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Pem B, Vazdar M, Bakarić D. Elucidation of the hydration pattern of trifluoroacetic acid in dilute solutions: FTIR and computational study. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 323:124900. [PMID: 39098294 DOI: 10.1016/j.saa.2024.124900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2024] [Accepted: 07/28/2024] [Indexed: 08/06/2024]
Abstract
The atmospheric partitioning of trifluoroacetic acid (TFA) in aerosol is a complex function of the size of suspended water droplets and their pH value. The unraveling of the affinity of TFA towards basic but not acidic conditions may be accomplished by providing an insight into the hydration pattern of undissociated TFA. Owing to rather scarce details on very dilute aqueous solutions of trifluoroacetic acid (TFA), we examined CF3COOD and CF3COONa solutions in D2O in the concentration range 0.001-0.1 mol dm-3 using transmission FTIR spectroscopy and computational methods. Besides detecting the signals originated from undissociated species in both CF3COOD (1787 cm-1 and 1766 cm-1 at c0 = 0.1 mol dm-3) and CF3COONa (1807 cm-1 at c0 = 0.1 mol dm-3) D2O solutions, through computational techniques we identified different TFA hydrates that contribute to the complexity of the spectral appearance. The combination of experimental and computational data suggested the concentration dependence of the predominant hydrogen bonding pattern of TFA. The results obtained in this work should help in understanding the partitioning of TFA into micron-size water droplets in the atmosphere in molecular and structural terms, i.e. the eventual stability of a hydrated complex for a particular TFA conformer.
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Affiliation(s)
- Barbara Pem
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| | - Mario Vazdar
- Department of Mathematics, Informatics and Cybernetics, University of Chemistry and Technology, 166 28 Prague, Czech Republic
| | - Danijela Bakarić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
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Persaud D, Criscitiello AS, Spencer C, Lehnherr I, Muir DCG, De Silva AO, Young CJ. A 50 year record for perfluoroalkyl acids in the high arctic: implications for global and local transport. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024. [PMID: 39046203 DOI: 10.1039/d4em00219a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
Perfluoroalkyl acids (PFAAs) are persistent compounds that are ubiquitous globally, though some uncertainties remain in the understanding of their long-range transport mechanisms. They are frequently detected in remote locations, where local sources may be unimportant. We collected a 16.5 metre ice core on northern Ellesmere Island, Nunavut, Canada to investigate PFAA deposition trends and transport mechanisms. The dated core represents fifty years of deposition (1967-2016), which accounts for the longest deposition record of perfluoroalkylcarboxylic acids (PFCAs) in the Arctic and the longest record of perfluoroalkylsulfonic acids (PFSAs) globally. PFCAs were detected frequently after the 1990s and have been increasing since. Homologue pair correlations, molar concentration ratios, and model comparisons suggest that PFCAs are primarily formed through oxidation of volatile precursors. PFSAs showed no discernible trend, with concentrations at least an order of magnitude lower than PFCAs. We observed episodic deposition of some PFAAs, notably perfluorooctane sulfonic acid (PFOS) and perfluorobutane sulfonic acid (PFBS) before the 1990s, which may be linked to Arctic military activities. Tracer analysis suggests that marine aerosols and mineral dust are relevant as transport vectors for selected PFAAs during specific time periods. These observations highlight the complex mechanisms responsible for the transport and deposition of PFAAs in the High Arctic.
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Affiliation(s)
- Daniel Persaud
- Department of Chemistry, York University, Toronto, ON, Canada.
| | - Alison S Criscitiello
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Christine Spencer
- Aquatic Contaminants Research Division, Environmental and Climate Change Canada, Burlington, Ontario, Canada.
| | - Igor Lehnherr
- Department of Geography, Geomatics and Environment, University of Toronto-Mississauga, Mississauga, Ontario, Canada
| | - Derek C G Muir
- Aquatic Contaminants Research Division, Environmental and Climate Change Canada, Burlington, Ontario, Canada.
| | - Amila O De Silva
- Aquatic Contaminants Research Division, Environmental and Climate Change Canada, Burlington, Ontario, Canada.
| | - Cora J Young
- Department of Chemistry, York University, Toronto, ON, Canada.
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Li X, Wang Y, Cui J, Shi Y, Cai Y. Occurrence and Fate of Per- and Polyfluoroalkyl Substances (PFAS) in Atmosphere: Size-Dependent Gas-Particle Partitioning, Precipitation Scavenging, and Amplification. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:9283-9291. [PMID: 38752583 DOI: 10.1021/acs.est.4c00569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
The concerns about the fate of per- and polyfluoroalkyl substances (PFAS) in the atmosphere are continuously growing. In this study, size-fractionated particles, gas, and rainwater samples were simultaneously collected in Shijiazhuang, China, to investigate the multiphase distribution of PFAS in the atmosphere. Perfluoroalkyl carboxylic acids (PFCAs) dominated the total concentration of PFAS in atmospheric media. A strong positive relationship (0.79 < R2 < 0.99) was observed between the concentration of PFCAs and organic matter fraction (fOM) in different particle size fractions, while no such relationship for perfluoroalkyl sulfonic acids (PFSAs) and fOM, suggesting fOM may be an important factor influencing the size-dependent distribution of PFCAs. Temperature played a key role in the gas-particle partitioning of PFAS, while it did not significantly affect their particle-size-dependent distribution. The associative concentration fluctuation of particle and particle-bound PFAS during precipitation suggested that precipitation scavenging was an important mechanism for the removal of PFAS from the atmosphere. Furthermore, temporary increases in atmospheric PFAS concentrations were observed during the precipitation. Fugacity ratios of PFAS in rainwater and gas phase (log fR/fG ranged between 2.0 and 6.6) indicated a strong trend for PFAS to diffuse from the rainwater to the gas phase during the precipitation, which may explain that the concentration of PFAS in the gas phase continued to increase even at the end of the precipitation.
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Affiliation(s)
- Xiaotong Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuan Wang
- College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China
| | - Jiansheng Cui
- College of Environmental Science and Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China
| | - Yali Shi
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaqi Cai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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Ye R, Di Lorenzo RA, Clouthier JT, Young CJ, VandenBoer TC. A Rapid Derivatization for Quantitation of Perfluorinated Carboxylic Acids from Aqueous Matrices by Gas Chromatography-Mass Spectrometry. Anal Chem 2023; 95:7648-7655. [PMID: 37133404 DOI: 10.1021/acs.analchem.3c00593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Ultrashort-chain perfluorinated carboxylic acids (PFCAs) are receiving more attention due to their ever-increasing presence in the environment. Methods have been established for the analysis of short- and long-chain PFCAs, while robust quantitation of ultrashort-chain species is scarce. Here, we develop a novel derivatization method using diphenyl diazomethane for quantitation of C2-C14 PFCAs in aqueous matrices. The method is highlighted by rapid completion of derivatization (<1 min) and retention and separation of ultrashort-chain (C2/C3) PFCA derivatives using H2 carrier gas (R > 1.5). A weak anion exchange solid-phase extraction procedure for analyte recovery from representative aqueous samples was developed and validated by spike and recovery from ultrapure water, synthetic ocean water, and simulated denuder extracts used for collecting gaseous PFCAs. Recoveries for PFCAs ranged from 83 to 130% for the majority of analytes and matrices. The instrument detection limits (IDLs) range from 8 to 220 fg per injection, and method detection limits (MDLs) range from 0.06 to 14.6 pg/mL for 500 mL aqueous samples, which are within an order of magnitude to conventional LC-MS/MS methods. The method was applied to the analysis of real samples of tap water, rainwater, ocean water, and annular denuder extracts. The overall method provides a cost-effective alternative to conventional LC-MS/MS methods, overcoming the typical GC-MS drawbacks of high detection limits and long sample preparation times while being able to simultaneously analyze the complete spectrum of environmentally relevant PFCAs.
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Affiliation(s)
- RenXi Ye
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Robert A Di Lorenzo
- Department of Chemistry, Memorial University, St. John's, Newfoundland and Labrador A1B 3X7, Canada
| | - Jessica T Clouthier
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Cora J Young
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
| | - Trevor C VandenBoer
- Department of Chemistry, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3, Canada
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