1
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Lily M, Lv X, Chandra AK, Tsona Tchinda N, Du L. New insights into the mechanism and kinetics of the addition reaction of unsaturated Criegee intermediates to CF 3COOH and tropospheric implications. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024; 26:751-764. [PMID: 38465670 DOI: 10.1039/d3em00554b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
In this work, we have investigated the mechanism, thermochemistry and kinetics of the reaction of syn-cis-CH2RzCRyCO+O- (where Rz, Ry = H, CH3-) unsaturated Criegee intermediates (CIs) with CF3COOH using quantum chemical methods. The rate coefficients for the barrierless reactions were calculated using variable reaction coordinate variational transition state theory (VRC-VTST). For the syn-cis-CH2RzCRyCO+O- conformation in which conjugated CC and CO double bonds are aligned with each other, we propose a new pathway for the unidirectional addition of an OC-OH molecule (CF3COOH) to the CC double bond of syn-cis-CH2RzCRyCO+O-. The rate coefficient for the 1,4-CC addition reaction at 298 K is ∼10-10 to 10-11 cm3 s-1, resulting in the formation of CF3C(O)OCH2CRzRyCOOH trifluoroacetate alkyl allyl hydroperoxide (TFAAAH) as a new transitory adduct. It can act as a precursor for the formation of secondary organic aerosols (SOAs). This novel TFAAAH hydroperoxide was identified through a detailed quantum chemical study of the 1,4-addition mechanism and will provide new insights into the significance of the 1,4-addition reaction of unsaturated Cls with trace tropospheric gases on -CRzCH2 vinyl carbon atoms.
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Affiliation(s)
- Makroni Lily
- Environment Research Institute, Shandong University, Qingdao, 266237, China.
| | - Xiaofan Lv
- Environment Research Institute, Shandong University, Qingdao, 266237, China.
| | - Asit K Chandra
- Department of Chemistry, North-Eastern Hill University, Shillong 793 022, India.
| | | | - Lin Du
- Environment Research Institute, Shandong University, Qingdao, 266237, China.
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2
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Wang Y, Liu L, Qiao X, Sun M, Guo J, Zhao B, Zhang J. Atmospheric fate and impacts of HFO-1234yf from mobile air conditioners in East Asia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170137. [PMID: 38242457 DOI: 10.1016/j.scitotenv.2024.170137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/20/2023] [Accepted: 01/11/2024] [Indexed: 01/21/2024]
Abstract
HFO-1234yf (2,3,3,3-tetrafluoropropene) is being used as refrigerant to replace HFC-134a (1,1,1,2-tetrafluoroethane), a potent greenhouse gas, in mobile air conditioners. However, the environmental impacts of HFO-1234yf, which is quickly and almost completely transformed to the persistent and phytotoxic trifluoroacetic acid (TFA), is of great concern. Here, we used the nested-grid chemical transport model, GEOS-Chem, to assess the fate and environmental impacts of HFO-1234yf emissions from mobile air conditioners in East Asia. With total emissions of 30.3 Gg yr-1, the annual mean concentrations of HFO-1234yf in China, Japan, and South Korea were 4.00, 3.23, and 5.54 pptv (parts per trillion volume), respectively, and the annual deposition fluxes (dry plus wet) of TFA in these regions were 0.35, 0.48, and 0.53 kg km-2 yr-1, dominated by wet deposition. About 14 %, 13 % and 11 % of HFO-1234yf emissions were deposited as TFA in China, Japan and South Korea, respectively, i.e. a large portion of TFA was deposited in areas outside of the emission boundary regions. The TFA characteristics in Japan and South Korea was significantly influenced by emission from China, which contributions ranged from 43 % to 94 % for the TFA concentrations and 44 % to 98 % for the TFA depositions across the four seasons. This suggests that the influence of neighboring emission sources cannot be ignored when assessing the impact of HFO-1234yf emissions in individual countries.
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Affiliation(s)
- Yifei Wang
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Lu Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Xueqi Qiao
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Mei Sun
- Beijing Ecological Environment Assessment and Complaints Center, Beijing 100161, China
| | - Junyu Guo
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Bu Zhao
- School for Environment and Sustainability and Michigan Institute for Computational Discovery & Engineering, University of Michigan, Ann Arbor, MI 48109, United States
| | - Jianbo Zhang
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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3
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Cahill TM. Assessment of Potential Accumulation of Trifluoroacetate in Terminal Lakes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2966-2972. [PMID: 38306688 PMCID: PMC10868581 DOI: 10.1021/acs.est.3c08822] [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: 10/23/2023] [Revised: 01/16/2024] [Accepted: 01/18/2024] [Indexed: 02/04/2024]
Abstract
Trifluoroacetate (TFA) is the anionic form of the shortest perfluorocarboxylic acid (PFCA) and is ubiquitous in the environment at concentrations that are typically much higher than those of other PFCAs. As a stable and nonvolatile anion, it is expected to accumulate in terminal lakes in endorheic basins. This research sampled eight terminal lakes in the Western United States to determine the degree to which TFA is concentrating in these lakes and compare the data to samples collected from three of these lakes 25 years ago. The first observation was that three of the six terminal lakes sampled had higher TFA concentrations than their input streams, while the last two lakes lacked surface water inputs at the sampling time. The TFA concentrations in Mono Lake effectively remained constant over 25 years despite the input stream concentrations increasing 6.5-fold. In contrast, Pyramid Lake concentrations increased approximately the expected amount based on a simplistic analysis of input flows and concentrations. An additional observation was that lakes in basins with agricultural activity appeared to have higher TFA concentrations, which suggests an agricultural input.
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Affiliation(s)
- Thomas M. Cahill
- School of Mathematical and Natural
Sciences, Arizona State University West Campus 4701 W Thunderbird Rd, Glendale, Arizona 85306, United States
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4
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Seo J, Ukani R, Zheng J, Braun JD, Wang S, Chen FE, Kim HK, Zhang S, Thai C, McGillicuddy RD, Yan H, Vlassak JJ, Mason JA. Barocaloric Effects in Dialkylammonium Halide Salts. J Am Chem Soc 2024; 146:2736-2747. [PMID: 38227768 DOI: 10.1021/jacs.3c12402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Barocaloric effects─solid-state thermal changes induced by the application and removal of hydrostatic pressure─offer the potential for energy-efficient heating and cooling without relying on volatile refrigerants. Here, we report that dialkylammonium halides─organic salts featuring bilayers of alkyl chains templated through hydrogen bonds to halide anions─display large, reversible, and tunable barocaloric effects near ambient temperature. The conformational flexibility and soft nature of the weakly confined hydrocarbons give rise to order-disorder phase transitions in the solid state that are associated with substantial entropy changes (>200 J kg-1 K-1) and high sensitivity to pressure (>24 K kbar-1), the combination of which drives strong barocaloric effects at relatively low pressures. Through high-pressure calorimetry, X-ray diffraction, and Raman spectroscopy, we investigate the structural factors that influence pressure-induced phase transitions of select dialkylammonium halides and evaluate the magnitude and reversibility of their barocaloric effects. Furthermore, we characterize the cyclability of thin-film samples under aggressive conditions (heating rate of 3500 K s-1 and over 11,000 cycles) using nanocalorimetry. Taken together, these results establish dialkylammonium halides as a promising class of pressure-responsive thermal materials.
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Affiliation(s)
- Jinyoung Seo
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Rahil Ukani
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Juanjuan Zheng
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Jason D Braun
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Sicheng Wang
- Department of Chemistry, University of North Texas, Denton, Texas 76203, United States
| | - Faith E Chen
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Hong Ki Kim
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Selena Zhang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Catherine Thai
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Ryan D McGillicuddy
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Hao Yan
- Department of Chemistry, University of North Texas, Denton, Texas 76203, United States
| | - Joost J Vlassak
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Jarad A Mason
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
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5
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McGillen MR, Fried ZTP, Khan MAH, Kuwata KT, Martin CM, O’Doherty S, Pecere F, Shallcross DE, Stanley KM, Zhang K. Ozonolysis can produce long-lived greenhouse gases from commercial refrigerants. Proc Natl Acad Sci U S A 2023; 120:e2312714120. [PMID: 38079548 PMCID: PMC10742373 DOI: 10.1073/pnas.2312714120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 10/30/2023] [Indexed: 12/24/2023] Open
Abstract
Hydrofluoroolefins are being adopted as sustainable alternatives to long-lived fluorine- and chlorine-containing gases and are finding current or potential mass-market applications as refrigerants, among a myriad of other uses. Their olefinic bond affords relatively rapid reaction with hydroxyl radicals present in the atmosphere, leading to short lifetimes and proportionally small global warming potentials. However, this type of functionality also allows reaction with ozone, and whilst these reactions are slow, we show that the products of these reactions can be extremely long-lived. Our chamber measurements show that several industrially important hydrofluoroolefins produce CHF3 (fluoroform, HFC-23), a potent, long-lived greenhouse gas. When this process is accounted for in atmospheric chemical and transport modeling simulations, we find that the total radiative effect of certain compounds can be several times that of the direct radiative effect currently recommended by the World Meteorological Organization. Our supporting quantum chemical calculations indicate that a large range of exothermicity is exhibited in the initial stages of ozonolysis, which has a powerful influence on the CHF3 yield. Furthermore, we identify certain molecular configurations that preclude the formation of long-lived greenhouse gases. This demonstrates the importance of product quantification and ozonolysis kinetics in determining the overall environmental impact of hydrofluoroolefin emissions.
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Affiliation(s)
- Max R. McGillen
- CNRS-Orléans, Institut de Combustion Aérothermique Réactivité et Environnement, Orléans45071, France
| | - Zachary T. P. Fried
- Department of Chemistry, Massachusetts Institute of Technology, Boston, MA02139
| | - M. Anwar H. Khan
- School of Chemistry, University of Bristol, BristolBS8 1TS, United Kingdom
| | - Keith T. Kuwata
- Department of Chemistry, Macalester College, Saint Paul, MN55105
| | - Connor M. Martin
- Department of Chemistry, University of California, Irvine, CA92697
| | - Simon O’Doherty
- School of Chemistry, University of Bristol, BristolBS8 1TS, United Kingdom
| | - Francesco Pecere
- Department of Chemistry, The Pennsylvania State University, State College, PA16801
| | | | - Kieran M. Stanley
- School of Chemistry, University of Bristol, BristolBS8 1TS, United Kingdom
| | - Kexin Zhang
- Department of Chemistry, Northwestern University, Evanston, IL60208
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6
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Wang Y, Liu L, Qiao X, Sun M, Guo J, Zhang J, Zhao B. Projections of National-Gridded Emissions of Hydrofluoroolefins (HFOs) in China. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:8650-8659. [PMID: 37235871 DOI: 10.1021/acs.est.2c09263] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Hydrofluoroolefins (HFOs) are being used as substitutes for potent greenhouse gas hydrofluorocarbons (HFCs). However, the use and environmental impacts of HFOs are of great concern due to the rapid degradation of HFOs to produce persistent and phytotoxic trifluoroacetic acid (TFA). Here, we provide a comprehensive projection of HFO emissions in China during 2024-2060 for the first time. Under the Kigali Amendment to the Montreal Protocol, China's HFO emissions are estimated to increase from 1.7 (1.3-2.3) to 148.8 (111.4-185.4) kt in 2024-2060 with cumulative emissions of 2.8 (2.0-3.5) Gt, and cumulative reduced HFCs emissions are evaluated to be 5.4 Gt CO2-equivalent. High HFO emissions would be distributed mainly in the North China Plain and the eastern and coastal areas. HFO-1234yf (2,3,3,3-tetrafluoropropene) contributes most of HFO emissions with a cumulative emission of 1.7 Gt in 2024-2060, while the cumulative increment of TFA deposition from HFO-1234yf emissions would reach 0.4-1.0 Gt. The long-term national-gridded HFO emission inventories can provide scientific support for evaluating the environmental risks of HFOs and developing HFC phase-out pathways for addressing climate change.
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Affiliation(s)
- Yifei Wang
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Lu Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Xueqi Qiao
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Mei Sun
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Junyu Guo
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Jianbo Zhang
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Bu Zhao
- School for Environment and Sustainability and Michigan Institute for Computational Discovery and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
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7
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Zhao L, Cheng Z, Zhu H, Chen H, Yao Y, Baqar M, Yu H, Qiao B, Sun H. Electronic-waste-associated pollution of per- and polyfluoroalkyl substances: Environmental occurrence and human exposure. JOURNAL OF HAZARDOUS MATERIALS 2023; 451:131204. [PMID: 36931218 DOI: 10.1016/j.jhazmat.2023.131204] [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: 12/16/2022] [Revised: 03/11/2023] [Accepted: 03/11/2023] [Indexed: 06/18/2023]
Abstract
Occupational exposure to per- and polyfluoroalkyl substances (PFASs) is of serious concern because their adverse health effects. Nevertheless, knowledge regarding contamination in e-waste dismantling regions is rather scarce. We therefore analysed seven neutral PFASs (n-PFASs) and forty ionized PFASs (i-PFASs) in dust and hand wipes collected from an e-waste dismantling plant and homes. Both dust (1370 ng/g) and workers' hand wipe (1100 ng/m2) in e-waste dismantling workshops contained significantly higher median levels of ∑PFASs than those from homes (684 ng/g and 444 ng/m2) (p < 0.01). ∑PFAS concentrations in dust and on workers' hand wipes from workshops were significantly higher than those from storage area. 8:2 fluorotelomer alcohol was the dominant n-PFAS in workshop dust (70.7%) and on worker's hand wipes (46.6%). Perfluoroalkyl carboxylic acids (C2 -C3) were the significant components (based on concentration) of i-PFASs in dust (57.9%) and on hand wipes (89.6%). A significant positive correlation (p < 0.001) of ∑PFAS concentrations between workshop dust and workers' hand wipes was observed, indicating that they come from common sources. Compared to dust ingestion, hand-to-mouth contact was highlighted as a vital exposure route, accounting for 68.8% for workers and 72.2% for residential population, respectively, of the sum of two exposure doses.
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Affiliation(s)
- Leicheng Zhao
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Zhipeng Cheng
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
| | - Hongkai Zhu
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Hao Chen
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Yiming Yao
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Mujtaba Baqar
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Hao Yu
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Biting Qiao
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Hongwen Sun
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
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8
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Harris KJ, Munoz G, Woo V, Sauvé S, Rand AA. Targeted and Suspect Screening of Per- and Polyfluoroalkyl Substances in Cosmetics and Personal Care Products. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:14594-14604. [PMID: 36178710 DOI: 10.1021/acs.est.2c02660] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemicals reported in cosmetics and personal care products as ingredients, possible impurities in the raw material manufacturing process, or degradation products. The purpose of this study was to further delineate contributions of these varying PFAS sources to these products. Thirty-eight cosmetics and personal care products were selected and analyzed for polyfluoroalkyl phosphates (PAPs), perfluoroalkyl carboxylic acids (PFCAs), fluorotelomer sulfonic acids (FTSAs), and perfluoroalkyl sulfonic acids (PFSAs) using targeted liquid chromatography tandem mass spectrometry (LC-MS/MS). A subset of products was also subjected to suspect screening using LC-high resolution mass spectrometry (HRMS) for >200 compounds. Results of LC-MS/MS and LC-HRMS indicated a predominant and ubiquitous presence of PAPs (detection frequency 99.7%, mean and median ΣPAPs 1 080 000 and 299 ng/g). Total median PFCA and PFSA concentrations were 3 and 38 times lower, respectively. There were significant correlations (Spearman's correlation coefficients = 0.60-0.81, p < 0.05) between 6:2 PAPs and their biotransformation products. Low levels of other PFAS classes were detected, including those previously measured in wastewater and human blood (e.g., hydrido-PFCAs), and five compounds associated with aqueous film-forming foams. Overall, these data highlight that cosmetics and personal care products can contain a breadth of PFAS at extremely high levels, leading to human and environmental exposure.
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Affiliation(s)
- Keegan J Harris
- Department of Chemistry and Institute of Biochemistry, Carleton University, Ottawa K1S 5B6, Canada
| | - Gabriel Munoz
- Department of Chemistry, University of Montréal, Montréal H2V 0B3, Canada
| | - Vivian Woo
- Department of Chemistry and Institute of Biochemistry, Carleton University, Ottawa K1S 5B6, Canada
| | - Sébastien Sauvé
- Department of Chemistry, University of Montréal, Montréal H2V 0B3, Canada
| | - Amy A Rand
- Department of Chemistry and Institute of Biochemistry, Carleton University, Ottawa K1S 5B6, Canada
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9
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Cahill TM. Increases in Trifluoroacetate Concentrations in Surface Waters over Two Decades. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:9428-9434. [PMID: 35736541 PMCID: PMC9261931 DOI: 10.1021/acs.est.2c01826] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/18/2022] [Accepted: 06/08/2022] [Indexed: 06/01/2023]
Abstract
Trifluoroacetate (TFA) is a persistent perfluorinated alkanoic acid anion that has many anthropogenic sources, with fluorocarbon refrigerants being a major one. After an initial burst of research in the late 1990s and early 2000s, research on this ubiquitous pollutant declined as atmospheric emissions of the precursor compounds grew rapidly. Thus, there is little contemporaneous information about the concentrations of TFA in the environment and how they have changed over time. This research determined the change in TFA concentrations in streams by resampling a transect that was originally sampled in 1998. The transect was designed to determine the regional distribution of TFA both upwind and downwind of major metropolitan areas in Northern California as well as a set of globally remote sites in Alaska. The results showed that TFA concentrations increased by an average of 6-fold over the intervening 23 years, which resulted in a median concentration of 180 ng/L (range 21.3-2790). The highest concentrations were found in streams immediately downwind of the San Francisco Bay Area, while substantially lower concentrations were found in the upwind, regionally remote, and globally remote sites. The C3 to C5 perfluorinated alkanoic acids were also investigated, but they were rarely detected with this methodology.
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10
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Sosa J, Santiago R, Redondo AE, Avila J, Lepre LF, Gomes MC, Araújo JM, Palomar J, Pereiro AB. Design of Ionic Liquids for Fluorinated Gas Absorption: COSMO-RS Selection and Solubility Experiments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5898-5909. [PMID: 35435682 PMCID: PMC9069701 DOI: 10.1021/acs.est.2c00051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/14/2022] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
In recent years, the fight against climate change and the mitigation of the impact of fluorinated gases (F-gases) on the atmosphere is a global concern. Development of technologies that help to efficiently separate and recycle hydrofluorocarbons (HFCs) at the end of the refrigeration and air conditioning equipment life is a priority. The technological development is important to stimulate the F-gas capture, specifically difluoromethane (R-32) and 1,1,1,2-tetrafluoroethane (R-134a), due to their high global warming potential. In this work, the COSMO-RS method is used to analyze the solute-solvent interactions and to determine Henry's constants of R-32 and R-134a in more than 600 ionic liquids. The three most performant ionic liquids were selected on the basis of COSMO-RS calculations, and F-gas absorption equilibrium isotherms were measured using gravimetric and volumetric methods. Experimental results are in good agreement with COSMO-RS predictions, with the ionic liquid tributyl(ethyl)phosphonium diethyl phosphate, [P2444][C2C2PO4], being the salt presenting the highest absorption capacities in molar and mass units compared to salts previously tested. The other two ionic liquids selected, trihexyltetradecylphosphonium glycinate, [P66614][C2NO2], and trihexyl(tetradecyl)phosphonium 2-cyano-pyrrole, [P66614][CNPyr], may be competitive as far as their absorption capacities are concerned. Future works will be guided on evaluating the performance of these ionic liquids at an industrial scale by means of process simulations, in order to elucidate the role in process efficiency of other relevant absorbent properties such as viscosity, molar weight, or specific heat.
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Affiliation(s)
- Julio
E. Sosa
- LAQV,
REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, Caparica 2829-516, Portugal
| | - Rubén Santiago
- Chemical
Engineering Department, Universidad Autónoma
de Madrid, Madrid 28049, Spain
| | - Andres E. Redondo
- LAQV,
REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, Caparica 2829-516, Portugal
| | - Jocasta Avila
- Laboratoire
de Chimie, École Normale Superieure de Lyon & CNRS, Lyon 69364, France
| | - Luiz F. Lepre
- Laboratoire
de Chimie, École Normale Superieure de Lyon & CNRS, Lyon 69364, France
| | | | - João M.
M. Araújo
- LAQV,
REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, Caparica 2829-516, Portugal
| | - José Palomar
- Chemical
Engineering Department, Universidad Autónoma
de Madrid, Madrid 28049, Spain
| | - Ana B. Pereiro
- LAQV,
REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, Caparica 2829-516, Portugal
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11
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Björnsdotter MK, Yeung LWY, Kärrman A, Jogsten IE. Mass Balance of Perfluoroalkyl Acids, Including Trifluoroacetic Acid, in a Freshwater Lake. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:251-259. [PMID: 34927432 PMCID: PMC8733927 DOI: 10.1021/acs.est.1c04472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 11/28/2021] [Accepted: 12/05/2021] [Indexed: 06/02/2023]
Abstract
Perfluoroalkyl acids (PFAAs) are highly persistent chemicals that are ubiquitously found in the environment. The atmospheric degradation of precursor compounds has been identified as a source of PFAAs and might be an important pathway for contamination. Lake Vättern is one of Sweden's largest lakes and is an important source for drinking water. In addition to contamination via atmospheric deposition, the lake is subject to several potential contamination sources via surface water inflow. The relevance of different sources is not well understood. A mass balance of selected PFAAs was assembled based on measured concentrations in atmospheric deposition, surface water from streams that constitute the main inflow and outflow, and surface water in the lake. The largest input was seen for trifluoroacetic acid (150 kg/year), perfluoropropanoic acid (1.6 kg/year), perfluorobutanoic acid (4.0 kg/year), and perfluoro-octanoic acid (1.5 kg/year). Both atmospheric deposition and surface water inflow was found to be important input pathways. There was a positive correlation between the input of most perfluoroalkyl carboxylic acids via atmospheric deposition and global radiation and between the input via surface water inflow and catchment area. These findings highlight the importance of atmospheric oxidation of volatile precursor compounds for contamination in surface waters.
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12
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Flerlage H, Velders GJM, de Boer J. A review of bottom-up and top-down emission estimates of hydrofluorocarbons (HFCs) in different parts of the world. CHEMOSPHERE 2021; 283:131208. [PMID: 34153914 DOI: 10.1016/j.chemosphere.2021.131208] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 06/07/2021] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
Hydrofluorocarbons (HFCs) are widespread alternatives for the ozone-depleting substances chlorofluorocarbons and hydrochlorofluorocarbons. They are used mainly as refrigerants or as foam-blowing agents. HFCs do not deplete the ozone layer, but they are very potent greenhouse gases, already contributing to global warming. Since 2019 HFCs are regulated under the Kigali Amendment to the Montreal Protocol, which demands reliable emission estimates to monitor the phase-down. Quantification of emissions is performed with two methods: bottom-up from product inventories or data on chemical sales; or top-down, inferred from atmospheric measurements by inverse modelling or interspecies correlation. Here, we review and compare the two methods and give an overview of HFC emissions from different parts of the world. Emission estimates reported by the different methods vary considerably. HFC emissions of developed countries (Annex I) are reported to the United Nations Framework Convention on Climate Change. These bottom-up estimates add up to only half of global emissions estimated from atmospheric data. Several studies with regional top-down estimates have shown that this gap is not owed to large-scale underreporting of emissions from developed countries, but mostly due to emissions from developing countries (non-Annex I). China accounts for a large fraction of the emissions causing the gap, but not entirely. Bottom-up and top-down estimations of emissions from other developing countries that could identify other large emitters are largely unavailable. Especially South America, West-, Central- and East-Africa, India, the Arabian Peninsula and Northern Australia are not well covered by measurement stations that could provide atmospheric data for top-down estimates.
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Affiliation(s)
- Hannah Flerlage
- Vrije Universiteit, Department of Environment and Health, Faculty of Sciences, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands.
| | - Guus J M Velders
- National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht University, the Netherlands
| | - Jacob de Boer
- Vrije Universiteit, Department of Environment and Health, Faculty of Sciences, De Boelelaan 1085, 1081 HV, Amsterdam, the Netherlands
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13
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Wang Y, Wang Z, Sun M, Guo J, Zhang J. Emissions, degradation and impact of HFO-1234ze from China PU foam industry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 780:146631. [PMID: 34030310 DOI: 10.1016/j.scitotenv.2021.146631] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/26/2021] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
Currently used foam agent HCFC-141b was undergoing phased out worldwide with the implementation of the Montreal Protocol. HFO-1234ze was proposed as replacement in polyurethane (PU) foam industry with shorter atmospheric lifetime. This paper calculated historical and future emissions of HCFC-141b and HFO-1234ze till 2050, used GEOS-Chem under two HFO-1234ze emission scenarios to track its atmospheric process and distribution, and to assess its potential environmental effects. Results showed that annual HCFC-141b emissions for 2015, 2019 and 2050 were 12.6 Gg/yr, 21.0 Gg/yr and 7.6 Gg/yr, respectively and emissions of HFO-1234ze would reach 124.4 Gg/yr by 2050. Under Scenario I with HFO-1234ze emissions of 12.6 Gg/yr as input, annual mixing ratios of HFO-1234ze and its products CF3CHO and HCOF were 10.47, 2.68 and 1.74 pptv for China, and were 0.55, 0.18 and 0.1 pptv globally, respectively, suggesting the regional aggregation of these substances in emission areas. HCOF were removed from atmosphere by depositions, with total deposition rates of 22.06 g km-1 y-1 in CH, and 1.15 g km-1 y-1 in globe. Under Scenario II with HFO-1234ze emissions of 124.4 Gg/yr as input, annual mixing ratios of HFO-1234ze, CF3CHO and HCOF, along with HCOF total deposition rates were 102.98 26.36 and 17.17 pptv and 217 g km-1 y-1 in China, respectively, increased linearly to HFO-1234ze emissions change. The mixing ratios of HFO-1234ze and HCOF were too small to exert significant effects on current atmosphere burden and circulation, while CF3CHO might potentially involve in aminolysis reaction under future emissions of HFO-1234ze.
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Affiliation(s)
- Yifei Wang
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Ziyuan Wang
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Mei Sun
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Junyu Guo
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| | - Jianbo Zhang
- State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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D’Ambro EL, Pye HOT, Bash JO, Bowyer J, Allen C, Efstathiou C, Gilliam RC, Reynolds L, Talgo K, Murphy BN. Characterizing the Air Emissions, Transport, and Deposition of Per- and Polyfluoroalkyl Substances from a Fluoropolymer Manufacturing Facility. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:862-870. [PMID: 33395278 PMCID: PMC7887699 DOI: 10.1021/acs.est.0c06580] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) have been released into the environment for decades, yet contributions of air emissions to total human exposure, from inhalation and drinking water contamination via deposition, are poorly constrained. The atmospheric transport and fate of a PFAS mixture from a fluoropolymer manufacturing facility in North Carolina were investigated with the Community Multiscale Air Quality (CMAQ) model applied at high resolution (1 km) and extending ∼150 km from the facility. Twenty-six explicit PFAS compounds, including GenX, were added to CMAQ using current best estimates of air emissions and relevant physicochemical properties. The new model, CMAQ-PFAS, predicts that 5% by mass of total emitted PFAS and 2.5% of total GenX are deposited within ∼150 km of the facility, with the remainder transported out. Modeled air concentrations of total GenX and total PFAS around the facility can reach 24.6 and 8500 ng m-3 but decrease to ∼0.1 and ∼10 ng m-3 at 35 km downwind, respectively. We find that compounds with acid functionality have higher deposition due to enhanced water solubility and pH-driven partitioning to aqueous media. To our knowledge, this is the first modeling study of the fate of a comprehensive, chemically resolved suite of PFAS air emissions from a major manufacturing source.
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Affiliation(s)
- Emma L. D’Ambro
- Oak Ridge Institute for Science Education, Oak Ridge, TN
- Center for Environmental Measurement and Modeling, U.S. EPA, Research Triangle Park, NC
| | - Havala O. T. Pye
- Center for Environmental Measurement and Modeling, U.S. EPA, Research Triangle Park, NC
| | - Jesse O. Bash
- Center for Environmental Measurement and Modeling, U.S. EPA, Research Triangle Park, NC
| | - James Bowyer
- North Carolina Division of Air Quality, NC DEQ, Raleigh, NC
| | - Chris Allen
- General Dynamics Information Technology, Research Triangle Park, NC
| | | | - Robert C. Gilliam
- Center for Environmental Measurement and Modeling, U.S. EPA, Research Triangle Park, NC
| | - Lara Reynolds
- General Dynamics Information Technology, Research Triangle Park, NC
| | - Kevin Talgo
- General Dynamics Information Technology, Research Triangle Park, NC
| | - Benjamin N. Murphy
- Center for Environmental Measurement and Modeling, U.S. EPA, Research Triangle Park, NC
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15
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Sun M, Cui J, Guo J, Zhai Z, Zuo P, Zhang J. Fluorochemicals biodegradation as a potential source of trifluoroacetic acid (TFA) to the environment. CHEMOSPHERE 2020; 254:126894. [PMID: 32957292 DOI: 10.1016/j.chemosphere.2020.126894] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/23/2020] [Accepted: 04/23/2020] [Indexed: 05/05/2023]
Abstract
The anthropogenic release of trifluoroacetic acid (TFA) into the environmental media is not limited to photochemical oxidation of CFC alternatives and industrial emissions. Biological degradation of some fluorochemicals is expected to be a potential TFA source. For the first time, we assess if the potential precursors [6:2 fluorotelomer alcohol (6:2 FTOH), 4:2 fluorotelomer alcohol (4:2 FTOH), acrinathrin, trifluralin, and 2-(trifluoromethyl)acrylic acid (TFMAA)] can be biologically degraded to TFA. Results show that 6:2 FTOH was terminally transformed to 5:3 polyfluorinated acid (5:3 FTCA; 12.5 mol%), perfluorohexanoic acid (PFHxA; 2.0 mol%), perfluoropentanoic acid (PFPeA; 1.6 mol%), perfluorobutyric acid (PFBA; 1.7 mol%), and TFA (2.3 mol%) by day 32 in the landfill soil microbial culture system. 4:2 FTOH could remove multiple -CF2 groups by microorganisms and produce PFPeA (2.6 mol%), PFBA (17.4 mol%), TFA (7.8 mol%). We also quantified the degradation products of TFMAA as PFBA (1.3 mol%) and TFA (6.3 mol%). Furthermore, we basically analyzed the biodegradation contribution of short-chain FTOH as raw material residuals in commercial products to the TFA burden in the environmental media. We estimate global emission of 3.9-47.3 tonnes of TFA in the period from 1961 to 2019, and project 3.8-46.4 tonnes to be emitted from 2020 to 2040 via the pathway of 4:2 and 6:2 FTOH biodegradation (0.6-7.1 and 0.6-7.0 tonnes in China, respectively). Direct evidence of the experiments indicates that biodegradation of fluorochemicals is an overlooked source of TFA and there are still some unspecified mechanisms of TFA production pathways.
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Affiliation(s)
- Mei Sun
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Jia'nan Cui
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Junyu Guo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
| | - Zihan Zhai
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China; Land Consolidation and Rehabilitation Center, The Ministry of Land and Resources, Beijing, 100035, China
| | - Peng Zuo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Jianbo Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
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16
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Lv K, Gao W, Meng L, Xue Q, Tian H, Wang Y, Jiang G. Phototransformation of perfluorooctane sulfonamide on natural clay minerals: A likely source of short chain perfluorocarboxylic acids. JOURNAL OF HAZARDOUS MATERIALS 2020; 392:122354. [PMID: 32097861 DOI: 10.1016/j.jhazmat.2020.122354] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/02/2020] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
In this study, a new phototransformation pathway for perfluorooctane sulfonamide (FOSA) and underlying degradation mechanisms are described. Phototransformation of FOSA in a natural clay mineral (montmorillonite) suspension was compared to that in an aqueous solution. Results showed that the presence of montmorillonite can significantly promote the transformation of FOSA to perfluocarboxylic acids (increasing rate). The phototransformation reaction was found to be initiated by the activation of adsorbed oxygen molecules on the surface of montmorillonite, which generate superoxide anion and hydroxyl radicals. Hydroxyl radicals can then attack FOSA adsorbed onto the surface of montmorillonite, promoting the transformation process. In this reaction, clay minerals played a dual role: providing hydroxyl radicals and concentrating FOSA on their surfaces. This helped to promote the contact and reaction between FOSA and hydroxyl radicals. This study provides the first evidence that heterogeneous oxidation of FOSA at the surface of natural clay minerals may act as an important source of perfluocarboxylic acids (PFCAs), especially short chain PFCAs (i.e. trifluoroacetic acid, TFA).
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Affiliation(s)
- Kun Lv
- Environment Research Institute, Shandong University, Qingdao, 266237, China; State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Wei Gao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Lingyi Meng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qiao Xue
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Haoting Tian
- Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection, College of Resource and Environment, Linyi University, Linyi, 276005, China.
| | - Yawei Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
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17
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Bernhard GH, Neale RE, Barnes PW, Neale PJ, Zepp RG, Wilson SR, Andrady AL, Bais AF, McKenzie RL, Aucamp PJ, Young PJ, Liley JB, Lucas RM, Yazar S, Rhodes LE, Byrne SN, Hollestein LM, Olsen CM, Young AR, Robson TM, Bornman JF, Jansen MAK, Robinson SA, Ballaré CL, Williamson CE, Rose KC, Banaszak AT, Häder DP, Hylander S, Wängberg SÅ, Austin AT, Hou WC, Paul ND, Madronich S, Sulzberger B, Solomon KR, Li H, Schikowski T, Longstreth J, Pandey KK, Heikkilä AM, White CC. Environmental effects of stratospheric ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2019. Photochem Photobiol Sci 2020; 19:542-584. [PMID: 32364555 PMCID: PMC7442302 DOI: 10.1039/d0pp90011g] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 03/23/2020] [Indexed: 12/24/2022]
Abstract
This assessment, by the United Nations Environment Programme (UNEP) Environmental Effects Assessment Panel (EEAP), one of three Panels informing the Parties to the Montreal Protocol, provides an update, since our previous extensive assessment (Photochem. Photobiol. Sci., 2019, 18, 595-828), of recent findings of current and projected interactive environmental effects of ultraviolet (UV) radiation, stratospheric ozone, and climate change. These effects include those on human health, air quality, terrestrial and aquatic ecosystems, biogeochemical cycles, and materials used in construction and other services. The present update evaluates further evidence of the consequences of human activity on climate change that are altering the exposure of organisms and ecosystems to UV radiation. This in turn reveals the interactive effects of many climate change factors with UV radiation that have implications for the atmosphere, feedbacks, contaminant fate and transport, organismal responses, and many outdoor materials including plastics, wood, and fabrics. The universal ratification of the Montreal Protocol, signed by 197 countries, has led to the regulation and phase-out of chemicals that deplete the stratospheric ozone layer. Although this treaty has had unprecedented success in protecting the ozone layer, and hence all life on Earth from damaging UV radiation, it is also making a substantial contribution to reducing climate warming because many of the chemicals under this treaty are greenhouse gases.
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Affiliation(s)
- G H Bernhard
- Biospherical Instruments Inc., San Diego, California, USA
| | - R E Neale
- Population Health Department, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - P W Barnes
- Biological Sciences and Environment Program, Loyola University, New Orleans, USA
| | - P J Neale
- Smithsonian Environmental Research Center, Edgewater, Maryland, USA
| | - R G Zepp
- United States Environmental Protection Agency, Athens, Georgia, USA
| | - S R Wilson
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, Australia
| | - A L Andrady
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - A F Bais
- Department of Physics, Aristotle University of Thessaloniki, Greece
| | - R L McKenzie
- National Institute of Water & Atmospheric Research, Lauder, Central Otago, New Zealand
| | - P J Aucamp
- Ptersa Environmental Consultants, Faerie Glen, South Africa
| | - P J Young
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - J B Liley
- National Institute of Water & Atmospheric Research, Lauder, Central Otago, New Zealand
| | - R M Lucas
- National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australia
| | - S Yazar
- Garvan Institute of Medical Research, Sydney, Australia
| | - L E Rhodes
- Faculty of Biology Medicine and Health, University of Manchester, and Salford Royal Hospital, Manchester, UK
| | - S N Byrne
- School of Medical Sciences, University of Sydney, Sydney, Australia
| | - L M Hollestein
- Erasmus MC, University Medical Center Rotterdam, Manchester, The Netherlands
| | - C M Olsen
- Population Health Department, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - A R Young
- St John's Institute of Dermatology, King's College, London, London, UK
| | - T M Robson
- Organismal & Evolutionary Biology, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland
| | - J F Bornman
- Food Futures Institute, Murdoch University, Perth, Australia.
| | - M A K Jansen
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
| | - S A Robinson
- Centre for Sustainable Ecosystem Solutions, University of Wollongong, Wollongong, Australia
| | - C L Ballaré
- Faculty of Agronomy and IFEVA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
| | - C E Williamson
- Department of Biology, Miami University, Oxford, Ohio, USA
| | - K C Rose
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - A T Banaszak
- Unidad Académica de Sistemas Arrecifales, Universidad Nacional Autónoma de México, Puerto Morelos, Mexico
| | - D -P Häder
- Department of Biology, Friedrich-Alexander University, Möhrendorf, Germany
| | - S Hylander
- Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
| | - S -Å Wängberg
- Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden
| | - A T Austin
- Faculty of Agronomy and IFEVA-CONICET, University of Buenos Aires, Buenos Aires, Argentina
| | - W -C Hou
- Department of Environmental Engineering, National Cheng Kung University, Tainan City, Taiwan, China
| | - N D Paul
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - S Madronich
- National Center for Atmospheric Research, Boulder, Colorado, USA
| | - B Sulzberger
- Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | - K R Solomon
- Centre for Toxicology, School of Environmental Sciences, University of Guelph, Guelph, Canada
| | - H Li
- Institute of Atmospheric Environment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - T Schikowski
- Research Group of Environmental Epidemiology, Leibniz Institute of Environmental Medicine, Düsseldorf, Germany
| | - J Longstreth
- Institute for Global Risk Research, Bethesda, Maryland, USA
| | - K K Pandey
- Institute of Wood Science and Technology, Bengaluru, India
| | - A M Heikkilä
- Finnish Meteorological Institute, Helsinki, Finland
| | - C C White
- , 5409 Mohican Rd, Bethesda, Maryland, USA
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18
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Challenges in the analytical determination of ultra-short-chain perfluoroalkyl acids and implications for environmental and human health. Anal Bioanal Chem 2020; 412:4785-4796. [PMID: 32399685 PMCID: PMC7334270 DOI: 10.1007/s00216-020-02692-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 04/17/2020] [Accepted: 04/30/2020] [Indexed: 11/23/2022]
Abstract
Ultra-short-chain perfluoroalkyl acids have recently gained attention due to increasing environmental concentrations being observed. The most well-known ultra-short-chain perfluoroalkyl acid is trifluoroacetic acid (TFA) which has been studied since the 1990s. Potential sources and the fate of ultra-short-chain perfluoroalkyl acids other than TFA are not well studied and data reporting their environmental occurrence is scarce. The analytical determination of ultra-short-chain perfluoroalkyl acids is challenging due to their high polarity resulting in low retention using reversed-phase liquid chromatography. Furthermore, recent studies have reported varying extraction recoveries in water samples depending on the water matrix and different methods have been suggested to increase the extraction recovery. The present review gives an overview of the currently used analytical methods and summarizes the findings regarding potential analytical challenges. In addition, the current state of knowledge regarding TFA and other ultra-short-chain perfluoroalkyl acids, namely perfluoropropanoic acid, trifluoromethane sulfonic acid, perfluoroethane sulfonic acid, and perfluoropropane sulfonic acid‚ are reviewed. Both known and potential sources as well as environmental concentrations are summarized and discussed together with their fate and the environmental and human implications.
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Cousins IT, Goldenman G, Herzke D, Lohmann R, Miller M, Ng CA, Patton S, Scheringer M, Trier X, Vierke L, Wang Z, DeWitt JC. The concept of essential use for determining when uses of PFASs can be phased out. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:1803-1815. [PMID: 31204421 PMCID: PMC6992415 DOI: 10.1039/c9em00163h] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Because of the extreme persistence of per- and polyfluoroalkyl substances (PFASs) and their associated risks, the Madrid Statement argues for stopping their use where they are deemed not essential or when safer alternatives exist. To determine when uses of PFASs have an essential function in modern society, and when they do not, is not an easy task. Here, we: (1) develop the concept of "essential use" based on an existing approach described in the Montreal Protocol, (2) apply the concept to various uses of PFASs to determine the feasibility of elimination or substitution of PFASs in each use category, and (3) outline the challenges for phasing out uses of PFASs in society. In brief, we developed three distinct categories to describe the different levels of essentiality of individual uses. A phase-out of many uses of PFASs can be implemented because they are not necessary for the betterment of society in terms of health and safety, or because functional alternatives are currently available that can be substituted into these products or applications. Some specific uses of PFASs would be considered essential because they provide for vital functions and are currently without established alternatives. However, this essentiality should not be considered as permanent; rather, constant efforts are needed to search for alternatives. We provide a description of several ongoing uses of PFASs and discuss whether these uses are essential or non-essential according to the three essentiality categories. It is not possible to describe each use case of PFASs in detail in this single article. For follow-up work, we suggest further refining the assessment of the use cases of PFASs covered here, where necessary, and expanding the application of this concept to all other uses of PFASs. The concept of essential use can also be applied in the management of other chemicals, or groups of chemicals, of concern.
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Affiliation(s)
- Ian T Cousins
- Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University, SE-10691, Sweden.
| | | | - Dorte Herzke
- NILU, Norwegian Institute for Air Research, Tromsø, Norway
| | - Rainer Lohmann
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, USA
| | - Mark Miller
- National Institute of Environmental Health Sciences, U.S. Public Health Service, Research Triangle Park, NC, USA
| | - Carla A Ng
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | | | - Martin Scheringer
- Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, 8092 Zürich, Switzerland
| | - Xenia Trier
- DTU Technical University of Denmark, Copenhagen, Denmark
| | - Lena Vierke
- German Environment Agency (UBA), Dessau-Roßlau, Germany
| | - Zhanyun Wang
- Chair of Ecological Systems Design, Institute of Environmental Engineering, ETH Zürich, 8093 Zürich, Switzerland
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20
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Berasategui M, Argüello GA, Burgos Paci MA. Gas-Phase Reaction between CF 2O and CF 3C(O)OH: Characterization of CF 3C(O)OC(O)F. J Phys Chem A 2019; 123:4671-4678. [PMID: 31046279 DOI: 10.1021/acs.jpca.9b00899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The thermal decomposition of trifluoroacetic acid and carbonyl fluoride (CF2O) has been extensively studied because of their importance in the oxidation of hydrochlorofluorocarbons in the atmosphere. We hitherto present the study of the thermal reaction between these two molecules. The reaction mechanism was studied using Fourier transform infrared spectroscopy in the temperature range of 513-573 K. The reaction proceeds homogeneously in the gas phase through the formation of a reaction intermediate, here characterized as CF3C(O)OC(O)F (detected for the first time in this work), the major final products being CF3C(O)F, HF, and CO2. We demonstrate that the reaction is first-order with respect to each reagent, second-order global and the mechanism consists of two steps, the first being the rate-determining one. The Ea = 110.1 ± 6.1 kJ mol-1 and A = (1.2 ± 0.2) × 10-12 cm3 molec-1 s-1 values were obtained from the experimental data. The low activation energy is explained by the hydrogen-bond interactions between the -OH group of the acid and the F atom of the CF2O. First-principles calculations at the G4MP2 level of theory were carried out to understand the dynamics of the decomposition. Thermodynamic activation values found for this reaction are as follows: Δ H⧧ = 105.6 ± 6.4 kJ mol-1, Δ S⧧ = -88.6 ± 9.7 J mol-1 K-1, and Δ G⧧ = 153.7 ± 13.5 kJ mol-1. The comparison between theory and experimental results showed excellent similarities, thus strengthening the proposed mechanism.
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Affiliation(s)
- Matias Berasategui
- Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) CONICET-UNC, Departamento de Físico Química, Facultad de Ciencias Químicas , Universidad Nacional de Córdoba , Ciudad Universitaria , X5000HUA Córdoba , Argentina
| | - Gustavo A Argüello
- Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) CONICET-UNC, Departamento de Físico Química, Facultad de Ciencias Químicas , Universidad Nacional de Córdoba , Ciudad Universitaria , X5000HUA Córdoba , Argentina
| | - Maxi A Burgos Paci
- Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) CONICET-UNC, Departamento de Físico Química, Facultad de Ciencias Químicas , Universidad Nacional de Córdoba , Ciudad Universitaria , X5000HUA Córdoba , Argentina
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Cui J, Guo J, Zhai Z, Zhang J. The contribution of fluoropolymer thermolysis to trifluoroacetic acid (TFA) in environmental media. CHEMOSPHERE 2019; 222:637-644. [PMID: 30731384 DOI: 10.1016/j.chemosphere.2019.01.174] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 01/27/2019] [Accepted: 01/29/2019] [Indexed: 06/09/2023]
Abstract
The source of trifluoroacetic acid (TFA) has long been a controversial issue. Fluoropolymer thermolysis is expected to be a potential anthropogenic source except for CFC alternatives. However, its TFA yield and contributions have rarely been reported more recently. In this study, we investigated the thermal properties of three kinds of fluoropolymers, including poly (vinylidene fluoride-co-hexafluropropylene) (PVDF-HFP), poly (vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) and poly (tetrafluoroethylene) (PTFE). A laboratory simulation experiment was then performed to analyze the TFA levels in the thermolysis products and hence to examine the TFA yields of these fluoropolymers. Thermolysis of these fluoropolymers occurred in the temperature ranges from ∼400 °C to ∼650 °C, with the peak weight loss rate at around 550-600 °C. TFA could be produced through fluoropolymer thermolysis when being heated to 500 °C and above. Average TFA yields of PTFE, PVDF-HFP and PVDF-CTFE were 1.2%, 0.9% and 0.3%, respectively. Furthermore, the contribution of fluoropolymer thermolysis and CFC alternatives to rainwater TFA in Beijing, China was evaluated by using a Two-Box model. The degradation of fluoropolymers and HCFCs/HFCs could explain 37.9-43.4 ng L-1 rainwater TFA in Beijing in 2014. The thermolysis of fluoropolymers contributed 0.6-6.1 ng L-1 of rainwater TFA, accounting for 1.6-14.0% of the TFA burden from all the precursors which were considered here.
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Affiliation(s)
- Jia'nan Cui
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Junyu Guo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China
| | - Zihan Zhai
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China; Land Consolidation and Rehabilitation Center, The Ministry of Land and Resources, Beijing, 100035, China
| | - Jianbo Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
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Bentel MJ, Yu Y, Xu L, Li Z, Wong BM, Men Y, Liu J. Defluorination of Per- and Polyfluoroalkyl Substances (PFASs) with Hydrated Electrons: Structural Dependence and Implications to PFAS Remediation and Management. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3718-3728. [PMID: 30874441 DOI: 10.1021/acs.est.8b06648] [Citation(s) in RCA: 183] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This study investigates critical structure-reactivity relationships within 34 representative per- and polyfluoroalkyl substances (PFASs) undergoing defluorination with UV-generated hydrated electrons. While C nF2 n+1-COO- with variable fluoroalkyl chain lengths ( n = 2 to 10) exhibited a similar rate and extent of parent compound decay and defluorination, the reactions of telomeric C nF2 n+1-CH2CH2-COO- and C nF2 n+1-SO3- showed an apparent dependence on the length of the fluoroalkyl chain. Cross comparison of experimental results, including different rates of decay and defluorination of specific PFAS categories, the incomplete defluorination from most PFAS structures, and the surprising 100% defluorination from CF3COO-, leads to the elucidation of new mechanistic insights into PFAS degradation. Theoretical calculations on the C-F bond dissociation energies (BDEs) of all PFAS structures reveal strong relationships among (i) the rate and extent of decay and defluorination, (ii) head functional groups, (iii) fluoroalkyl chain length, and (iv) the position and number of C-F bonds with low BDEs. These relationships are further supported by the spontaneous cleavage of specific bonds during calculated geometry optimization of PFAS structures bearing one extra electron, and by the product analyses with high-resolution mass spectrometry. Multiple reaction pathways, including H/F exchange, dissociation of terminal functional groups, and decarboxylation-triggered HF elimination and hydrolysis, result in the formation of variable defluorination products. The selectivity and ease of C-F bond cleavage highly depends on molecular structures. These findings provide critical information for developing PFAS treatment processes and technologies to destruct a wide scope of PFAS pollutants and for designing fluorochemical formulations to avoid releasing recalcitrant PFASs into the environment.
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Affiliation(s)
- Michael J Bentel
- Department of Chemical & Environmental Engineering and ‡Materials Science & Engineering Program , University of California , Riverside , California 92521 , United States
| | - Yaochun Yu
- Department of Civil & Environmental Engineering , ∥Metabolomics Lab of Roy J. Carver Biotechnology Center , and ⊥Institute for Genomic Biology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Lihua Xu
- Department of Chemical & Environmental Engineering and ‡Materials Science & Engineering Program , University of California , Riverside , California 92521 , United States
| | | | - Bryan M Wong
- Department of Chemical & Environmental Engineering and ‡Materials Science & Engineering Program , University of California , Riverside , California 92521 , United States
| | - Yujie Men
- Department of Civil & Environmental Engineering , ∥Metabolomics Lab of Roy J. Carver Biotechnology Center , and ⊥Institute for Genomic Biology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Jinyong Liu
- Department of Chemical & Environmental Engineering and ‡Materials Science & Engineering Program , University of California , Riverside , California 92521 , United States
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23
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Wilson SR, Madronich S, Longstreth JD, Solomon KR. Interactive effects of changing stratospheric ozone and climate on tropospheric composition and air quality, and the consequences for human and ecosystem health. Photochem Photobiol Sci 2019; 18:775-803. [PMID: 30810564 DOI: 10.1039/c8pp90064g] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The composition of the air we breathe is determined by emissions, weather, and photochemical transformations induced by solar UV radiation. Photochemical reactions of many emitted chemical compounds can generate important (secondary) pollutants including ground-level ozone (O3) and some particulate matter, known to be detrimental to human health and ecosystems. Poor air quality is the major environmental cause of premature deaths globally, and even a small decrease in air quality can translate into a large increase in the number of deaths. In many regions of the globe, changes in emissions of pollutants have caused significant changes in air quality. Short-term variability in the weather as well as long-term climatic trends can affect ground-level pollution through several mechanisms. These include large-scale changes in the transport of O3 from the stratosphere to the troposphere, winds, clouds, and patterns of precipitation. Long-term trends in UV radiation, particularly related to the depletion and recovery of stratospheric ozone, are also expected to result in changes in air quality as well as the self-cleaning capacity of the global atmosphere. The increased use of substitutes for ozone-depleting substances, in response to the Montreal Protocol, does not currently pose a significant risk to the environment. This includes both the direct emissions of substitutes during use and their atmospheric degradation products (e.g. trifluoroacetic acid, TFA).
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Affiliation(s)
- S R Wilson
- Centre for Atmospheric Chemistry, School of Earth, Atmosphere and Life Sciences, University of Wollongong, NSW, Australia.
| | - S Madronich
- National Center for Atmospheric Research, Boulder, CO, USA
| | - J D Longstreth
- The Institute for Global Risk Research, LLC, Bethesda, MD, USA and Emergent BioSolutions, Gaithersburg, MD, USA
| | - K R Solomon
- Centre for Toxicology and School of Environmental Sciences, University of Guelph, ON, Canada
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24
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Huff AK, Mackenzie RB, Smith CJ, Leopold KR. A Perfluorinated Carboxylic Sulfuric Anhydride: Microwave and Computational Studies of CF3COOSO2OH. J Phys Chem A 2019; 123:2237-2243. [DOI: 10.1021/acs.jpca.9b00300] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Anna K. Huff
- Department of Chemistry, University of Minnesota, 207 Pleasant Street, SE, Minneapolis, Minnesota 55455, United States
| | - Rebecca B. Mackenzie
- Department of Chemistry, University of Minnesota, 207 Pleasant Street, SE, Minneapolis, Minnesota 55455, United States
| | - C. J. Smith
- Department of Chemistry, University of Minnesota, 207 Pleasant Street, SE, Minneapolis, Minnesota 55455, United States
| | - Kenneth R. Leopold
- Department of Chemistry, University of Minnesota, 207 Pleasant Street, SE, Minneapolis, Minnesota 55455, United States
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