soil horizon - Effect of cation composition and pH. CHEMOSPHERE 2018; 207:183-191. [PMID: 29793030 DOI: 10.1016/j.chemosphere.2018.05.012] [Citation(s) in RCA: 124] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 05/28/2023]
Abstract
Accurate prediction of the sorption of perfluoroalkyl substances (PFASs) in soils is essential for environmental risk assessment. We investigated the effect of solution pH and calculated soil organic matter (SOM) net charge on the sorption of 14 PFASs onto an organic soil as a function of pH and added concentrations of Al3+, Ca2+ and Na+. Often, the organic C-normalized partitioning coefficients (KOC) showed a negative relationship to both pH (Δlog KOC/ΔpH = -0.32 ± 0.11 log units) and the SOM bulk net negative charge (Δlog KOC = -1.41 ± 0.40 per log unit molc g-1). Moreover, perfluorosulfonic acids (PFSAs) sorbed more strongly than perfluorocarboxylic acids (PFCAs) and the PFAS sorption increased with increasing perfluorocarbon chain length with 0.60 and 0.83 log KOC units per CF2 moiety for C3-C10 PFCAs and C4, C6, and C8 PFSAs, respectively. The effects of cation treatment and SOM bulk net charge were evident for many PFASs with low to moderate sorption (C5-C8 PFCAs and C6 PFSA). However for the most strongly sorbing and most long-chained PFASs (C9-C11 and C13 PFCAs, C8 PFSA and perfluorooctane sulfonamide (FOSA)), smaller effects of cations were seen, and instead sorption was more strongly related to the pH value. This suggests that the most long-chained PFASs, similar to other hydrophobic organic compounds, are preferentially sorbed to the highly condensed domains of the humin fraction, while shorter-chained PFASs are bound to a larger extent to humic and fulvic acid, where cation effects are significant.
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Affiliation(s)
- Hugo Campos Pereira
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7014, SE-75007 Uppsala, Sweden.
| | - Malin Ullberg
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7014, SE-75007 Uppsala, Sweden
| | - Dan Berggren Kleja
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7014, SE-75007 Uppsala, Sweden; Swedish Geotechnical Institute, Kornhamnstorg 61, SE-11127 Stockholm, Sweden
| | - Jon Petter Gustafsson
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7014, SE-75007 Uppsala, Sweden; Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, 10044 Stockholm, Sweden
| | - Lutz Ahrens
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, SE-75007 Uppsala, Sweden
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17
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Jin H, Zhang Y, Jiang W, Zhu L, Martin JW. Isomer-Specific Distribution of Perfluoroalkyl Substances in Blood. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:7808-7815. [PMID: 27295125 DOI: 10.1021/acs.est.6b01698] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Perfluoroalkyl substances (PFASs) such as perfluorohexanesulfonate (PFHxS), perfluorooctanoate (PFOA), perfluorooctanesulfonate (PFOS) and PFOS-precursors are routinely measured in human plasma and serum, but their relative abundance in the blood cell fraction has not been carefully examined, particularly at the isomer-specific level. Human plasma and whole blood were collected and partitioning behaviors of PFASs and their isomers between plasma and blood cells were investigated. In human samples, mass fraction in plasma (Fp) for PFASs increased among perfluoroalkyl carboxylates as the carbon chain length increased from C6 (mean 0.24) to C11 (0.87), indicating preference for the plasma fraction with increasing chain length. However, among perfluoroalkyl sulfonates, PFHxS (mean 0.87) had a slightly higher Fp than PFOS (0.85). In vitro assays with spiked Sprague-Dawley rat blood were also conducted, and the results showed that PFOS-precursors had lower Fp values than perfluoroalkyl acids, with perfluoroctanesulfonamide having the lowest Fp (mean 0.24). Consistently, linear isomers of PFOS and PFOS-precursors had lower mean Fp than their corresponding total branched isomers. Multiplying by a factor of 2 is not a reasonable method to convert from whole blood to plasma PFAS concentrations, and current ratios could be used as more accurate conversion factors.
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Affiliation(s)
- Hangbiao Jin
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin, P.R. China
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, University of Alberta , Edmonton, Alberta Canada T6G 2G3
| | - Yifeng Zhang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin, P.R. China
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, University of Alberta , Edmonton, Alberta Canada T6G 2G3
| | - Weiwei Jiang
- South China Institute of Environmental Science , Ministry of Environmental Protection, Guangzhou, P.R. China
| | - Lingyan Zhu
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University , Tianjin, P.R. China
| | - Jonathan W Martin
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, University of Alberta , Edmonton, Alberta Canada T6G 2G3
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18
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Yurdacan M, Franke O, Hogen-Esch T. Nanoindentation of Films of Perfluorotridecyl, Perfluorodecyl, and Perfluoroheptyl End-Functionalized Polystyrene at the Micron Scale. MACROMOL CHEM PHYS 2016. [DOI: 10.1002/macp.201500328] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Merve Yurdacan
- Department of Chemistry and Loker; Hydrocarbon Research Institute; University of Southern California; Los Angeles CA 90089-1661 USA
| | - Oliver Franke
- Department of Aerospace and Mechanical Engineering; University of Southern California; Los Angeles CA 90089-1661 USA
| | - Thieo Hogen-Esch
- Department of Chemistry and Loker; Hydrocarbon Research Institute; University of Southern California; Los Angeles CA 90089-1661 USA
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19
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Sansotera M, Persico F, Rizzi V, Panzeri W, Pirola C, Bianchi CL, Mele A, Navarrini W. The effect of oxygen in the photocatalytic oxidation pathways of perfluorooctanoic acid. J Fluor Chem 2015. [DOI: 10.1016/j.jfluchem.2015.06.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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20
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21
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Krafft MP, Riess JG. Selected physicochemical aspects of poly- and perfluoroalkylated substances relevant to performance, environment and sustainability-part one. CHEMOSPHERE 2015; 129:4-19. [PMID: 25245564 DOI: 10.1016/j.chemosphere.2014.08.039] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 08/10/2014] [Accepted: 08/13/2014] [Indexed: 05/27/2023]
Abstract
The elemental characteristics of the fluorine atom tell us that replacing an alkyl chain by a perfluoroalkyl or polyfluorinated chain in a molecule or polymer is consequential. A brief reminder about perfluoroalkyl chains, fluorocarbons and fluorosurfactants is provided. The outstanding, otherwise unattainable physicochemical properties and combinations thereof of poly and perfluoroalkyl substances (PFASs) are outlined, including extreme hydrophobic and lipophobic character; thermal and chemical stability in extreme conditions; remarkable aptitude to self-assemble into sturdy thin repellent protecting films; unique spreading, dispersing, emulsifying, anti-adhesive and levelling, dielectric, piezoelectric and optical properties, leading to numerous industrial and technical uses and consumer products. It was eventually discovered, however, that PFASs with seven or more carbon-long perfluoroalkyl chains had disseminated in air, water, soil and biota worldwide, are persistent in the environment and bioaccumulative in animals and humans, raising serious health and environmental concerns. Further use of long-chain PFASs is environmentally not sustainable. Most leading manufacturers have turned to shorter four to six carbon perfluoroalkyl chain products that are not considered bioaccumulative. However, many of the key performances of PFASs decrease sharply when fluorinated chains become shorter. Fluorosurfactants become less effective and less efficient, provide lesser barrier film stability, etc. On the other hand, they remain as persistent in the environment as their longer chain homologues. Surprisingly little data (with considerable discrepancies) is accessible on the physicochemical properties of the PFASs under examination, a situation that requires consideration and rectification. Such data are needed for understanding the environmental and in vivo behaviour of PFASs. They should help determine which, for which uses, and to what extent, PFASs are environmentally sustainable.
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Affiliation(s)
- Marie Pierre Krafft
- Institut Charles Sadron (CNRS UPR 22), Université de Strasbourg, 23 rue du Loess, 67034 Strasbourg Cedex 2, France.
| | - Jean G Riess
- Harangoutte Institute, 68160 Sainte Croix-aux-Mines, France
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23
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24
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Affiliation(s)
- Khaleel I. Assaf
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
| | - Werner M. Nau
- School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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25
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Muñoz BK, Ojo WS, Jacob K, Romero N, Vendier L, Despagnet-Ayoub E, Etienne M. Perfluorinated 1H-indazoles and hydrotris(indazol-1-yl)borates. Supramolecular organization and a new synthetic procedure to form scorpionate ligands. NEW J CHEM 2014. [DOI: 10.1039/c4nj00136b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The molecular and supramolecular structures of new perfluorinated indazoles and hydrotris(indazolyl)borates reveal various types of intra- and intermolecular interactions and organizations.
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Affiliation(s)
- Bianca K. Muñoz
- CNRS
- LCC (Laboratoire de Chimie de Coordination)
- F-31077 Toulouse Cedex 4, France
- Université de Toulouse
- UPS
| | - Wilfried-Solo Ojo
- CNRS
- LCC (Laboratoire de Chimie de Coordination)
- F-31077 Toulouse Cedex 4, France
- Université de Toulouse
- UPS
| | - Kane Jacob
- CNRS
- LCC (Laboratoire de Chimie de Coordination)
- F-31077 Toulouse Cedex 4, France
- Université de Toulouse
- UPS
| | - Nuria Romero
- CNRS
- LCC (Laboratoire de Chimie de Coordination)
- F-31077 Toulouse Cedex 4, France
- Université de Toulouse
- UPS
| | - Laure Vendier
- CNRS
- LCC (Laboratoire de Chimie de Coordination)
- F-31077 Toulouse Cedex 4, France
- Université de Toulouse
- UPS
| | - Emmanuelle Despagnet-Ayoub
- CNRS
- LCC (Laboratoire de Chimie de Coordination)
- F-31077 Toulouse Cedex 4, France
- Université de Toulouse
- UPS
| | - Michel Etienne
- CNRS
- LCC (Laboratoire de Chimie de Coordination)
- F-31077 Toulouse Cedex 4, France
- Université de Toulouse
- UPS
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Lin H, Niu J, Xu J, Huang H, Li D, Yue Z, Feng C. Highly efficient and mild electrochemical mineralization of long-chain perfluorocarboxylic acids (C9-C10) by Ti/SnO2-Sb-Ce, Ti/SnO2-Sb/Ce-PbO2, and Ti/BDD electrodes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:13039-13046. [PMID: 24164589 DOI: 10.1021/es4034414] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The electrochemical mineralization of environmentally persistent long-chain perfluorinated carboxylic acids (PFCAs), i.e., perfluorononanoic acid (C8F17COOH, PFNA) and perfluorodecanoic acid (C9F19COOH, PFDA) was investigated in aqueous solutions (0.25 mmol L(-1)) over Ti/SnO2-Sb-Ce (SnO2), Ti/SnO2-Sb/Ce-PbO2 (PbO2), and Ti/BDD (BDD) anodes under galvanostatic control at room temperature. Based on PFCA decay rate, total organic carbon (TOC) reduction, defluorination ratio, safety, and energy consumption, the performance of PbO2 electrode was comparable with that of BDD electrode. After 180 min electrolysis, the PFNA removals on BDD and PbO2 electrodes were 98.7 ± 0.4% and 97.1 ± 1.0%, respectively, while the corresponding PFDA removals were 96.0 ± 1.4% and 92.2 ± 1.9%. SnO2 electrode yielded lower PFCA removals and led to notable secondary pollution by Sb ions. The primary mineralization product, F(-), as well as trace amounts of intermediate PFCAs with shortened chain lengths, were detected in aqueous solution after electrolysis. On the basis of these results, a degradation mechanism including three potential routes is proposed: via formation of short-chain PFCAs by stepwise removal of CF2; direct mineralization to CO2 and HF; conversion to volatile fluorinated organic compounds. The results presented here demonstrate that electrochemical technique exhibits high efficiency in mineralizing PFNA and PFDA under mild conditions, and is promising for the treatment of long-chain PFCAs in wastewater.
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Affiliation(s)
- Hui Lin
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University , Beijing 100875, P.R. China
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Karoyo AH, Sidhu P, Wilson LD, Hazendonk P. Characterization and dynamic properties for the solid inclusion complexes of β-cyclodextrin and perfluorooctanoic acid. J Phys Chem B 2013. [PMID: 23713518 DOI: 10.1021/jp502325e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The structural characterization and dynamic properties of solid-state inclusion complexes (ICs) formed between β-cyclodextrin (β-CD; host) and perfluorooctanoic acid (PFOA; guest) were investigated using (13)C NMR spectroscopy. The 1:1 and 2:1 host/guest solid-state complexes were prepared using a modified dissolution method to obtain complexes with high phase purity. These complexes were further characterized using differential scanning calorimetry (DSC), FT-IR spectroscopy, powder X-ray diffraction (PXRD), (19)F directpolarization (DP), and (13)C cross-polarization (CP) with magic-angle spinning (MAS) NMR spectroscopy. The (19)F → (13)C CP results provided unequivocal support for the formation of well-defined inclusion compounds. The phase purity of the complexes formed between β-CD and PFOA were assessed using the (19)F DP NMR technique at variable temperature (VT) and MAS at 20 kHz. The complexes were found to be of high phase purity when prepared in accordance with the modified dissolution method. The motional dynamics of the guest in the solid complexes were assessed using T1/T2/T1ρ relaxation NMR methods at ambient and VT conditions. The relaxation data revealed reliable and variable guest dynamics for the 1:1 versus 2:1 complexes at the VTs investigated. The motional dynamics of the guest molecules involve an ensemble of axial motions of the whole chain and 120° rotational jumps of the methyl (CF3) group at the termini of the perfluorocarbon chain. The axial and rotational dynamics of the guest in the 1:1 and 2:1 complexes differ in distribution and magnitude in accordance with the binding geometry of the guest within the host.
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Affiliation(s)
- Abdalla H Karoyo
- Department of Chemistry, University of Saskatchewan, Saskatoon, SK S7N 5C9, Canada
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Functionalization of Non-activated CH Bonds of Alkanes: An Effective and Recyclable Catalytic System Based on Fluorinated Silver Catalysts and Solvents. Chemistry 2012. [DOI: 10.1002/chem.201203566] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Bischel HN, Macmanus-Spencer LA, Zhang C, Luthy RG. Strong associations of short-chain perfluoroalkyl acids with serum albumin and investigation of binding mechanisms. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2011; 30:2423-30. [PMID: 21842491 DOI: 10.1002/etc.647] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2011] [Revised: 05/09/2011] [Accepted: 07/23/2011] [Indexed: 05/22/2023]
Abstract
Interactions of perfluoroalkyl acids (PFAAs) with tissue and serum proteins likely contribute to their tissue distribution and bioaccumulation patterns. Protein-water distribution coefficients (K(PW) ) based on ligand associations with bovine serum albumin (BSA) as a model protein were recently proposed as biologically relevant parameters to describe the environmental behavior of PFAAs, yet empirical data on such protein binding behavior are limited. In the present study, associations of perfluoroalkyl carboxylates (PFCAs) with two to 12 carbons (C₂-C₁₂) and perfluoroalkyl sulfonates with four to eight carbons (C₄, C₆, and C₈) with BSA are evaluated at low PFAA:albumin mole ratios and various solution conditions using equilibrium dialysis, nanoelectrospray ionization mass spectrometry, and fluorescence spectroscopy. Log K(PW) values for C₄ to C₁₂ PFAAs range from 3.3 to 4.3. Affinity for BSA increases with PFAA hydrophobicity but decreases from the C₈ to C₁₂ PFCAs, likely due to steric hindrances associated with longer and more rigid perfluoroalkyl chains. The C₄-sulfonate exhibits increased affinity relative to the equivalent chain-length PFCA. Fluorescence titrations support evidence that an observed dependence of PFAA-BSA binding on pH is attributable to conformational changes in the protein. Association constants determined for perfluorobutanesulfonate and perfluoropentanoate with BSA are on the order of those for long-chain PFAAs (K(a) ∼10⁶/M), suggesting that physiological implications of strong binding to albumin may be important for short-chain PFAAs.
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Affiliation(s)
- Heather N Bischel
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California, USA
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Karoyo AH, Borisov AS, Wilson LD, Hazendonk P. Formation of Host-Guest Complexes of β-Cyclodextrin and Perfluorooctanoic Acid. J Phys Chem B 2011; 115:9511-27. [DOI: 10.1021/jp110806k] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Abdalla H. Karoyo
- University of Saskatchewan, Department of Chemistry, Saskatoon, SK, S7N 5C9, Canada
| | - Alex S. Borisov
- University of Lethbridge, Department of Chemistry and Biochemistry, Lethbridge, AB, Canada
| | - Lee D. Wilson
- University of Saskatchewan, Department of Chemistry, Saskatoon, SK, S7N 5C9, Canada
| | - Paul Hazendonk
- University of Lethbridge, Department of Chemistry and Biochemistry, Lethbridge, AB, Canada
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Simpson AJ, McNally DJ, Simpson MJ. NMR spectroscopy in environmental research: from molecular interactions to global processes. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2011; 58:97-175. [PMID: 21397118 DOI: 10.1016/j.pnmrs.2010.09.001] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Accepted: 09/17/2010] [Indexed: 05/30/2023]
Affiliation(s)
- André J Simpson
- Environmental NMR Center, Department of Chemistry, University of Toronto, Ontario, Canada.
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Abbandonato G, Catalano D, Marini A. Aggregation of perfluoroctanoate salts studied by 19F NMR and DFT calculations: counterion complexation, poly(ethylene glycol) addition, and conformational effects. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:16762-16770. [PMID: 20883045 DOI: 10.1021/la102578k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The aggregation of perfluoroctanoate salts in H(2)O is studied by (19)F NMR on solutions of LiPFO, NaPFO, and CsPFO, without and with the addition of two poly(ethylene glycol) (PEG) oligomers of molecular weight 1500 and 3400 Da, respectively, and with the addition of suitable crown ethers. The (19)F chemical shift (cs) trends are monitored, at 25 °C, in a concentration range including the critical micellar concentration (cmc) or, in the presence of PEG, the critical aggregation concentration (cac). The cac values in the samples with PEG are lower than the cmc values of the corresponding samples without PEG; moreover, the (19)F cs trends above the cac and above the polymer saturation concentration reveal and help to explain some peculiarities of the aggregation process of PEG on PFO micelles, which, in the first step, seems to occur while the surfactant concentration in water is still increasing. Also in LiPFO/H(2)O or NaPFO/H(2)O solutions containing 12-crown-4 or 15-crown-5 ethers, suitable to complex Li(+) or Na(+) ions, respectively, the cmc decreases. On the other hand, the micellization process in the presence of crown ethers does not show other peculiarities. The prevailing conformations of the PFO chain are discussed on the basis of quantum-mechanical calculations. The theoretical chemical shifts were computed at the DFT level of theory, taking into account the effects of the environment by means of the IEF-PCM method. The helical structure is the most stable one, but anti conformations are easily accessible, in both the aqueous and fluorinated environment. The comparison between computed and experimental chemical shifts indicates that anti conformations are more important in the micelles than in water and in CsPFO micelles than in LiPFO or NaPFO ones.
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Affiliation(s)
- Gerardo Abbandonato
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via Risorgimento 35, 56126 Pisa, Italy
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D'eon JC, Simpson AJ, Kumar R, Baer AJ, Mabury SA. Determining the molecular interactions of perfluorinated carboxylic acids with human sera and isolated human serum albumin using nuclear magnetic resonance spectroscopy. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2010; 29:1678-88. [PMID: 20821619 DOI: 10.1002/etc.204] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Perfluorooctanoate (PFOA) is ubiquitous in North American human sera and has a serum half-life of 3.5 years in humans. The molecular interactions that lead to the bioaccumulation of these hydrophobic and lipophobic molecules in human blood are not well understood. Perfluorohexanoic acid (PFHxA) and PFOA were used as model perfluorinated carboxylic acids (PFCAs) to characterize the major site of PFCA interaction in human sera. Using novel heteronuclear saturation transfer difference nuclear magnetic resonance spectroscopy experiments, human serum albumin (HSA) was identified as the major site of interaction for both PFHxA and PFOA in human sera. Heteronuclear single quantum coherence nuclear magnetic resonance experiments were then performed to interrogate site-specific interactions of PFHxA and PFOA with isolated HSA. Perfluorohexanoic acid was found to bind specifically to Sudlow's drug-binding site II, whereas PFOA interacted preferentially with Sudlow's drug-binding site I at the lower concentration, with additional interactions developing at the higher concentration. These experiments highlight the utility of nuclear magnetic resonance spectrometry as a tool to observe the in situ interactions of chemical contaminants with biological systems. Both PFCAs displaced the endogenous HSA ligand oleic acid at concentrations lower than observed for the drugs ibuprofen and phenylbutazone, which are established HSA ligands. Interactions between PFCAs and HSA may affect the pharmacokinetics and distribution of fatty acids and certain drugs in the human body and warrant further investigation.
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Affiliation(s)
- Jessica C D'eon
- Department of Chemistry, University of Toronto, Toronto, Ontario, M5S 3H6 Canada
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Liu Z, Goddard JD. Predictions of the Fluorine NMR Chemical Shifts of Perfluorinated Carboxylic Acids, CnF2n+1COOH (n = 6−8). J Phys Chem A 2009; 113:13921-31. [DOI: 10.1021/jp9078037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zizhong Liu
- Department of Chemistry, University of Guelph, Guelph, Ontario, Canada N1G 2W1, and Chemistry and Environment Science College, Inner Mongolia Normal University, Huhhot, Inner Mongolia, China 010022
| | - John D. Goddard
- Department of Chemistry, University of Guelph, Guelph, Ontario, Canada N1G 2W1, and Chemistry and Environment Science College, Inner Mongolia Normal University, Huhhot, Inner Mongolia, China 010022
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35
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Rayne S, Forest K, Friesen KJ. Computational approaches may underestimate pK(a) values of longer-chain perfluorinated carboxylic acids: Implications for assessing environmental and biological effects. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2009; 44:317-326. [PMID: 19184697 DOI: 10.1080/10934520802659620] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Acidity constants were calculated using the semiempirical PM6 pK(a) estimation method for all C(2) through C(9) perfluoroalkyl carboxylate (PFCA) congeners and the straight-chain C(10) through C(13) isomers. According to the PM6 estimates, the linear congeners within each PFCA homologue group have the highest pK(a) values by up to 6 units depending on the degree of branching in the perfluoroalkyl chain. In general, the higher the degree of branching in the perfluoroalkyl chain within a homologue group, the lower the estimated pK(a) value. When the branching is closest to the terminal carboxylate group, the effect on the calculated pK(a) is greatest. Although the PM6 calculated pK(a) values agree well with previously reported estimates for selected linear PFCA congeners using the SPARC and COSMOtherm approaches, all computational approaches only show good agreement with reported experimental values for short chain PFCAs (C(2) through C(5)). Increasing divergences are observed between calculated and experimental results by up to several pK(a) units as the perfluoroalkyl chain length increases beyond C(5). The findings demonstrate a need for additional experimental pK(a) measurements for an expanded set of both linear and branched PFCA congeners to confirm previous experimental reports that are potentially in error, and upon which to calibrate existing computational methods and environmental, toxicological, and waste treatment method models.
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Affiliation(s)
- Sierra Rayne
- Department of Chemistry, The University of Winnipeg, Winnipeg, MB, Canada.
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37
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Jing P, Rodgers PJ, Amemiya S. High lipophilicity of perfluoroalkyl carboxylate and sulfonate: implications for their membrane permeability. J Am Chem Soc 2009; 131:2290-6. [PMID: 19170492 PMCID: PMC2664102 DOI: 10.1021/ja807961s] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Here we report on remarkably high lipophilicity of perfluoroalkyl carboxylate and sulfonate. A lipophilic nature of this emerging class of organic pollutants has been hypothesized as an origin of their bioaccumulation and toxicity. Both carboxylate and sulfonate, however, are considered hydrophilic while perfluroalkyl groups are not only hydrophobic but also oleophobic. Partition coefficients of a homologous series of perfluoroalkyl and alkyl carboxylates between water and n-octanol were determined as a measure of their lipophilicity by ion-transfer cyclic voltammetry. Very similar lipophilicity of perfluoroalkyl and alkyl chains with the same length is demonstrated experimentally for the first time by fragment analysis of the partition coefficients. This finding is important for pharmaceutical and biomedical applications of perfluoroalkyl compounds. Interestingly, approximately 2 orders of magnitude higher lipophilicity of a perfluoroalkyl carboxylate or sulfonate in comparison to its alkyl counterpart is ascribed nearly exclusively to their oxoanion groups. The higher lipophilicity originates from a strong electron-withdrawing effect of the perfluoroalkyl group on the adjacent oxoanion group, which is weakly hydrated to decrease its hydrophilicity. In fact, the inductive effect is dramatically reduced for a fluorotelomer with an ethylene spacer between perfluorohexyl and carboxylate groups, which is only as lipophilic as its alkyl counterpart, nonanoate, and is 400 times less lipophilic than perfluorononanoate. The high lipophilicity of perfluoroalkyl carboxylate and sulfonate implies that their permeation across such a thin lipophilic membrane as a bilayer lipid membrane is limited by their transfer at a membrane/water interface. The limiting permeability is lower and less dependent on their lipophilicity than the permeability controlled by their diffusion in the membrane interior as assumed in the classical solubility-diffusion model.
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Affiliation(s)
- Ping Jing
- Department of Chemistry, University of Pittsburgh, Pennsylvania 15260, USA
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38
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Burns DC, Ellis DA, Li H, McMurdo CJ, Webster E. Experimental pKa determination for perfluorooctanoic acid (PFOA) and the potential impact of pKa concentration dependence on laboratory-measured partitioning phenomena and environmental modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:9283-8. [PMID: 19174905 DOI: 10.1021/es802047v] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
An accurately measured equilibrium acid dissociation constant (pKa) is essential for understanding and predicting the fate of perfluorocarboxylic acids (PFCAs) in the environment. The aqueous pKa of perfluorooctanoic acid (PFOA) has been determined potentiometrically using a standard water-methanol mixed solvent approach and was found to be 3.8 +/- 0.1. The acidity of PFOA is thus considerably weaker than its shorter-chain PFCA homologues. This was attributed to differences in molecular and electronic structure, coupled with solvation effects. The pKa of PFOA was suppressed to approximately 2.3 at higher concentrations because of the aggregation of perfluorooctanoate (PFO). Often, PFCA partion coefficients are determined at concentrations above those found in the environment. Thus, it was suggested that a pKa correction factor, which accounts for this concentration-dependent shift in acid/base equilibrium, should be applied to PFCA partition efficients before they are implemented in environmental fate models. A pKa of 3.8 +/- 0.1 suggests that a considerable concentration of the PFCA exists as the neutral species in the aqueous environment for example, in typical Ontario rainwater, it is approximately 17%. Transport, fate, and partitioning models have often ignored the presence this species completely. The environmental dissemination of PFCAs could, in part, be explained by considering the role of the neutral species.
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Affiliation(s)
- Darcy C Burns
- Department of Chemistry, Centre for Environmental Modelling and Chemistry, Trent University, 1600 West Bank Drive, Peterborough, Ontario, K9J 7B8 Canada
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39
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Arsenault G, Chittim B, Gu J, McAlees A, McCrindle R, Robertson V. Separation and fluorine nuclear magnetic resonance spectroscopic (19F NMR) analysis of individual branched isomers present in technical perfluorooctanesulfonic acid (PFOS). CHEMOSPHERE 2008; 73:S53-9. [PMID: 18440586 DOI: 10.1016/j.chemosphere.2007.06.096] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/14/2007] [Indexed: 05/22/2023]
Abstract
The production of perfluoroalkylsulfonate (PFOS) derivatives from linear alkyl precursors using electrochemical fluorination is not a clean process but, instead, gives complex mixtures. This study reports the isolation and (19)F NMR characterization of eleven perfluorooctanesulfonate isomers from a commercial mixture. This allowed the quantification of the individual CF(3) branched isomers that predominate in technical PFOS.
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Affiliation(s)
- Gilles Arsenault
- Wellington Laboratories Inc., Research Division, Guelph, Ontario, Canada N1G 3M5.
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40
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Mountain RD, Lippa KA. Solvation of Perfluorooctane and Octane in Water, Methanol, Acetonitrile, and Aqueous Mixtures of Methanol and Acetonitrile. J Phys Chem B 2008; 112:7785-93. [DOI: 10.1021/jp0774802] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Raymond D. Mountain
- Physical and Chemical Properties Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, and Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8392
| | - Katrice A. Lippa
- Physical and Chemical Properties Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, and Analytical Chemistry Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8392
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41
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Agouridas V, Blazejewski JC, Cleeren A, Laïos I, Leclercq G, Magnier E. Fluorous tolerance of the estrogen receptor alpha as probed by 11-polyfluoroalkylestradiol derivatives. Steroids 2008; 73:320-7. [PMID: 18177682 DOI: 10.1016/j.steroids.2007.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Revised: 09/11/2007] [Accepted: 11/15/2007] [Indexed: 01/22/2023]
Abstract
The concern of this work was to try to delineate factors, inherent to fluorination, susceptible to influence estradiol binding to the estrogen receptor alpha (ERalpha). For this purpose, fluorinated chains were linked at 11beta position of the steroid (i.e., C(6)F(13), CH(2)CH(2)C(4)F(9), CH(2)CH(2)C(8)F(17)). Relative binding affinity (RBA) for ERalpha of these compounds and of other related fluorinated derivatives was compared to those of non-fluorinated analogs. Despite being relatively well accepted by the receptor, investigated compounds exhibited lower RBA values at 0 degrees C than their non-fluorinated counterparts. Nevertheless, heavily fluorinated chains were tolerated in so far as they are not too long (C-4) and insulated from the steroidal core by a two methylene spacer unit. Increase of the temperature of our binding assay (25 degrees C) failed to change the RBA values of two selected polyfluorohexyl derivatives while it drastically enhanced the value of the corresponding non-fluorinated analogs. Rigidity of the chain induced by fluorination as well as the oleophilic (fluorophobic) nature of the estradiol binding cavity of ERalpha is proposed to explain these properties.
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Affiliation(s)
- Vangelis Agouridas
- Institut Lavoisier de Versailles (ILV), UMR CNRS 8180, Université de Versailles, Versailles Cedex, France
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42
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Tsuji M, Inoue T, Shibata O. Purification and thermal analysis of perfluoro-n-alkanoic acids. Colloids Surf B Biointerfaces 2008; 61:61-5. [PMID: 17719754 DOI: 10.1016/j.colsurfb.2007.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Revised: 07/07/2007] [Accepted: 07/14/2007] [Indexed: 11/22/2022]
Abstract
Purification of perfluoro-n-alkanoic acids (C(n)F(2n+1)COOH, n=7, 9, 11, 13, 15 and 17) was made by repeated recrystallizations from n-hexane/acetone mixed solvent, and their purity was found to be more than 99.5% by GC-MS, NMR, and elemental analysis. The thermal behaviors such as melting point and enthalpy change of fusion were investigated using differential scanning calorimetry (DSC). The melting point monotonously increased with increasing carbon number (n) of the acids, while the enthalpy change showed irregularity at n=14. The crystal structure of these acids was found to be dependent upon solvent used for recrystallization; that is, the acids recrystallized from the above solvent becomes more stable energetically, indicating their higher enthalpy change of fusion than that of the solidified acids from fused ones. The solid state was also found to vary depending upon the thermal history, indicating that a few crystal structures of the solid state are quite similar energetically. The melting points (T(m)) of perfluoro-n-alkanoic acids are higher than those of corresponding n-alkanoic acids, and the difference in T(m) increases with increasing carbon number in the acids.
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Affiliation(s)
- Minami Tsuji
- Division of Biointerfacial Science, Graduate School of Pharmaceutical Sciences, Kyushu University 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
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43
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Waterland RL, Dobbs KD. Atmospheric Chemistry of Linear Perfluorinated Aldehydes: Dissociation Kinetics of CnF2n+1CO Radicals. J Phys Chem A 2007; 111:2555-62. [PMID: 17388359 DOI: 10.1021/jp067587+] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Linear perfluorinated aldehydes (PFALs, CnF2n+1CHO) are important intermediate species in the atmospheric oxidation pathway of many polyfluorinated compounds. PFALs can be further oxidized in the gas phase to give perfluorinated carboxylic acids (PFCAs, CnF2n+1C(O)OH, n = 6, 12) which have been detected in animal tissues and at low parts per billion levels in human blood sera. In this paper, we report ab initio quantum chemistry calculations of the decarbonylation kinetics of CnF2n+1CO radicals. Our results show that CnF2n+1CO radicals have a strong tendency to decompose to give CnF2n+1 and CO under atmospheric conditions: the Arrhenius activation energies for decarbonylation of CF3CO, C2F5CO, and C3F7CO obtained using PMP4/6-311++G(2d,p) are 8.8, 6.6, and 5.8 kcal/mol, respectively, each of which is about 5 kcal/mol lower than the barrier for the corresponding nonfluorinated radicals. The lowering of the barrier for decarbonylation of CnF2n+1CO relative to that of CnH2n+1CO is well explained by electron withdrawal by F atoms that serve to weaken the critical C-CO bond. These results have important implications for the atmospheric fate of PFALs and the atmospheric pathways to PFCAs. The main effect of decarbonylation of CnF2n+1CO is to decrease the molar yield of CnF2n+1C(O)OH; if 100% of the CnF2n+1CO decompose, the yield of CnF2n+1C(O)OH must be zero. There is considerable scope for additional experimental and theoretical studies.
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Affiliation(s)
- Robert L Waterland
- DuPont Central Research & Development, Experimental Station, P. O. Box 80320, Wilmington, Delaware 19880-0320, USA.
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44
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Agouridas V, Blazejewski JC, Magnier E, Popkin ME. Synthesis of 11beta-perfluorohexylestradiol. J Org Chem 2006; 70:8907-12. [PMID: 16238326 DOI: 10.1021/jo051424k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] We report the synthesis of 11beta-perfluorohexylestradiol 1e using a perfluoroorganometallic reagent for the introduction of the fluorous part. This compound is useful for biological studies and for imaging the ERalpha estradiol receptor distribution in the whole cell by secondary ion mass spectrometry (SIMS). The key step of this synthesis involves the radical reduction of an 11beta-oxalate derivative. The stereochemical outcome of this reaction was studied for a range of C11 substituents, and we attempted to rationalize the apparent abnormal behavior of the phenyl group.
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45
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Hori H, Yamamoto A, Kutsuna S. Efficient photochemical decomposition of long-chain perfluorocarboxylic acids by means of an aqueous/liquid CO2 biphasic system. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:7692-7. [PMID: 16245846 DOI: 10.1021/es050753r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Photochemical decomposition of persistent and bioaccumulative long-chain (C9-C11) perfluorocarboxylic acids (PFCAs) with persulfate ion (S2O8(2-)) in an aqueous/liquid CO2 biphasic system was examined to develop a technique to neutralize stationary sources of the long-chain PFCAs. The long-chain PFCAs, namely, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUA), which are used as emulsifying agents and as surface treatment agents in industry, are relatively insoluble in water but are soluble in liquid CO2; therefore, introduction of liquid CO2 to the aqueous photoreaction system reduces the interference of colloidal PFCA particles. When the biphasic system was used to decompose these PFCAs, the extent of reaction was 6.4-51 times as high as that achieved in the absence of CO2. In the biphasic system, PFNA, PFDA, and PFUA (33.5-33.6 micromol) in 25.0 mL of water were 100%, 100%, and 77.1% decomposed, respectively, after 12 h of irradiation with a 200-W xenon-mercury lamp; F- ions were produced as a major product, and short-chain PFCAs, which are less bioaccumulative than the original PFCAs, were minor products. All of the initial S2O8(2-) was transformed to SO42-. The system also efficiently decomposed PFCAs at lower concentrations (e.g., 4.28-16.7 micromol of PFDA in 25.0 mL) and was successfully applied to decompose PFNA in floor wax.
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Affiliation(s)
- Hisao Hori
- National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba West, 16-1 Onogawa, Tsukuba 305-8569, Japan.
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46
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Buchanan GW, Munteanu E, Dawson BA, Hodgson D. Concerning the origin of 19F-19F NMR COSY and NOESY connections in the spectra of perfluorooctanoic acid, R(F)-palmitic acid-F13 and diethyl perfluorosuberate. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2005; 43:528-534. [PMID: 15864819 DOI: 10.1002/mrc.1595] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A combination of 19F nuclear Overhauser effects (NOE) and molecular mechanics calculations are presented for delineating the spatial origin of the well-known four-bond 19F-19F COSY connections which are generally observed in the 19F NMR spectra of compounds containing perfluorinated chains. Perfluorooctanoic acid (PFOA), R(F)-palmitic acid-F13 and diethyl perfluorosuberate were used as test cases. Spin-lattice relaxation times (T1) are included and NOESY correlations through three and four bonds occur.
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Affiliation(s)
- Gerald W Buchanan
- Ottawa-Carleton Chemistry Institute, Department of Chemistry, Carleton University, Ottawa, Canada, K1S 5B6.
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