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Garnett J, Halsall C, Winton H, Joerss H, Mulvaney R, Ebinghaus R, Frey M, Jones A, Leeson A, Wynn P. Increasing Accumulation of Perfluorocarboxylate Contaminants Revealed in an Antarctic Firn Core (1958-2017). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11246-11255. [PMID: 35881889 PMCID: PMC9386903 DOI: 10.1021/acs.est.2c02592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/12/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Perfluoroalkyl acids (PFAAs) are synthetic chemicals with a variety of industrial and consumer applications that are now widely distributed in the global environment. Here, we report the measurement of six perfluorocarboxylates (PFCA, C4-C9) in a firn (granular compressed snow) core collected from a non-coastal, high-altitude site in Dronning Maud Land in Eastern Antarctica. Snow accumulation of the extracted core dated from 1958 to 2017, a period coinciding with the advent, use, and geographical shift in the global industrial production of poly/perfluoroalkylated substances, including PFAA. We observed increasing PFCA accumulation in snow over this time period, with chemical fluxes peaking in 2009-2013 for perfluorooctanoate (PFOA, C8) and nonanoate (PFNA, C9) with little evidence of a decline in these chemicals despite supposed recent global curtailments in their production. In contrast, the levels of perfluorobutanoate (PFBA, C4) increased markedly since 2000, with the highest fluxes in the uppermost snow layers. These findings are consistent with those previously made in the Arctic and can be attributed to chlorofluorocarbon replacements (e.g., hydrofluoroethers) as an inadvertent consequence of global regulation.
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Affiliation(s)
- Jack Garnett
- Lancaster
Environment Centre, Lancaster University, Lancaster LA1 4YQ, U.K.
| | - Crispin Halsall
- Lancaster
Environment Centre, Lancaster University, Lancaster LA1 4YQ, U.K.
| | - Holly Winton
- British
Antarctic Survey, Cambridge, High Cross, Madingley Road, Cambridge CB3 0ET, U.K.
- Antarctic
Research Centre, Victoria University of
Wellington, Wellington 6012, New Zealand
| | - Hanna Joerss
- Helmholtz-Zentrum
Hereon, Max-Planck-Straße 1, 21502 Geesthacht, Germany
| | - Robert Mulvaney
- British
Antarctic Survey, Cambridge, High Cross, Madingley Road, Cambridge CB3 0ET, U.K.
| | - Ralf Ebinghaus
- Helmholtz-Zentrum
Hereon, Max-Planck-Straße 1, 21502 Geesthacht, Germany
| | - Markus Frey
- British
Antarctic Survey, Cambridge, High Cross, Madingley Road, Cambridge CB3 0ET, U.K.
| | - Anna Jones
- British
Antarctic Survey, Cambridge, High Cross, Madingley Road, Cambridge CB3 0ET, U.K.
| | - Amber Leeson
- Lancaster
Environment Centre, Lancaster University, Lancaster LA1 4YQ, U.K.
| | - Peter Wynn
- Lancaster
Environment Centre, Lancaster University, Lancaster LA1 4YQ, U.K.
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Theoretical investigations on the OH radical mediated kinetics of cis- and trans-CH3CF=CHF and CH3CH=CF2 over temperature range of 200-400K. J Fluor Chem 2021. [DOI: 10.1016/j.jfluchem.2021.109884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Rivela CB, Gibilisco RG, Tovar CM, Barnes I, Wiesen P, Blanco MB, Teruel MA. FTIR product study of the Cl-initiated oxidation products of CFC replacements: ( E/ Z)-1,2,3,3,3-pentafluoropropene and hexafluoroisobutylene. RSC Adv 2021; 11:12739-12747. [PMID: 35423798 PMCID: PMC8696996 DOI: 10.1039/d1ra00283j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/10/2021] [Indexed: 11/21/2022] Open
Abstract
A product study of the reactions of (E/Z)-1,2,3,3,3-pentafluoropropene ((E/Z)-CF3CF[double bond, length as m-dash]CHF) and hexafluoroisobutylene ((CF3)2C[double bond, length as m-dash]CH2) initiated by Cl atoms were developed at 298 ± 2 K and atmospheric pressure. The experiments were carried out in a 1080 L quartz-glass environmental chamber coupled via in situ FTIR spectroscopy to monitor the reactants and products. The main products observed and their yields were as follows: CF3C(O)F (106 ± 9)% with HC(O)F (100 ± 8)% as a co-product for (E/Z)-CF3CF[double bond, length as m-dash]CHF, and CF3C(O)CF3 (94 ± 5)% with HC(O)Cl (90 ± 7)% as a co-product for (CF3)2C[double bond, length as m-dash]CH2. Atmospheric implications of the end-product degradation are assessed in terms of their impact on ecosystems to help environmental policymakers consider HFOs as acceptable replacements.
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Affiliation(s)
- Cynthia B Rivela
- Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba Ciudad Universitaria 5000 Córdoba Argentina
| | - Rodrigo G Gibilisco
- Physikalische Chemie/FBC, Bergische Universitaet Wuppertal Wuppertal Germany
| | - Carmen M Tovar
- Physikalische Chemie/FBC, Bergische Universitaet Wuppertal Wuppertal Germany
| | - Ian Barnes
- Physikalische Chemie/FBC, Bergische Universitaet Wuppertal Wuppertal Germany
| | - Peter Wiesen
- Physikalische Chemie/FBC, Bergische Universitaet Wuppertal Wuppertal Germany
| | - María B Blanco
- Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba Ciudad Universitaria 5000 Córdoba Argentina
| | - Mariano A Teruel
- Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba Ciudad Universitaria 5000 Córdoba Argentina
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Liu Y, Wang W. Atmospheric oxidation chemistry of hexafluoroisobutylene initiated by OH radical: Kinetics and mechanism. COMPUT THEOR CHEM 2021. [DOI: 10.1016/j.comptc.2020.113137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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5
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Zhou X, Liu Y, Chen Y, Li X, Xiao C, Dong W, Yang X. Kinetic Studies for the Reaction of syn-CH 3CHOO with CF 3CH═CH 2. J Phys Chem A 2020; 124:6125-6132. [PMID: 32614580 DOI: 10.1021/acs.jpca.0c03534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hydrofluoroolefins (HFOs, CxF2x+1CH═CH2) have great potential to replace hydrofluorocarbons (HFCs) as refrigerants. Here the kinetics for the reaction of syn-CH3CHOO with CF3CH═CH2 (HFO-1243zf), the simplest of HFOs, have been studied in a flash photolysis flow reactor at a total pressure of 50 Torr, by using the OH laser-induced fluorescence (LIF) method. The bimolecular reaction rate coefficients were measured at temperatures ranging from 283 to 318 K. A weak positive temperature dependence was observed, with an activation energy of 1.41 ± 0.12 kcal mol-1. At 298 K, the measured rate coefficient was (2.42 ± 0.51) × 10-14 cm3 s-1, in the vicinity of the previously reported upper limit value for the reaction of CH2OO with CF3CH═CH2.
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Affiliation(s)
- Xiaohu Zhou
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.,Zhang Dayu School of Chemistry, Dalian University of Technology, Dalian, 116024, China.,State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Yiqiang Liu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.,Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, 116024, China
| | - Yang Chen
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.,Key Laboratory of Chemical Lasers, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xinyong Li
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China
| | - Chunlei Xiao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Wenrui Dong
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.,Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
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6
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Brown TM, Macdonald RW, Muir DCG, Letcher RJ. The distribution and trends of persistent organic pollutants and mercury in marine mammals from Canada's Eastern Arctic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 618:500-517. [PMID: 29145101 DOI: 10.1016/j.scitotenv.2017.11.052] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/03/2017] [Accepted: 11/04/2017] [Indexed: 05/15/2023]
Abstract
Arctic contaminant research in the marine environment has focused on organohalogen compounds and mercury mainly because they are bioaccumulative, persistent and toxic. This review summarizes and discusses the patterns and trends of persistent organic pollutants (POPs) and mercury in ringed seals (Pusa hispida) and polar bears (Ursus maritimus) in the Eastern Canadian Arctic relative to the rest of the Canadian Arctic. The review provides explanations for these trends and looks at the implications of climate-related changes on contaminants in these marine mammals in a region that has been reviewed little. Presently, the highest levels of total mercury (THg) and the legacy pesticide HCH in ringed seals and polar bears are found in the Western Canadian Arctic relative to other locations. Whereas, highest levels of some legacy contaminants, including ∑PCBs, PCB 153, ∑DDTs, p,p'-DDE, ∑CHLs, ClBz are found in the east (i.e., Ungava Bay and Labrador) and in the Beaufort Sea relative to other locations. The highest levels of recent contaminants, including PBDEs and PFOS are found at lower latitudes. Feeding ecology (e.g., feeding at a higher trophic position) is shaping the elevated levels of THg and some legacy contaminants in the west compared to the east. Spatial and temporal trends for POPs and THg are underpinned by historical loadings of surface ocean reservoirs including the Western Arctic Ocean and the North Atlantic Ocean. Trends set up by the distribution of water masses across the Canadian Arctic Archipelago are then acted upon locally by on-going atmospheric deposition, which is the dominant contributor for more recent contaminants. Warming and continued decline in sea ice are likely to result in further shifts in food web structure, which are likely to increase contaminant burdens in marine mammals. Monitoring of seawater and a range of trophic levels would provide a better basis to inform communities about contaminants in traditionally harvested foods, allow us to understand the causes of contaminant trends in marine ecosystems, and to track environmental response to source controls instituted under international conventions.
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Affiliation(s)
- Tanya M Brown
- Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X9, Canada.
| | - Robie W Macdonald
- Fisheries, Oceans and the Canadian Coast Guard, Institute of Ocean Sciences, Sidney, British Columbia V8L 4B2, Canada; Centre for Earth Observation Science, Department of Environment and Geography, University of Manitoba, Winnipeg R3T 2N2, Canada
| | - Derek C G Muir
- Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario L7R 4A6, Canada
| | - Robert J Letcher
- Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario K1A 0H3, Canada
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7
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Ballesteros B, Jiménez E, Moreno A, Soto A, Antiñolo M, Albaladejo J. Atmospheric fate of hydrofluoroolefins, C xF 2x+1CHCH 2 (x = 1,2,3,4 and 6): Kinetics with Cl atoms and products. CHEMOSPHERE 2017; 167:330-343. [PMID: 27736711 DOI: 10.1016/j.chemosphere.2016.09.156] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/20/2016] [Accepted: 09/30/2016] [Indexed: 06/06/2023]
Abstract
Rate coefficients for the gas-phase reactions of CxF2x+1CHCH2 (x = 1, 2, 3, 4 and 6) with Cl atoms were determined at (298 ± 2) K and (710 ± 5) Torr of air using a relative rate technique. Two experimental setups with simulation chambers were employed with Fourier Transform Infrared (FTIR) spectroscopy and Gas Chromatography coupled to Mass Spectrometry (GC-MS) as detection techniques. The Cl-rate coefficients obtained were (in 10-10 cm3 molecule-1 s-1): (0.85 ± 0.11) for CF3CHCH2, (1.11 ± 0.08) for C2F5CHCH2, (1.12 ± 0.18) for C3F7CHCH2, (0.97 ± 0.09) for C4F9CHCH2, and (0.99 ± 0.08) for C6F13CHCH2. Additionally, the gas-phase products were identified and quantified, when possible, by FTIR spectroscopy or GC-MS. The main reaction product was reported to be CxF2x+1C(O)CH2Cl. The fluorinated species, CxF2x+1CHO and CxF2x+1C(O)CH2Cl, were identified. CF3C(O)CH2Cl and CF3CHO were found to be formed with molar yield of (69 ± 5)% and (9 ± 1)%, respectively. The global lifetime of the investigated CxF2x+1CHCH2 due to their Cl-reaction is more than 100 days so this route does not compete with the removal by OH radicals. This lifetime is long enough for CxF2x+1CHCH2 to be transported to remote areas where they can be degraded. However, at a local scale, in marine regions at dawn the removal of CxF2x+1CHCH2 is expected to occur in ca. 1 day. The atmospheric degradation of these hydrofluoroolefins by Cl atoms is not expected to be a source of bioaccumulative perfluorinated carboxylic acids, CxF2x+1C(O)OH. Additionally, the UV absorption cross sections of CF3C(O)CH2Cl were determined together with the rate coefficient of the OH reaction by an absolute kinetic method at room temperature.
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Affiliation(s)
- Bernabé Ballesteros
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avenida Camilo José Cela 1B, 13071 Ciudad Real, Spain; Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain.
| | - Elena Jiménez
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avenida Camilo José Cela 1B, 13071 Ciudad Real, Spain; Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain
| | - Alberto Moreno
- Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain
| | - Amparo Soto
- Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain
| | - María Antiñolo
- Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain
| | - José Albaladejo
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avenida Camilo José Cela 1B, 13071 Ciudad Real, Spain; Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain
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Jiménez E, González S, Cazaunau M, Chen H, Ballesteros B, Daële V, Albaladejo J, Mellouki A. Atmospheric Degradation Initiated by OH Radicals of the Potential Foam Expansion Agent, CF3(CF2)2CH═CH2 (HFC-1447fz): Kinetics and Formation of Gaseous Products and Secondary Organic Aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:1234-1242. [PMID: 26704369 DOI: 10.1021/acs.est.5b04379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The assessment of the atmospheric impact of the potential foam expansion agent, CF3(CF2)2CH═CH2 (HFC-1447fz), requires the knowledge of its degradation routes, oxidation products, and radiative properties. In this paper, the gas-phase reactivity of HFC-1447fz with OH radicals is presented as a function of temperature, obtaining kOH (T = 263-358 K) = (7.4 ± 0.4) × 10(-13)exp{(161 ± 16)/T} (cm(3)·molecule(-1)·s(-1)) (uncertainties: ±2σ). The formation of gaseous oxidation products and secondary organic aerosols (SOAs) from the OH + HFC-1447fz reaction was investigated in the presence of NOx at 298 K. CF3(CF2)2CHO was observed at low- and high-NOx conditions. Evidence of SOA formation (ultrafine particles in the range 10-100 nm) is reported with yields ranging from 0.12 to 1.79%. In addition, the absolute UV (190-368 nm) and IR (500-4000 cm(-1)) absorption cross-sections of HFC-1447fz were determined at room temperature. No appreciable absorption in the solar actinic region (λ > 290 nm) was observed, leaving the removal by OH radicals as the main atmospheric loss process for HFC-1447fz. The major contribution of the atmospheric loss of HFC-1447fz is due to OH reaction (84%), followed by ozone (10%) and chlorine atoms (6%). Correction of the instantaneous radiative efficiency (0.36 W m(-2)·ppbv(-1)) with the relatively short lifetime of HFC-1447fz (ca. 8 days) implies that its global warming potential at a time horizon of 100 year is negligible (0.19) compared to that of HCFC-141b (782) and to that of modern foam-expansion blowing agents (148, 882, and 804 for HFC-152a, HFC-245fa and HFC-365mfc, respectively).
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Affiliation(s)
- Elena Jiménez
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha (UCLM) , Avenue de Camilo José Cela, s/n, 13071 Ciudad Real, Spain
- Research Institute on Combustion and Atmospheric Pollution (UCLM) , Camino de Moledores 13071 Ciudad Real, Spain
| | - Sergio González
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha (UCLM) , Avenue de Camilo José Cela, s/n, 13071 Ciudad Real, Spain
| | - Mathieu Cazaunau
- Centre National de la Recherche Scientifique, Institut de Combustion Aérothermique Réactivité et Environnement ICARE/OSUC, CNRS 1C , Avenue de la Recherche Scientifique, 45071 Orléans cedex 02, France
| | - Hui Chen
- Centre National de la Recherche Scientifique, Institut de Combustion Aérothermique Réactivité et Environnement ICARE/OSUC, CNRS 1C , Avenue de la Recherche Scientifique, 45071 Orléans cedex 02, France
| | - Bernabé Ballesteros
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha (UCLM) , Avenue de Camilo José Cela, s/n, 13071 Ciudad Real, Spain
- Research Institute on Combustion and Atmospheric Pollution (UCLM) , Camino de Moledores 13071 Ciudad Real, Spain
| | - Véronique Daële
- Centre National de la Recherche Scientifique, Institut de Combustion Aérothermique Réactivité et Environnement ICARE/OSUC, CNRS 1C , Avenue de la Recherche Scientifique, 45071 Orléans cedex 02, France
| | - José Albaladejo
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha (UCLM) , Avenue de Camilo José Cela, s/n, 13071 Ciudad Real, Spain
- Research Institute on Combustion and Atmospheric Pollution (UCLM) , Camino de Moledores 13071 Ciudad Real, Spain
| | - Abdelwahid Mellouki
- Centre National de la Recherche Scientifique, Institut de Combustion Aérothermique Réactivité et Environnement ICARE/OSUC, CNRS 1C , Avenue de la Recherche Scientifique, 45071 Orléans cedex 02, France
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González S, Jiménez E, Ballesteros B, Martínez E, Albaladejo J. Hydroxyl radical reaction rate coefficients as a function of temperature and IR absorption cross sections for CF3CH=CH2 (HFO-1243zf), potential replacement of CF3CH2F (HFC-134a). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:4793-4805. [PMID: 25138554 DOI: 10.1007/s11356-014-3426-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 08/07/2014] [Indexed: 06/03/2023]
Abstract
CF3CH=CH2 (hydrofluoroolefin, HFO-1243zf) is a potential replacement of high global-warming potential (GWP) hydrofluorocarbon (HFC-134a, CF3CFH2). Both the atmospheric lifetime and the radiative efficiency of HFO-1243zf are parameters needed for estimating the GWP of this species. Therefore, the aim of this work is (i) to estimate the atmospheric lifetime of HFO-1243zf from the reported OH rate coefficients, k OH, determined under tropospheric conditions and (ii) to calculate its radiative efficiency from the reported IR absorption cross sections. The OH rate coefficient at 298 K also allows the estimation of the photochemical ozone creation potential (ε(POCP)). The pulsed laser photolysis coupled to a laser-induced fluorescence technique was used to determine k OH for the reaction of OH radicals with HFO-1243zf as a function of pressure (50-650 Torr of He) and temperature (263-358 K). Gas-phase IR spectra of HFO-1243zf were recorded at room temperature using a Fourier transform IR spectrometer between 500 and 4,000 cm(-1). At all temperatures, k OH did not depend on bath gas concentration (i.e., on the total pressure between 50 and 650 Torr of He). A slight but noticeable T dependence of k OH was observed in the temperature range investigated. The observed behavior is well described by the following Arrhenius expression: k OH(T) = (7.65 ± 0.26) × 10(-13) exp [(165 ± 10) / T] cm(3) molecule(-1) s(-1). Negligible IR absorption of HFO-1243zf was observed at wavenumbers greater than 1,700 cm(-1). Therefore, IR absorption cross sections, [Formula: see text], were determined in the 500-1,700 cm(-1) range. Integrated [Formula: see text] were determined between 650 and 1,800 cm(-1) for comparison purposes. The main diurnal removal pathway for HFO-1243zf is the reaction with OH radicals, which accounts for 64% of the overall loss by homogeneous reactions at 298 K. Globally, the lifetime due to OH reaction (τ OH) was estimated to be 8.7 days under the assumption of a well-mixed atmosphere. Assuming other removal pathways, the atmospheric lifetime (τ) was estimated to be ∼6 days. Considering the estimated τ OH and the measured IR absorption cross sections of HFO-1243zf in the atmospheric window (720-1,250 cm(-1)), its lifetime corrected radiative efficiency was calculated to be 0.019 W m(-2) ppbv(-1). GWP100 years for the HFO investigated, 0.29, is negligible compared to that of HFC-134a, the HFC to be potentially replaced (GWP100 years = 1,300, Hodnebrog et al. (Rev Geophys 51:300-378, 2013)). ε POCP for HFO-1243zf was estimated to be around 1 order of magnitude lower than that for ethylene. In conclusion, HFO-1243zf is fast degraded in the atmosphere, and it does not appreciably contribute to global warming and local/regional air pollution. Therefore, HFO-1243zf can be a suitable replacement for HFC-134a in air conditioning units.
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Affiliation(s)
- Sergio González
- Department of Physical Chemistry, Faculty of Chemical Sciences and Technologies, University of Castilla-La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain
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10
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Papadimitriou VC, Spitieri CS, Papagiannakopoulos P, Cazaunau M, Lendar M, Daële V, Mellouki A. Atmospheric chemistry of (CF3)2CCH2: OH radicals, Cl atoms and O3 rate coefficients, oxidation end-products and IR spectra. Phys Chem Chem Phys 2015; 17:25607-20. [DOI: 10.1039/c5cp03840e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
OH, Cl and O3 kinetics and IR spectra of (CF3)2CCH2 utilized to estimate tropospheric lifetimes, radiative efficiencies, global warming potentials, estimated photochemical ozone creation potentials and tropospheric oxidation end-products.
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Affiliation(s)
| | - Christina S. Spitieri
- Laboratory of Photochemistry and Kinetics
- Department of Chemistry
- University of Crete
- Heraklion
- Greece
| | - Panos Papagiannakopoulos
- Laboratory of Photochemistry and Kinetics
- Department of Chemistry
- University of Crete
- Heraklion
- Greece
| | - Mathieu Cazaunau
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement
- CNRS/OSUC
- Orléans
| | - Maria Lendar
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement
- CNRS/OSUC
- Orléans
| | - Véronique Daële
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement
- CNRS/OSUC
- Orléans
| | - Abdelwahid Mellouki
- Institut de Combustion
- Aérothermique
- Réactivité et Environnement
- CNRS/OSUC
- Orléans
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11
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Mechanism, kinetics and atmospheric fate of CF3CHCH2, CF3CFCH2, and CF3CFCF2 by its reaction with OH-radicals: CVT/SCT/ISPE and hybrid meta-DFT methods. J Mol Graph Model 2014; 48:60-9. [DOI: 10.1016/j.jmgm.2013.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 11/30/2013] [Accepted: 12/02/2013] [Indexed: 11/17/2022]
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Zhang W, Du B. Quantum chemical study of the mechanism for OH-initiated atmospheric oxidation reaction of (Z)-CF3CFCHF. COMPUT THEOR CHEM 2012. [DOI: 10.1016/j.comptc.2012.03.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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13
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Sulbaek Andersen MP, Waterland RL, Sander SP, Nielsen OJ, Wallington TJ. Atmospheric chemistry of CxF2x+1CHCH2 (x=1, 2, 4, 6 and 8): Radiative efficiencies and global warming potentials. J Photochem Photobiol A Chem 2012. [DOI: 10.1016/j.jphotochem.2012.02.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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14
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Andersen MPS, Nielsen OJ, Hurley MD, Wallington TJ. Atmospheric chemistry of t-CF3CHCHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals. Phys Chem Chem Phys 2012; 14:1735-48. [DOI: 10.1039/c1cp22925g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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15
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Rotander A, Kärrman A, van Bavel B, Polder A, Rigét F, Auðunsson GA, Víkingsson G, Gabrielsen GW, Bloch D, Dam M. Increasing levels of long-chain perfluorocarboxylic acids (PFCAs) in Arctic and North Atlantic marine mammals, 1984-2009. CHEMOSPHERE 2012; 86:278-285. [PMID: 22051347 DOI: 10.1016/j.chemosphere.2011.09.054] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 09/22/2011] [Accepted: 09/29/2011] [Indexed: 05/31/2023]
Abstract
Temporal variations in concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs), including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) structural isomers, were examined in livers of pilot whale (Globicephala melas), ringed seal (Phoca hisida), minke whale (Balaenoptera acutorostrata), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), Atlantic white-sided dolphin (Lagenorhynchus acutus) and in muscle tissue of fin whales (Balaenoptera physalus). The sampling spanned over 20 years (1984-2009) and covered a large geographical area of the North Atlantic and West Greenland. Liver and muscle samples were homogenized, extracted with acetonitrile, cleaned up using hexane and solid phase extraction (SPE), and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). In general, the levels of the long-chained PFCAs (C9-C12) increased whereas the levels of PFOS remained steady over the studied period. The PFOS isomer pattern in pilot whale liver was relatively constant over the sampling years. However, in ringed seals there seemed to be a decrease in linear PFOS (L-PFOS) with time, going from 91% in 1984 to 83% in 2006.
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Affiliation(s)
- Anna Rotander
- Man-Technology-Environment Research Centre, Örebro University, SE-701 82 Örebro, Sweden.
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16
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Buck RC, Franklin J, Berger U, Conder JM, Cousins IT, de Voogt P, Jensen AA, Kannan K, Mabury SA, van Leeuwen SPJ. Perfluoroalkyl and polyfluoroalkyl substances in the environment: terminology, classification, and origins. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2011; 7:513-41. [PMID: 21793199 PMCID: PMC3214619 DOI: 10.1002/ieam.258] [Citation(s) in RCA: 2155] [Impact Index Per Article: 165.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 05/26/2011] [Accepted: 07/05/2011] [Indexed: 05/18/2023]
Abstract
The primary aim of this article is to provide an overview of perfluoroalkyl and polyfluoroalkyl substances (PFASs) detected in the environment, wildlife, and humans, and recommend clear, specific, and descriptive terminology, names, and acronyms for PFASs. The overarching objective is to unify and harmonize communication on PFASs by offering terminology for use by the global scientific, regulatory, and industrial communities. A particular emphasis is placed on long-chain perfluoroalkyl acids, substances related to the long-chain perfluoroalkyl acids, and substances intended as alternatives to the use of the long-chain perfluoroalkyl acids or their precursors. First, we define PFASs, classify them into various families, and recommend a pragmatic set of common names and acronyms for both the families and their individual members. Terminology related to fluorinated polymers is an important aspect of our classification. Second, we provide a brief description of the 2 main production processes, electrochemical fluorination and telomerization, used for introducing perfluoroalkyl moieties into organic compounds, and we specify the types of byproducts (isomers and homologues) likely to arise in these processes. Third, we show how the principal families of PFASs are interrelated as industrial, environmental, or metabolic precursors or transformation products of one another. We pay particular attention to those PFASs that have the potential to be converted, by abiotic or biotic environmental processes or by human metabolism, into long-chain perfluoroalkyl carboxylic or sulfonic acids, which are currently the focus of regulatory action. The Supplemental Data lists 42 families and subfamilies of PFASs and 268 selected individual compounds, providing recommended names and acronyms, and structural formulas, as well as Chemical Abstracts Service registry numbers.
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Affiliation(s)
- Robert C Buck
- E.I. du Pont de Nemours & Co., Inc., DuPont Chemicals and FluoroproductsWilmington, Delaware, USA
| | - James Franklin
- CLF-Chem Consulting3 Clos du Châtaignier, BE-1390 Grez-Doiceau, Belgium
| | - Urs Berger
- Department of Applied Environmental Science (ITM), Stockholm UniversityStockholm, Sweden
| | | | - Ian T Cousins
- Department of Applied Environmental Science (ITM), Stockholm UniversityStockholm, Sweden
| | - Pim de Voogt
- Institute for Biodiversity and Ecosystem Dynamics, University of AmsterdamAmsterdam, The Netherlands
| | - Allan Astrup Jensen
- Nordic Institute for Product Sustainability, Environmental Chemistry and Toxicology (NIPSECT)Frederiksberg, Denmark
| | - Kurunthachalam Kannan
- Wadsworth Center, New York State Department of Health, and Department of Environmental Health Sciences, School of Public Health, State University of New York at AlbanyAlbany, New York, USA
| | - Scott A Mabury
- Department of Chemistry, University of TorontoToronto, Ontario, Canada
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Butt CM, Muir DCG, Mabury SA. Biotransformation of the 8:2 fluorotelomer acrylate in rainbow trout. 1. In vivo dietary exposure. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2010; 29:2726-2735. [PMID: 20836063 DOI: 10.1002/etc.349] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 04/21/2010] [Accepted: 05/13/2010] [Indexed: 05/29/2023]
Abstract
The bioaccumulation and biotransformation of the 8:2 fluorotelomer acrylate (C(8) F(17) CH(2) CH(2) OC(O)CH = CH(2) , 8:2 FTAc) was investigated in rainbow trout via dietary exposure. The 8:2 FTAc is a monomer used in the manufacture of fluorinated polymers and has been widely detected in the atmosphere. The parent 8:2 FTAc and suspected intermediate and terminal metabolites were monitored in liver, blood, kidney, bile, and feces during the 5-d uptake and 8-d elimination phases using gas chromatography-mass spectrometry (GC-MS)- and liquid chromatography-tandem mass spectrometry (LC-MS/MS)- based methods. Very low levels of the 8:2 FTAc were detected in the internal tissues and feces, suggesting that the 8:2 FTAc was rapidly biotransformed in the gut or liver. Similarly, low concentrations of the 8:2 fluorotelomer alcohol (FTOH) were accumulated in the fish tissues. The 8:2 saturated fluorotelomer carboxylate (FTCA) was formed in the highest concentration, reaching steady-state tissue concentrations of approximately 1,000 to 1,400 ng/g wet weight. The 8:2 FTUCA and 7:3 FTCA were also accumulated in high levels, at levels approximately 10-fold lower than the 8:2 FTCA. Both the 7:3 FTCA and perfluorooctanoate (PFOA) showed increasing levels throughout the uptake phase and into the initial stages of the elimination phase, indicating continued formation through precursors still present in the body. Perfluorononanoate (PFNA) was formed in low nanogram per gram wet weight levels. The intermediate and terminal metabolites were also detected in the bile and feces, indicating an important elimination pathway for these compounds. In addition, the 8:2 FTOH glucuronide conjugate was measured in relatively high concentrations in the bile and feces. The results of the current study demonstrated a scenario in which a biologically labile compound is biotransformed to terminal metabolites that are much more biologically persistent.
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Affiliation(s)
- Craig M Butt
- Department of Chemistry, University of Toronto, 80 St George Street, Toronto, Ontario M5S 3H6, Canada
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18
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Butt CM, Berger U, Bossi R, Tomy GT. Levels and trends of poly- and perfluorinated compounds in the arctic environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2010; 408:2936-65. [PMID: 20493516 DOI: 10.1016/j.scitotenv.2010.03.015] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 03/11/2010] [Accepted: 03/11/2010] [Indexed: 04/14/2023]
Abstract
Poly- and perfluorinated organic compounds (PFCs) are ubiquitous in the Arctic environment. Several modeling studies have been conducted in attempt to resolve the dominant transport pathway of PFCs to the arctic-atmospheric transport of precursors versus direct transport via ocean currents. These studies are generally limited by their focus on perfluorooctanoate (PFOA) fluxes to arctic seawater and thus far have only used fluorotelomer alcohols (FTOHs) and sulfonamide alcohols as inputs for volatile precursors. There have been many monitoring studies from the North American and European Arctic, however, almost nothing is known about PFC levels from the Russian Arctic. In general, there are very few measurements of PFCs from the abiotic environment. Atmospheric measurements show the widespread occurrence of PFC precursors, FTOHs and perfluorinated sulfonamide alcohols. Further, PFCAs and PFSAs have been detected on atmospheric particles. The detection of PFCAs and PFSAs in snow deposition is consistent with the volatile precursor transport hypothesis. There are very limited measurements of PFCs in seawater. PFOA is generally detected in the greatest concentrations. Additional seawater measurements are needed to validate existing model predications. The bulk of the monitoring efforts in biological samples have focused on the perfluorinated carboxylates (PFCAs) and sulfonates (PFSAs), although there are very few measurements of PFC precursors. The marine food web has been well studied, particularly the top predators. In contrast, freshwater and terrestrial ecosystems have been poorly studied. Studies show that in wildlife perfluorooctane sulfonate (PFOS) is generally measured in the highest concentration, followed by either perfluorononanoate (PFNA) or perfluoroundecanoate (PFUnA). However, some whale species show relatively high levels of perfluorooctane sulfonamide (PFOSA) and seabirds are typically characterized by high proportions of the C(11)-C(15) PFCAs. PFOA is generally infrequently detected and is present in low concentrations in arctic biota. Food web studies show high bioaccumulation in the upper trophic-level animals, although the mechanism of PFC biomagnification is not understood. Spatial trend studies show some differences between populations, although there are inconsistencies between PFC trends. The majority of temporal trend studies are from the Northern American Arctic and Greenland. Studies show generally increasing levels of PFCs from the 1970s, although some studies from the Canadian Arctic show recent declines in PFOS levels. In contrast, ringed seals and polar bears from Greenland continue to show increasing PFOS concentrations. The inconsistent temporal trends between regions may be representative of differences in emissions from source regions.
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Affiliation(s)
- Craig M Butt
- Department of Chemistry, University of Toronto, Toronto, Ontario, Canada.
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19
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Butt CM, Muir DCG, Mabury SA. Elucidating the pathways of poly- and perfluorinated acid formation in rainbow trout. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:4973-4980. [PMID: 20518507 DOI: 10.1021/es100702a] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Several studies have shown that fluorotelomer-based compounds can be metabolized to poly- and perfluorinated carboxylates, such as perfluorooctanoate (PFOA). Research has predominately focused on the 8:2 fluorotelomer alcohol (8:2 FTOH), however, the biotransformation pathway is not well understood. Specifically, there is uncertainty regarding the biological fate of the 8:2 fluorotelomer unsaturated carboxylate (FTUCA) and 7:3 fluorotelomer saturated carboxylate (FTCA). The objective of this study was to further elucidate the pathway for 8:2 FTOH biotransformation through dosing rainbow trout with three 8:2 FTOH metabolism intermediates: the 7:3 FTCA (CF(3)(CF(2))(6)CH(2)CH(2)COO(-)), 8:2 FTCA (CF(3)(CF(2))(7)CH(2)COO(-)), and 8:2 FTUCA (CF(3)(CF(2))(6)CF horizontal lineCHCOO(-)). This study represents the first investigation of these three labile intermediate metabolites in an in vivo system. The parent compounds were dosed via the diet and the parent compounds and intermediates were monitored in the blood and liver during the 7-day uptake phase and 10-day elimination phase. Exposure to the 7:3 FTCA did not result in the formation and accumulation of PFOA, but resulted in low levels of the 7:3 FTUCA and perfluoroheptanoate, a novel finding. PFOA was formed in the 8:2 FTCA and 8:2 FTUCA dosing. In addition, the 7:3 FTCA was formed during exposure to both the 8:2 FTCA and 8:2 FTUCA. Elimination half-lives were 5.1 d (95% confidence interval: 3.1-14 d) for 7:3 FTCA, 1.2 d (1.1-1.3 d) for 8:2 FTCA, and 0.39 d (0.31-0.53 d) for 8:2 FTUCA. The observed differences in the elimination half-life may be the result of differences in either the depuration or metabolism rate. Based on the findings of this study, and reported analogous literature pathways, we proposed a "beta-like-oxidation" pathway for PFOA formation proceeding from the 8:2 FTUCA > 7:3 beta-keto acid > 7:2 ketone > PFOA. Alternatively PFOA could be formed directly through the beta-oxidation of the 7:3 beta-keto acid.
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Affiliation(s)
- Craig M Butt
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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20
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Young CJ, Mabury SA. Atmospheric perfluorinated acid precursors: chemistry, occurrence, and impacts. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2010; 208:1-109. [PMID: 20811862 DOI: 10.1007/978-1-4419-6880-7_1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Perfluorocarboxylic acids (PFCAs) can be found from the hydrolysis of perfluoroacyl fluorides and chlorides, which can be produced in three separate ways in the atmosphere. Alternatively, PFCAs can be formed directly in the gas phase through reaction of perfluoroacyl peroxy radicals or perfluorinated aldehyde hydrates. All five mechanisms have been elucidated using smog chamber techniques. Yields of the PFCAs from this process vary from less than 10% to greater than 100%, depending on the mechanism. The formation of perfluorosulfonic acids in the atmosphere can also occur, though the mechanism has not been entirely elucidated. A large number of compounds have been confirmed as perfluorinated acid precursors, including CFC-replacement compounds, anesthetics, fluorotelomer compounds, and perfluorosulfonamides. Levels of some of these compounds have been measured in the atmosphere, but concentration for the majority have yet to be detected. It is clear that atmospheric oxidation of volatile precursors contributes to the overall burden of PFAs, though the extent to which this occurs is compound and environment dependent and is difficult to assess accurately.
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Affiliation(s)
- Cora J Young
- Department of Chemistry, University of Toronto, Toronto, ON, M5S 3H6, Canada.
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21
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Takizawa K, Tokuhashi K, Kondo S. Flammability assessment of CH2CFCF3: comparison with fluoroalkenes and fluoroalkanes. JOURNAL OF HAZARDOUS MATERIALS 2009; 172:1329-1338. [PMID: 19716229 DOI: 10.1016/j.jhazmat.2009.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 07/27/2009] [Accepted: 08/02/2009] [Indexed: 05/28/2023]
Abstract
The burning velocity, flammability limits, and heat of combustion of CH(2)CF=CF(3) (1234yf) have been studied to elucidate the fundamental flammability properties of this new alternative refrigerant with low global-warming potential. The burning velocity of 1234yf was measured independently by schlieren photography and the spherical vessel method. In the spherical vessel method, the burning velocities of 1234yf and its analogues CH(2)=CFCHF(2) (1243yf) and CH(2)=CHCF(3) (1243zf) as well as those of typical fluoroalkanes CH(2)F(2) (HFC-32) and CH(3)=CHF(2) (HFC-152a) were measured in mixtures of air at various O(2)/(N(2)+O(2)) ratios. The maximum burning velocity of 1234yf was found to be 1.2+/-0.3 cm s(-1), which was approximately one-fifth that of HFC-32 (6.7 cm s(-1)) and one order of magnitude less than those of 1243yf (19.8 cm s(-1)) and 1243zf (14.1 cm s(-1)). The flame propagation of 1234yf was highly sensitive to flame temperature compared to that of the other compounds. The measured flammability limits and calculated heat of combustion of 1234yf were also determined.
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Affiliation(s)
- Kenji Takizawa
- National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan.
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22
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23
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Butt CM, Young CJ, Mabury SA, Hurley MD, Wallington TJ. Atmospheric chemistry of 4:2 fluorotelomer acrylate [C4F9CH2CH2OC(O)CH=CH2]: kinetics, mechanisms, and products of chlorine-atom- and OH-radical-initiated oxidation. J Phys Chem A 2009; 113:3155-61. [PMID: 19275140 DOI: 10.1021/jp810358k] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Relative rate techniques were used to measure the rate constants k[Cl + C(4)F(9)CH(2)CH(2)OC(O)CH=CH(2)] = (2.21 +/- 0.16) x 10(-10) and k[OH + C(4)F(9)CH(2)CH(2)OC(O)CH=CH(2)] = (1.13 +/- 0.12) x 10(-11) cm(3) molecule(-1) s(-1) in 700 Torr of N(2) or air diluent at 296 K. The atmospheric lifetime of C(4)F(9)CH(2)CH(2)OC(O)CHCH(2) (4:2 FTAc) is determined by its reaction with OH radicals and is approximately 1 day. The chlorine-atom-initiated oxidation of 4:2 FTAc in 700 Torr of air at 296 K gives C(4)F(9)CH(2)C(O)H in molar yields of 18% and 10% in the absence and presence of NO, respectively. The OH-radical-initiated oxidation of 4:2 FTAc in 700 Torr of air in the presence of NO gives HCHO in a molar yield of (102 +/- 7)%, with C(4)F(9)CH(2)CH(2)OC(O)C(O)H (4:2 fluorotelomer glyoxylate) as the expected coproduct. The atmospheric fate of the 4:2 fluorotelomer glyoxylate will be photolysis and reaction with OH radicals, which will lead to the formation of C(4)F(9)CH(2)C(O)H and ultimately perfluorinated carboxylic acids. The atmospheric oxidation of fluorotelomer acrylates is a potential source of perfluorinated carboxylic acids in remote locations.
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Affiliation(s)
- Craig M Butt
- Department of Chemistry, 80 St. George Street, University of Toronto, Toronto, Ontario, Canada M5S 3H6
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Young CJ, Hurley MD, Wallington TJ, Mabury SA. Atmospheric chemistry of 4:2 fluorotelomer iodide (n-C4F9CH2CH2I): kinetics and products of photolysis and reaction with OH radicals and Cl atoms. J Phys Chem A 2009; 112:13542-8. [PMID: 19053571 DOI: 10.1021/jp807322x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Relative rate techniques were used to study the title reactions and determine rate constants of k(Cl + C(4)F(9)CH(2)CH(2)I) = (1.25 +/- 0.15) x 10(-12) and k(OH + C(4)F(9)CH(2)CH(2)I) = (1.2 +/- 0.6) x 10(-12) cm(3) molecule(-1) s(-1) in 700 Torr total pressure at 295 K. The fluorotelomer aldehyde (C(4)F(9)CH(2)CHO), perfluorinated aldehyde (C(4)F(9)CHO), fluorotelomer acid (C(4)F(9)CH(2)C(O)OH), fluorotelomer peracid (C(4)F(9)CH(2)C(O)OOH), and several perfluorocarboxylic acids were detected by in situ FTIR spectroscopy and offline analysis as products of the chlorine atom initiated oxidation of C(4)F(9)CH(2)CH(2)I in air. The UV-visible spectra of C(4)F(9)CH(2)CH(2)I and C(2)H(5)Cl were recorded over the range of 200-400 nm. Photolysis of C(4)F(9)CH(2)CH(2)I gives C(4)F(9)CH(2)CHO as the major observed product. By assumption of a photolysis quantum yield of unity, it was calculated that the atmospheric lifetime of C(4)F(9)CH(2)CH(2)I is determined by photolysis and is a few days. A mechanism for the atmospheric oxidation of fluorotelomer iodides, (C(x)F(2x+1)CH(2)CH(2)I, where x = 2, 4, 6,...) is proposed. Atmospheric oxidation of fluorotelomer iodides is a potential source of perfluorocarboxylic acids.
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Affiliation(s)
- Cora J Young
- Department of Chemistry, University of Toronto, 80 St George Street, Toronto, Ontario, Canada M5S 3H6
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Russell MH, Berti WR, Szostek B, Buck RC. Investigation of the biodegradation potential of a fluoroacrylate polymer product in aerobic soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:800-7. [PMID: 18323105 DOI: 10.1021/es0710499] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Biodegradation of fluorinated polymers is of interest to assess them as a potential source of perfluorocarboxylates (PFCAs) in the environment. A fluoroacrylate polymer product test substance was studied in four aerobic soils over two years to assess whether the fluorotelomer alcohol (FTOH) side chains covalently bonded to the polymer backbone may be transformed to form PFCAs. The test substance itself was not directly measured; instead, nine analytes were determined to evaluate biodegradation. Terminal biotransformation products measured included perfluorooctanoate (PFO), perfluorononanoate (PFN), perfluorodecanoate (PFD), perfluoroundecanoate (PFU), and pentadecafluorodecanoate (7-3 acid). The molar concentration of 8-2 fluorotelomer alcohol (8-2 FTOH) in the test substance, fluoroacrylate polymer and residual unreacted raw materials and impurities ("residuals") were compared with the molar concentrations of the terminal biotransformation products for mass balance and kinetic assessments. Over the two year time frame of the experimental study, the fluoroacrylate polymer showed a slight extent of potential biodegradation under the experimental conditions of the study. A biodegradation half-life of 1200-1700 years was calculated for the fluoroacrylate polymer based on the rate of formation of PFO in aerobic soils. When the degradation rates of the fluoroacrylate polymer and residuals were applied to estimated total historic fluoroacrylate polymer production, use and disposal, the biodegradation of fluoroacrylate polymer and residuals is calculated to contribute less than 5 tonnes of PFO per year globally to PFCAs present in the environment.
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Affiliation(s)
- Mark H Russell
- E. I. duPont de Nemours and Co., Inc., Wilmington, Delaware, USA.
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26
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Yarwood G, Kemball-Cook S, Keinath M, Waterland RL, Korzeniowski SH, Buck RC, Russell MH, Washburn ST. High-resolution atmospheric modeling of fluorotelomer alcohols and perfluorocarboxylic acids in the North American troposphere. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:5756-62. [PMID: 17874783 DOI: 10.1021/es0708971] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
A high spatial and temporal resolution atmospheric model is used to evaluate the potential contribution of fluorotelomer alcohol (FTOH) and perfluorocarboxylate (PFCA) emissions associated with the manufacture, use, and disposal of DuPont fluorotelomer-based products in North America to air concentrations of FTOH, perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) in North America and the Canadian Arctic. A bottom-up emission inventory for PFCAs and FTOHs was developed from sales and product composition data. A detailed FTOH atmospheric degradation mechanism was developed to simulate FTOH degradation to PFCAs and model atmospheric transport of PFCAs and FTOHs. Modeled PFCA yields from FTOH degradation agree with experimental smog-chamber results supporting the degradation mechanism used. Estimated PFCA and FTOH air concentrations and PFCA deposition fluxes are compared to monitoring data and previous global modeling. Predicted FTOH air concentrations are generally in agreement with available monitoring data. Overall emissions from the global fluorotelomer industry are estimated to contribute approximately 1-2% of the PFCAs in North American rainfall, consistent with previous global emissions estimates. Emission calculations and modeling results indicate that atmospheric inputs of PFCAs in North America from fluorotelomer-based products will decline by an order of magnitude in the near future as a result of current industry commitments to reduce manufacturing emissions and lower the residual fluorotelomer alcohol raw material and trace PFCA product content.
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Affiliation(s)
- Greg Yarwood
- ENVIRON International Corporation, Golden Gate Plaza, 101 Rowland Way, Novato, California 94945, USA
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27
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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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