1
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Zhong L, Zhu B, Su W, Liang W, Wang H, Li T, Cao D, Ruan T, Chen J, Jiang G. Molecular characterization of diverse quinone analogs for discrimination of aerosol-bound persistent pyrolytic and photolytic radicals. Sci Bull (Beijing) 2024; 69:612-620. [PMID: 38101961 DOI: 10.1016/j.scib.2023.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/02/2023] [Accepted: 11/24/2023] [Indexed: 12/17/2023]
Abstract
Aerosol-bound organic radicals, including environmentally persistent free radicals (EPFRs), are key components that affect climate, air quality, and human health. While putative structures have been proposed, the molecular characteristics of EPFRs remain unknown. Here, we report a surrogate method to characterize EPFRs in real ambient samples using mass spectrometry. The method identifies chemically relevant oxygenated polycyclic aromatic hydrocarbons (OxPAH) that interconvert with oxygen-centered EPFR (OC-EPFR). We found OxPAH compounds most relevant to OC-EPFRs are structurally rich and diverse quinones, whose diversity is strongly associated with OC-EPFR levels. Both atmospheric oxidation and combustion contributed to OC-EPFR formation. Redundancy analysis and photochemical aging model show pyrolytic sources generated more oxidized OC-EPFRs than photolytic sources. Our study reveals the detailed molecular characteristics of OC-EPFRs and shows that oxidation states can be used to identify the origins of OC-EPFRs, offering a way to track the development and evolution of aerosol particles in the environment.
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Affiliation(s)
- Laijin Zhong
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Bao Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Wenyuan Su
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Wenqing Liang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Haotian Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Tingyu Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Dong Cao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ting Ruan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Jianmin Chen
- Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, 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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2
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Khan F, Chen Y, Hartwell HJ, Yan J, Lin YH, Freedman A, Zhang Z, Zhang Y, Lambe AT, Turpin BJ, Gold A, Ault AP, Szmigielski R, Fry RC, Surratt JD. Heterogeneous Oxidation Products of Fine Particulate Isoprene Epoxydiol-Derived Methyltetrol Sulfates Increase Oxidative Stress and Inflammatory Gene Responses in Human Lung Cells. Chem Res Toxicol 2023; 36:1814-1825. [PMID: 37906555 DOI: 10.1021/acs.chemrestox.3c00278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Hydroxyl radical (·OH)-initiated oxidation of isoprene, the most abundant nonmethane hydrocarbon in the atmosphere, is responsible for substantial amounts of secondary organic aerosol (SOA) within ambient fine particles. Fine particulate 2-methyltetrol sulfate diastereoisomers (2-MTSs) are abundant SOA products formed via acid-catalyzed multiphase chemistry of isoprene-derived epoxydiols with inorganic sulfate aerosols under low-nitric oxide conditions. We recently demonstrated that heterogeneous ·OH oxidation of particulate 2-MTSs leads to the particle-phase formation of multifunctional organosulfates (OSs). However, it remains uncertain if atmospheric chemical aging of particulate 2-MTSs induces toxic effects within human lung cells. We show that inhibitory concentration-50 (IC50) values decreased from exposure to fine particulate 2-MTSs that were heterogeneously aged for 0 to 22 days by ·OH, indicating increased particulate toxicity in BEAS-2B lung cells. Lung cells further exhibited concentration-dependent modulation of oxidative stress- and inflammatory-related gene expression. Principal component analysis was carried out on the chemical mixtures and revealed positive correlations between exposure to aged multifunctional OSs and altered expression of targeted genes. Exposure to particulate 2-MTSs alone was associated with an altered expression of antireactive oxygen species (ROS)-related genes (NQO-1, SOD-2, and CAT) indicative of a response to ROS in the cells. Increased aging of particulate 2-MTSs by ·OH exposure was associated with an increased expression of glutathione pathway-related genes (GCLM and GCLC) and an anti-inflammatory gene (IL-10).
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Affiliation(s)
- Faria Khan
- Institute of Physical Chemistry,Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Yuzhi Chen
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Hadley J Hartwell
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jin Yan
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Ying-Hsuan Lin
- Department of Environmental Sciences, University of California, Riverside, California 92521, United States
| | - Anastasia Freedman
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Zhenfa Zhang
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Yue Zhang
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Department of Atmospheric Sciences, Texas A&M University, College Station Texas 77843, United States
| | - Andrew T Lambe
- Aerodyne Research Inc, Billerica, Massachusetts 01821, United States
| | - Barbara J Turpin
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Avram Gold
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Andrew P Ault
- Department of Chemistry, College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Rafal Szmigielski
- Institute of Physical Chemistry,Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Rebecca C Fry
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jason D Surratt
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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3
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Costabile F, Gualtieri M, Rinaldi M, Canepari S, Vecchi R, Massimi L, Di Iulio G, Paglione M, Di Liberto L, Corsini E, Facchini MC, Decesari S. Exposure to urban nanoparticles at low PM[Formula: see text] concentrations as a source of oxidative stress and inflammation. Sci Rep 2023; 13:18616. [PMID: 37903867 PMCID: PMC10616204 DOI: 10.1038/s41598-023-45230-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 10/17/2023] [Indexed: 11/01/2023] Open
Abstract
Exposures to fine particulate matter (PM[Formula: see text]) have been associated with health impacts, but the understanding of the PM[Formula: see text] concentration-response (PM[Formula: see text]-CR) relationships, especially at low PM[Formula: see text], remains incomplete. Here, we present novel data using a methodology to mimic lung exposure to ambient air (2[Formula: see text] 60 [Formula: see text]g m[Formula: see text]), with minimized sampling artifacts for nanoparticles. A reference model (Air Liquid Interface cultures of human bronchial epithelial cells, BEAS-2B) was used for aerosol exposure. Non-linearities observed in PM[Formula: see text]-CR curves are interpreted as a result of the interplay between the aerosol total oxidative potential (OP[Formula: see text]) and its distribution across particle size (d[Formula: see text]). A d[Formula: see text]-dependent condensation sink (CS) is assessed together with the distribution with d[Formula: see text] of reactive species . Urban ambient aerosol high in OP[Formula: see text], as indicated by the DTT assay, with (possibly copper-containing) nanoparticles, shows higher pro-inflammatory and oxidative responses, this occurring at lower PM[Formula: see text] concentrations (< 5 [Formula: see text]g m[Formula: see text]). Among the implications of this work, there are recommendations for global efforts to go toward the refinement of actual air quality standards with metrics considering the distribution of OP[Formula: see text] with d[Formula: see text] also at relatively low PM[Formula: see text].
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Affiliation(s)
- Francesca Costabile
- Institute of Atmospheric Sciences and Climate - Italian National Research Council (ISAC - CNR), Via Fosso del Cavaliere, 00133 Rome, Italy
- National Biodiversity Future Center, NBFC, 90133 Palermo, Italy
| | - Maurizio Gualtieri
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, 26126 Milan, Italy
| | - Matteo Rinaldi
- National Biodiversity Future Center, NBFC, 90133 Palermo, Italy
- Institute of Atmospheric Sciences and Climate - Italian National Research Council (ISAC - CNR), Via Gobetti, 40129 Bologna, Italy
| | - Silvia Canepari
- Department of Environmental Biology, University of Rome Sapienza, 00185 Rome, Italy
| | - Roberta Vecchi
- Department of Physics, Università degli Studi di Milano,and INFN-Milan, 20133 Milan, Italy
| | - Lorenzo Massimi
- Department of Environmental Biology, University of Rome Sapienza, 00185 Rome, Italy
| | - Gianluca Di Iulio
- Institute of Atmospheric Sciences and Climate - Italian National Research Council (ISAC - CNR), Via Fosso del Cavaliere, 00133 Rome, Italy
| | - Marco Paglione
- National Biodiversity Future Center, NBFC, 90133 Palermo, Italy
- Institute of Atmospheric Sciences and Climate - Italian National Research Council (ISAC - CNR), Via Gobetti, 40129 Bologna, Italy
| | - Luca Di Liberto
- Institute of Atmospheric Sciences and Climate - Italian National Research Council (ISAC - CNR), Via Fosso del Cavaliere, 00133 Rome, Italy
| | - Emanuela Corsini
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133 Milan, Italy
| | - Maria Cristina Facchini
- Institute of Atmospheric Sciences and Climate - Italian National Research Council (ISAC - CNR), Via Gobetti, 40129 Bologna, Italy
| | - Stefano Decesari
- National Biodiversity Future Center, NBFC, 90133 Palermo, Italy
- Institute of Atmospheric Sciences and Climate - Italian National Research Council (ISAC - CNR), Via Gobetti, 40129 Bologna, Italy
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4
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Li F, Tang S, Lv J, He A, Wang Y, Liu S, Cao H, Zhao L, Wang Y, Jiang G. Molecular-Scale Investigation on the Formation of Brown Carbon Aerosol via Iron-Phenolic Compound Reactions in the Dark. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:11173-11184. [PMID: 37462533 DOI: 10.1021/acs.est.3c04263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Brown carbon (BrC) is one of the most mysterious aerosol components responsible for global warming and air pollution. Iron (Fe)-induced catalytic oxidation of ubiquitous phenolic compounds has been considered as a potential pathway for BrC formation in the dark. However, the reaction mechanism and product composition are still poorly understood. Herein, 13 phenolic precursors were employed to react with Fe under environmentally relevant conditions. Using Fourier transform ion cyclotron resonance mass spectrometry, a total of 764 unique molecular formulas were identified, and over 85% of them can be found in atmospheric aerosols. In particular, products derived from precursors with catechol-, guaiacol-, and syringol-like-based structures can be distinguished by their optical and molecular characteristics, indicating the structure-dependent formation of BrC from phenolic precursors. Multiple pieces of evidence indicate that under acidic conditions, the contribution of either autoxidation or oxygen-induced free radical oxidation to BrC formation is extremely limited. Ligand-to-Fe charge transfer and subsequent phenoxy radical coupling reactions were the main mechanism for the formation of polymerization products with high molecular diversity, and the efficiency of BrC generation was linearly correlated with the ionization potential of phenolic precursors. The present study uncovered how chemically diverse BrC products were formed by the Fe-phenolic compound reactions at the molecular level and also provide a new paradigm for the study of the atmospheric aerosol formation mechanism.
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Affiliation(s)
- Feifei Li
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shanshan Tang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Jitao Lv
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Anen He
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yarui Wang
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuting Liu
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huiming Cao
- Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan 430056, China
| | - Lixia Zhao
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Yawei Wang
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
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5
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De Haan DO, Hawkins LN, Wickremasinghe PD, Andretta AD, Dignum JR, De Haan AC, Welsh HG, Pennington EA, Cui T, Surratt JD, Cazaunau M, Pangui E, Doussin JF. Brown Carbon from Photo-Oxidation of Glyoxal and SO 2 in Aqueous Aerosol. ACS EARTH & SPACE CHEMISTRY 2023; 7:1131-1140. [PMID: 37223425 PMCID: PMC10201569 DOI: 10.1021/acsearthspacechem.3c00035] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 05/25/2023]
Abstract
Aqueous-phase dark reactions during the co-oxidation of glyoxal and S(IV) were recently identified as a potential source of brown carbon (BrC). Here, we explore the effects of sunlight and oxidants on aqueous solutions of glyoxal and S(IV), and on aqueous aerosol exposed to glyoxal and SO2. We find that BrC is able to form in sunlit, bulk-phase, sulfite-containing solutions, albeit more slowly than in the dark. In more atmospherically relevant chamber experiments where suspended aqueous aerosol particles are exposed to gas-phase glyoxal and SO2, the formation of detectable amounts of BrC requires an OH radical source and occurs most rapidly after a cloud event. From these observations we infer that this photobrowning is caused by radical-initiated reactions as evaporation concentrates aqueous-phase reactants and aerosol viscosity increases. Positive-mode electrospray ionization mass spectrometric analysis of aerosol-phase products reveals a large number of CxHyOz oligomers that are reduced rather than oxidized (relative to glyoxal), with the degree of reduction increasing in the presence of OH radicals. This again suggests a radical-initiated redox mechanism where photolytically produced aqueous radical species trigger S(IV)-O2 auto-oxidation chain reactions, and glyoxal-S(IV) redox reactions especially if aerosol-phase O2 is depleted. This process may contribute to daytime BrC production and aqueous-phase sulfur oxidation in the atmosphere. The BrC produced, however, is about an order of magnitude less light-absorbing than wood smoke BrC at 365 nm.
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Affiliation(s)
- David O. De Haan
- Department
of Chemistry and Biochemistry, University
of San Diego, 5998 Alcala Park, San Diego, California 92117, United States
| | - Lelia N. Hawkins
- Department
of Chemistry, Harvey Mudd College, 301 Platt Blvd, Claremont, California 91711, United States
| | - Praveen D. Wickremasinghe
- Department
of Chemistry and Biochemistry, University
of San Diego, 5998 Alcala Park, San Diego, California 92117, United States
| | - Alyssa D. Andretta
- Department
of Chemistry and Biochemistry, University
of San Diego, 5998 Alcala Park, San Diego, California 92117, United States
| | - Juliette R. Dignum
- Department
of Chemistry and Biochemistry, University
of San Diego, 5998 Alcala Park, San Diego, California 92117, United States
| | - Audrey C. De Haan
- Department
of Chemistry and Biochemistry, University
of San Diego, 5998 Alcala Park, San Diego, California 92117, United States
| | - Hannah G. Welsh
- Department
of Chemistry, Harvey Mudd College, 301 Platt Blvd, Claremont, California 91711, United States
| | - Elyse A. Pennington
- Department
of Chemistry, Harvey Mudd College, 301 Platt Blvd, Claremont, California 91711, United States
| | - Tianqu Cui
- Department
of Environmental Sciences and Engineering, Gillings School of Global
Public Health, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina 27599, United States
| | - Jason D. Surratt
- Department
of Environmental Sciences and Engineering, Gillings School of Global
Public Health, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina 27599, United States
- Department
of Chemistry, College of Arts and Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Mathieu Cazaunau
- Laboratoire
Interuniversitaire des Systèmes Atmosphériques (LISA),
UMR7583, CNRS, Institut Pierre Simon Laplace (IPSL), Université Paris-Est-Créteil (UPEC) et Université
Paris Diderot (UPD), Créteil 94010, France
| | - Edouard Pangui
- Laboratoire
Interuniversitaire des Systèmes Atmosphériques (LISA),
UMR7583, CNRS, Institut Pierre Simon Laplace (IPSL), Université Paris-Est-Créteil (UPEC) et Université
Paris Diderot (UPD), Créteil 94010, France
| | - Jean-François Doussin
- Laboratoire
Interuniversitaire des Systèmes Atmosphériques (LISA),
UMR7583, CNRS, Institut Pierre Simon Laplace (IPSL), Université Paris-Est-Créteil (UPEC) et Université
Paris Diderot (UPD), Créteil 94010, France
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6
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Smith N, Crescenzo GV, Bertram AK, Nizkorodov SA, Faiola CL. Insect Infestation Increases Viscosity of Biogenic Secondary Organic Aerosol. ACS EARTH & SPACE CHEMISTRY 2023; 7:1060-1071. [PMID: 37223424 PMCID: PMC10201571 DOI: 10.1021/acsearthspacechem.3c00007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/20/2023] [Accepted: 04/13/2023] [Indexed: 05/25/2023]
Abstract
Plant stress alters emissions of volatile organic compounds. However, little is known about how this could influence climate-relevant properties of secondary organic aerosol (SOA), particularly from complex mixtures such as real plant emissions. In this study, the chemical composition and viscosity were examined for SOA generated from real healthy and aphid-stressed Canary Island pine (Pinus canariensis) trees, which are commonly used for landscaping in Southern California. Healthy Canary Island pine (HCIP) and stressed Canary Island pine (SCIP) aerosols were generated in a 5 m3 environmental chamber at 35-84% relative humidity and room temperature via OH-initiated oxidation. Viscosities of the collected particles were measured using an offline poke-flow method, after conditioning the particles in a humidified air flow. SCIP particles were consistently more viscous than HCIP particles. The largest differences in particle viscosity were observed in particles conditioned at 50% relative humidity where the viscosity of SCIP particles was an order of magnitude larger than that of HCIP particles. The increased viscosity for the aphid-stressed pine tree SOA was attributed to the increased fraction of sesquiterpenes in the emission profile. The real pine SOA particles, both healthy and aphid-stressed, were more viscous than α-pinene SOA particles, demonstrating the limitation of using a single monoterpene as a model compound to predict the physicochemical properties of real biogenic SOA. However, synthetic mixtures composed of only a few major compounds present in emissions (<10 compounds) can reproduce the viscosities of SOA observed from the more complex real plant emissions.
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Affiliation(s)
- Natalie
R. Smith
- Department
of Chemistry, University of California,
Irvine, Irvine, California 92697, United States
| | - Giuseppe V. Crescenzo
- Department
of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Allan K. Bertram
- Department
of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Sergey A. Nizkorodov
- Department
of Chemistry, University of California,
Irvine, Irvine, California 92697, United States
| | - Celia L. Faiola
- Department
of Chemistry, University of California,
Irvine, Irvine, California 92697, United States
- Department
of Ecology and Evolutionary Biology, University
of California, Irvine, Irvine, California 92697, United States
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7
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Wang J, Huang D, Chen F, Chen J, Jiang H, Zhu Y, Chen C, Zhao J. Rapid Redox Cycling of Fe(II)/Fe(III) in Microdroplets during Iron-Citric Acid Photochemistry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:4434-4442. [PMID: 36883325 DOI: 10.1021/acs.est.2c07897] [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: 06/18/2023]
Abstract
Fe(III) and carboxylic acids are common compositions in atmospheric microdroplet systems like clouds, fogs, and aerosols. Although photochemical processes of Fe(III)-carboxylate complexes have been extensively studied in bulk aqueous solution, relevant information on the dynamic microdroplet system, which may be largely different from the bulk phase, is rare. With the help of the custom-made ultrasonic-based dynamic microdroplet photochemical system, this study examines the photochemical process of Fe(III)-citric acid complexes in microdroplets for the first time. We find that when the degradation extent of citric acid is similar between the microdroplet system and the bulk solution, the significantly lower Fe(II) ratio is present in microdroplet samples due to the rapider reoxidation of photogenerated Fe(II). However, by replacing citric acid with benzoic acid, no much difference in the Fe(II) ratio between microdroplets and bulk solution is observed, which indicates distinct reoxidation pathways of Fe(II). Moreover, the presence of •OH scavenger, namely, methanol, greatly accelerates the reoxidation of photogenerated Fe(II) in both citric acid and benzoic acid situations. Further experiments reveal that the high availability of O2 and the citric acid- or methanol-derived carbon-centered radicals are responsible for the rapider reoxidation of Fe(II) in iron-citric acid microdroplets by prolonging the length of HO2•- and H2O2-involved radical reaction chains. The results in this study may provide a new understanding about iron-citric acid photochemistry in atmospheric liquid particles, which can further influence the photoactivity of particles and the formation of secondary organic aerosols.
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Affiliation(s)
- Jinzhao Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Di Huang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Fengxia Chen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jianhua Chen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Hongyu Jiang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yifan Zhu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Chuncheng Chen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jincai Zhao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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8
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West CP, Morales AC, Ryan J, Misovich MV, Hettiyadura APS, Rivera-Adorno F, Tomlin JM, Darmody A, Linn BN, Lin P, Laskin A. Molecular investigation of the multi-phase photochemistry of Fe(III)-citrate in aqueous solution. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:190-213. [PMID: 35634912 DOI: 10.1039/d1em00503k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Iron (Fe) is ubiquitous in nature and found as FeII or FeIII in minerals or as dissolved ions Fe2+ or Fe3+ in aqueous systems. The interactions of soluble Fe have important implications for fresh water and marine biogeochemical cycles, which have impacts on global terrestrial and atmospheric environments. Upon dissolution of FeIII into natural aquatic systems, organic carboxylic acids efficiently chelate FeIII to form [FeIII-carboxylate]2+ complexes that undergo a wide range of photochemistry-induced radical reactions. The chemical composition and photochemical transformations of these mixtures are largely unknown, making it challenging to estimate their environmental impact. To investigate the photochemical process of FeIII-carboxylates at the molecular level, we conduct a comprehensive experimental study employing UV-visible spectroscopy, liquid chromatography coupled to photodiode array and high-resolution mass spectrometry detection, and oil immersion flow microscopy. In this study, aqueous solutions of FeIII-citrate were photolyzed under 365 nm light in an experimental setup with an apparent quantum yield of (φ) ∼0.02, followed by chemical analyses of reacted mixtures withdrawn at increment time intervals of the experiment. The apparent photochemical reaction kinetics of Fe3+-citrates (aq) were expressed as two generalized consecutive reactions of with the experimental rate constants of j1 ∼ 0.12 min-1 and j2 ∼ 0.05 min-1, respectively. Molecular characterization results indicate that R and I consist of both water-soluble organic and Fe-organic species, while P compounds are a mixture of water-soluble and colloidal materials. The latter were identified as Fe-carbonaceous colloids formed at long photolysis times. The carbonaceous content of these colloids was identified as unsaturated organic species with low oxygen content and carbon with a reduced oxidation state, indicative of their plausible radical recombination mechanism under oxygen-deprived conditions typical for the extensively photolyzed mixtures. Based on the molecular characterization results, we discuss the comprehensive reaction mechanism of FeIII-citrate photochemistry and report on the formation of previously unexplored colloidal reaction products, which may contribute to atmospheric and terrestrial light-absorbing materials in aquatic environments.
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Affiliation(s)
- Christopher P West
- Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA.
| | - Ana C Morales
- Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA.
| | - Jackson Ryan
- Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA.
| | - Maria V Misovich
- Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA.
| | | | | | - Jay M Tomlin
- Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA.
| | - Andrew Darmody
- Department of Aeronautics and Aerospace Engineering, Purdue University, West Lafayette, IN, USA
| | - Brittany N Linn
- Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA.
| | - Peng Lin
- Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA.
| | - Alexander Laskin
- Department of Chemistry, Purdue University, West Lafayette, IN, 47906, USA.
- Department of Earth, Atmospheric & Planetary Sciences, Purdue University, West Lafayette, IN, USA
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9
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Wang S, Zhao Y, Chan AWH, Yao M, Chen Z, Abbatt JPD. Organic Peroxides in Aerosol: Key Reactive Intermediates for Multiphase Processes in the Atmosphere. Chem Rev 2023; 123:1635-1679. [PMID: 36630720 DOI: 10.1021/acs.chemrev.2c00430] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Organic peroxides (POs) are organic molecules with one or more peroxide (-O-O-) functional groups. POs are commonly regarded as chemically labile termination products from gas-phase radical chemistry and therefore serve as temporary reservoirs for oxidative radicals (HOx and ROx) in the atmosphere. Owing to their ubiquity, active gas-particle partitioning behavior, and reactivity, POs are key reactive intermediates in atmospheric multiphase processes determining the life cycle (formation, growth, and aging), climate, and health impacts of aerosol. However, there remain substantial gaps in the origin, molecular diversity, and fate of POs due to their complex nature and dynamic behavior. Here, we summarize the current understanding on atmospheric POs, with a focus on their identification and quantification, state-of-the-art analytical developments, molecular-level formation mechanisms, multiphase chemical transformation pathways, as well as environmental and health impacts. We find that interactions with SO2 and transition metal ions are generally the fast PO transformation pathways in atmospheric liquid water, with lifetimes estimated to be minutes to hours, while hydrolysis is particularly important for α-substituted hydroperoxides. Meanwhile, photolysis and thermolysis are likely minor sinks for POs. These multiphase PO transformation pathways are distinctly different from their gas-phase fates, such as photolysis and reaction with OH radicals, which highlights the need to understand the multiphase partitioning of POs. By summarizing the current advances and remaining challenges for the investigation of POs, we propose future research priorities regarding their origin, fate, and impacts in the atmosphere.
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Affiliation(s)
- Shunyao Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai200240, China
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai200444, China
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, OntarioM5S 3E5, Canada
| | - Yue Zhao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, OntarioM5S 3E5, Canada
- School of the Environment, University of Toronto, Toronto, OntarioM5S 3E8, Canada
| | - Min Yao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Zhongming Chen
- State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing100871, China
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, Toronto, OntarioM5S 3H6, Canada
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10
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Wang S, Gallimore PJ, Liu-Kang C, Yeung K, Campbell SJ, Utinger B, Liu T, Peng H, Kalberer M, Chan AWH, Abbatt JPD. Dynamic Wood Smoke Aerosol Toxicity during Oxidative Atmospheric Aging. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:1246-1256. [PMID: 36630690 DOI: 10.1021/acs.est.2c05929] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Wildfires are a major source of biomass burning aerosol to the atmosphere, with their incidence and intensity expected to increase in a warmer future climate. However, the toxicity evolution of biomass burning organic aerosol (BBOA) during atmospheric aging remains poorly understood. In this study, we report a unique set of chemical and toxicological metrics of BBOA from pine wood smoldering during multiphase aging by gas-phase hydroxyl radicals (OH). Both the fresh and OH-aged BBOA show activity relevant to adverse health outcomes. The results from two acellular assays (DTT and DCFH) show significant oxidative potential (OP) and reactive oxygen species (ROS) formation in OH-aged BBOA. Also, radical concentrations in the aerosol assessed by electron paramagnetic resonance (EPR) spectroscopy increased by 50% following heterogeneous aging. This enhancement was accompanied by a transition from predominantly carbon-centered radicals (85%) in the fresh aerosol to predominantly oxygen-centered radicals (76%) following aging. Both the fresh and aged biomass burning aerosols trigger prominent antioxidant defense during the in vitro exposure, indicating the induction of oxidative stress by BBOA in the atmosphere. By connecting chemical composition and toxicity using an integrated approach, we show that short-term aging initiated by OH radicals can produce biomass burning particles with a higher particle-bound ROS generation capacity, which are therefore a more relevant exposure hazard for residents in large population centers close to wildfire regions than previously studied fresh biomass burning emissions.
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Affiliation(s)
- Shunyao Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Peter J Gallimore
- Department of Earth and Environmental Sciences, University of Manchester, Manchester M13 9PL, United Kingdom
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Carolyn Liu-Kang
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Kirsten Yeung
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
| | - Steven J Campbell
- Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
- Department of Environmental Sciences, University of Basel, 4056 Basel, Switzerland
| | - Battist Utinger
- Department of Environmental Sciences, University of Basel, 4056 Basel, Switzerland
| | - Tengyu Liu
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
| | - Hui Peng
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- School of the Environment, University of Toronto, Toronto, Ontario M5S 3E8, Canada
| | - Markus Kalberer
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Arthur W H Chan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
- School of the Environment, University of Toronto, Toronto, Ontario M5S 3E8, Canada
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
- School of the Environment, University of Toronto, Toronto, Ontario M5S 3E8, Canada
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11
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Ammann M, Artiglia L. Solvation, Surface Propensity, and Chemical Reactions of Solutes at Atmospheric Liquid-Vapor Interfaces. Acc Chem Res 2022; 55:3641-3651. [PMID: 36472357 PMCID: PMC9774673 DOI: 10.1021/acs.accounts.2c00604] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Indexed: 12/12/2022]
Abstract
surface is covered by oceans, a large number of liquid aerosol particles fill the air, and clouds hold a tiny but critical fraction of Earth's water in the air to influence our climate and hydrology, enabling the lives of humans and ecosystems. The surfaces of these liquids provide the interface for the transfer of gases, for nucleation processes, and for catalyzing important chemical reactions. Coupling a range of spectroscopic tools to liquid microjets has become an important approach to better understanding dynamics, structure, and chemistry at liquid interfaces. Liquid microjets offer stability in vacuum and ambient pressure environments, thus also allowing X-ray photoelectron spectroscopy (XPS) with manageable efforts in terms of differential pumping. Liquid microjets are operated at speeds sufficient to allow for a locally equilibrated surface in terms of water dynamics and solute surface partitioning. XPS is based on the emission of core-level electrons, the binding energy of which is selective for the element and its chemical environment. Inelastic scattering of electrons establishes the probing depth of XPS in the nanometer range and thus its surface sensitivity.In this Account, we focus on aqueous solutions relevant to the surface of oceans, aqueous aerosols, or cloudwater. We are interested in understanding solvation and acid dissociation at the interface, interfacial aspects of reactions with gas-phase reactants, and the interplay of ions with organic molecules at the interface. The strategy is to obtain a link between the molecular-level picture and macroscopic properties and reactivity in the atmospheric context.We show consistency between surface tension and XPS for a range of surface-active organic species as an important proof for interrogating an equilibrated liquid surface. Measurements with organic acids and amines offer important insight into the question of apparent acidity or basicity at the interface. Liquid microjet XPS has settled the debate of the surface enhancement of halide ions, shown using the example of bromide and its oxidation products. Despite the absence of a strong enhancement for the bromide ion, its rate of oxidation by ozone is surface catalyzed through the stabilization of the bromide ozonide intermediate at the interface. In another reaction system, the one between Fe2+ and H2O2, a similar intermediate in the form of highly valent iron species could not be detected by XPS under the experimental conditions employed, shedding light on the abundance of this intermediate in the environment but also on the constraints within which surface species can be detected. Emphasizing the importance of electrostatic effects, we show how a cationic surfactant attracts charged bromide anions to the interface, accompanied by enhanced oxidation rates by ozone, overriding the role of surfactants as a barrier for the access of gas-phase reactants. The reactivity and structure at interfaces thus result from a subtle balance between hygroscopic and hydrophobic interactions, electrostatic effects, and the structural properties of both liquids and solutes.
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Affiliation(s)
- Markus Ammann
- Laboratory of Environmental
Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Luca Artiglia
- Laboratory of Environmental
Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
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12
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Rashid MH, Borca CN, Xto JM, Huthwelker T. X-Ray absorption spectroscopy on airborne aerosols. ENVIRONMENTAL SCIENCE: ATMOSPHERES 2022; 2:1338-1350. [PMID: 36561554 PMCID: PMC9648630 DOI: 10.1039/d2ea00016d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 09/26/2022] [Indexed: 11/07/2022]
Abstract
Here we demonstrate a method for performing X-ray absorption spectroscopy (XAS) on airborne aerosols. XAS provides unique insight into elemental composition, chemical and phase state, local coordination and electronic structure of both crystalline and amorphous matter. The aerosol is generated from different salt solutions using a commercial atomizer and dried using a diffusion drier. Embedded in a carrier gas, the aerosol is guided into the experimental chamber for XAS analysis. Typical particle sizes range from some 10 to a few 100 nm. Inside the chamber the aerosol bearing gas is then confined into a region of about 1-2 cm3 in size, by a pure flow of helium, generating a stable free-flowing stream of aerosol. It is hit by a monochromatic X-ray beam, and the emitted fluorescent light is used for spectroscopic analysis. Using an aerosol generated from CaCl2, KCl, and (NH4)2SO4 salt solutions, we demonstrate the functionality of the system in studying environmentally relevant systems. In addition, we show that the detection limits are sufficient to also observe subtle spectroscopic signatures in XAS spectra with integration times of about 1-2 hours using a bright undulator beamline. This novel setup opens new research opportunities for studying the nucleation of new phases in multicomponent aerosol systems in situ, and for investigating (photo-) chemical reactions on airborne matter, as relevant to both atmospheric science and also for general chemical application.
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Affiliation(s)
- Muhammad H. Rashid
- Paul Scherrer Institute, Swiss Light Source, Laboratory for FemtochemistryForschungsstrasse 111Villigen PSISwitzerland
| | - Camelia N. Borca
- Paul Scherrer Institute, Swiss Light Source, Laboratory for FemtochemistryForschungsstrasse 111Villigen PSISwitzerland
| | - Jacinta M. Xto
- Paul Scherrer Institute, Swiss Light Source, Laboratory for FemtochemistryForschungsstrasse 111Villigen PSISwitzerland
| | - Thomas Huthwelker
- Paul Scherrer Institute, Swiss Light Source, Laboratory for FemtochemistryForschungsstrasse 111Villigen PSISwitzerland
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13
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Sunlight can convert atmospheric aerosols into a glassy solid state and modify their environmental impacts. Proc Natl Acad Sci U S A 2022; 119:e2208121119. [PMID: 36269861 PMCID: PMC9618061 DOI: 10.1073/pnas.2208121119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Secondary organic aerosol is well known to affect Earth's climate, regional weather, visibility, and public health. Once these aerosols are formed, they are transported throughout the atmosphere for days or even weeks. We show that exposure of secondary organic aerosols to UV solar radiation leads to a surprising and remarkable increase in viscosity by as much as five orders of magnitude. We also show that this UV exposure can lead to an increased abundance of aerosols that are in the glassy solid state in the troposphere, with important implications for climate predictions. Overall, our results clearly demonstrate that aging by exposure to solar radiation needs to be considered when predicting the environmental impacts of secondary organic aerosols. Secondary organic aerosol (SOA) plays a critical, yet uncertain, role in air quality and climate. Once formed, SOA is transported throughout the atmosphere and is exposed to solar UV light. Information on the viscosity of SOA, and how it may change with solar UV exposure, is needed to accurately predict air quality and climate. However, the effect of solar UV radiation on the viscosity of SOA and the associated implications for air quality and climate predictions is largely unknown. Here, we report the viscosity of SOA after exposure to UV radiation, equivalent to a UV exposure of 6 to 14 d at midlatitudes in summer. Surprisingly, UV-aging led to as much as five orders of magnitude increase in viscosity compared to unirradiated SOA. This increase in viscosity can be rationalized in part by an increase in molecular mass and oxidation of organic molecules constituting the SOA material, as determined by high-resolution mass spectrometry. We demonstrate that UV-aging can lead to an increased abundance of aerosols in the atmosphere in a glassy solid state. Therefore, UV-aging could represent an unrecognized source of nuclei for ice clouds in the atmosphere, with important implications for Earth’s energy budget. We also show that UV-aging increases the mixing times within SOA particles by up to five orders of magnitude throughout the troposphere with important implications for predicting the growth, evaporation, and size distribution of SOA, and hence, air pollution and climate.
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14
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Alpert PA, Boucly A, Yang S, Yang H, Kilchhofer K, Luo Z, Padeste C, Finizio S, Ammann M, Watts B. Ice nucleation imaged with X-ray spectro-microscopy. ENVIRONMENTAL SCIENCE: ATMOSPHERES 2022; 2:335-351. [PMID: 35694137 PMCID: PMC9119033 DOI: 10.1039/d1ea00077b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 02/07/2022] [Indexed: 11/21/2022]
Abstract
Ice nucleation is one of the most uncertain microphysical processes, as it occurs in various ways and on many types of particles. To overcome this challenge, we present a heterogeneous ice nucleation study on deposition ice nucleation and immersion freezing in a novel cryogenic X-ray experiment with the capability to spectroscopically probe individual ice nucleating and non-ice nucleating particles. Mineral dust type particles composed of either ferrihydrite or feldspar were used and mixed with organic matter of either citric acid or xanthan gum. We observed in situ ice nucleation using scanning transmission X-ray microscopy (STXM) and identified unique organic carbon functionalities and iron oxidation state using near-edge X-ray absorption fine structure (NEXAFS) spectroscopy in the new in situ environmental ice cell, termed the ice nucleation X-ray cell (INXCell). Deposition ice nucleation of ferrihydrite occurred at a relative humidity with respect to ice, RH i, between ∼120-138% and temperatures, T ∼ 232 K. However, we also observed water uptake on ferrihydrite at the same T when deposition ice nucleation did not occur. Although, immersion freezing of ferrihydrite both in pure water droplets and in aqueous citric acid occurred at or slightly below conditions for homogeneous freezing, i.e. the effect of ferrihydrite particles acting as a heterogeneous ice nucleus for immersion freezing was small. Microcline K-rich feldspar mixed with xanthan gum was also used in INXCell experiments. Deposition ice nucleation occurred at conditions when xanthan gum was expected to be highly viscous (glassy). At less viscous conditions, immersion freezing was observed. We extended a model for heterogeneous and homogeneous ice nucleation, named the stochastic freezing model (SFM). It was used to quantify heterogeneous ice nucleation rate coefficients, mimic the competition between homogeneous ice nucleation; water uptake; deposition ice nucleation and immersion freezing, and predict the T and RH i at which ice was observed. The importance of ferrihydrite to act as a heterogeneous ice nucleating particle in the atmosphere using the SFM is discussed.
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Affiliation(s)
- Peter A Alpert
- Laboratory of Environmental Chemistry, Paul Scherrer Institute 5232 Villigen PSI Switzerland
| | - Anthony Boucly
- Laboratory of Environmental Chemistry, Paul Scherrer Institute 5232 Villigen PSI Switzerland
- Electrochemistry Laboratory, Paul Scherrer Institute 5232 Villigen PSI Switzerland
| | - Shuo Yang
- Laboratory of Environmental Chemistry, Paul Scherrer Institute 5232 Villigen PSI Switzerland
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Tsinghua University Beijing 100084 China
| | - Huanyu Yang
- Laboratory of Environmental Chemistry, Paul Scherrer Institute 5232 Villigen PSI Switzerland
| | - Kevin Kilchhofer
- Laboratory of Environmental Chemistry, Paul Scherrer Institute 5232 Villigen PSI Switzerland
| | - Zhaochu Luo
- Laboratory for Multiscale Materials Experiments, Paul Scherrer Institute 5232 Villigen PSI Switzerland
- Laboratory for Mesoscopic Systems, Department of Materials, ETH Zürich Zürich Switzerland
| | - Celestino Padeste
- Laboratory of Nanoscale Biology, Paul Scherrer Institute 5232 Villigen PSI Switzerland
| | - Simone Finizio
- Swiss Light Source, Paul Scherrer Institute 5232 Villigen PSI Switzerland
| | - Markus Ammann
- Laboratory of Environmental Chemistry, Paul Scherrer Institute 5232 Villigen PSI Switzerland
| | - Benjamin Watts
- Swiss Light Source, Paul Scherrer Institute 5232 Villigen PSI Switzerland
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15
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Tong YK, Liu Y, Meng X, Wang J, Zhao D, Wu Z, Ye A. The relative humidity-dependent viscosity of single quasi aerosol particles and possible implications for atmospheric aerosol chemistry. Phys Chem Chem Phys 2022; 24:10514-10523. [PMID: 35441631 DOI: 10.1039/d2cp00740a] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Viscosity is a fundamental physicochemical property of aerosol particles that influences chemical evolution, mass transfer rates, particle formation, etc. and also changes with ambient relative humidity (RH). However, the viscosity of real individual aerosol particles still remains less understood. Here, we developed a novel optical system based on dual optical tweezers to measure the viscosity of single suspending aerosol droplets under different RH conditions. In our experiment, a pair of quasi atmospheric aerosol droplets composed of organic and inorganic chemical substances were trapped and levitated by dual laser beams, respectively, and then collided and coalesced. The backscattering light signals and bright-field images of the dynamic coalescence process were recorded to infer the morphological relaxation time and the diameter of the composited droplet. Then, the viscosity of the droplet was calculated based on these measured values. The ambient RH of the aerosol droplets was controlled by varying the relative flow rates of dry and humidified nitrogen gas in a self-developed aerosol chamber. The viscosities of single aqueous droplets nebulized with solutes of sucrose, various sulfates and nitrates, and organic/inorganic mixtures were measured over the atmospheric RH range. Besides, the viscosities of the proxies of actual ambient aerosols in Beijing were investigated, which reasonably interpreted the aerosol chemistry transforming from sulfate dominating to nitrate dominating at the PM10 (particulate matter with an aerodynamic diameter of less than 10 μm) level in the last decade in Beijing. Furthermore, the hygroscopicity of droplets with a solute of organic/inorganic mixtures was researched to obtain a deep insight into the relationship between the viscosity and mass transfer process. Hence, we provide a robust approach for investigating the viscosity and hygroscopicity of the actual individual liquid PM10 aerosols.
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Affiliation(s)
- Yu-Kai Tong
- Key Laboratory for the Physics and Chemistry of Nanodevices, School of Electronics, Peking University, Beijing 100871, China.
| | - Yaoyao Liu
- Key Laboratory for the Physics and Chemistry of Nanodevices, School of Electronics, Peking University, Beijing 100871, China.
| | - Xiangxinyue Meng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Jie Wang
- Key Laboratory for the Physics and Chemistry of Nanodevices, School of Electronics, Peking University, Beijing 100871, China.
| | - Dongping Zhao
- Key Laboratory for the Physics and Chemistry of Nanodevices, School of Electronics, Peking University, Beijing 100871, China.
| | - Zhijun Wu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Anpei Ye
- Key Laboratory for the Physics and Chemistry of Nanodevices, School of Electronics, Peking University, Beijing 100871, China.
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16
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Corral Arroyo P, David G, Alpert PA, Parmentier EA, Ammann M, Signorell R. Amplification of light within aerosol particles accelerates in-particle photochemistry. Science 2022; 376:293-296. [PMID: 35420964 DOI: 10.1126/science.abm7915] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Optical confinement (OC) structures the optical field and amplifies light intensity inside atmospheric aerosol particles, with major consequences for sunlight-driven aerosol chemistry. Although theorized, the OC-induced spatial structuring has so far defied experimental observation. Here, x-ray spectromicroscopic imaging complemented by modeling provides direct evidence for OC-induced patterning inside photoactive particles. Single iron(III)-citrate particles were probed using the iron oxidation state as a photochemical marker. Based on these results, we predict an overall acceleration of photochemical reactions by a factor of two to three for most classes of atmospheric aerosol particles. Rotation of free aerosol particles and intraparticle molecular transport generally accelerate the photochemistry. Given the prevalence of OC effects, their influence on aerosol particle photochemistry should be considered by atmospheric models.
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Affiliation(s)
- Pablo Corral Arroyo
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Grégory David
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Peter A Alpert
- Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Evelyne A Parmentier
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Markus Ammann
- Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Ruth Signorell
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
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17
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Gladich I, Chen S, Yang H, Boucly A, Winter B, van Bokhoven JA, Ammann M, Artiglia L. Liquid-Gas Interface of Iron Aqueous Solutions and Fenton Reagents. J Phys Chem Lett 2022; 13:2994-3001. [PMID: 35344351 DOI: 10.1021/acs.jpclett.2c00380] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Fenton chemistry, involving the reaction between Fe2+ and hydrogen peroxide, is well-known due to its applications in the mineralization of extremely stable molecules. Different mechanisms, influenced by the reaction conditions and the solvation sphere of iron ions, influence the fate of such reactions. Despite the huge amount of effort spent investigating such processes, a complete understanding is still lacking. This work combines photoelectron spectroscopy and theoretical calculations to investigate the solvation and reactivity of Fe2+ and Fe3+ ions in aqueous solutions. The reaction with hydrogen peroxide, both in homogeneous Fenton reagents and at the liquid-vapor interface, illustrates that both ions are homogeneously distributed in solutions and exhibit an asymmetric octahedral coordination to water in the case of Fe2+. No indications of differences in the reaction mechanism between the liquid-vapor interface and the bulk of the solutions have been found, suggesting that Fe3+ and hydroxyl radicals are the only intermediates.
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Affiliation(s)
- Ivan Gladich
- European Centre for Living Technology (ECLT), Dorsoduro, Calle Crosera, 30123 Venice, Italy
| | - Shuzhen Chen
- Laboratory of Environmental Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
- Institute of Atmospheric and Climate Sciences, ETH Zürich, 8092 Zürich, Switzerland
| | - Huanyu Yang
- Laboratory of Environmental Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
- Institute of Atmospheric and Climate Sciences, ETH Zürich, 8092 Zürich, Switzerland
| | - Anthony Boucly
- Laboratory of Environmental Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Bernd Winter
- Molecular Physics Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Jeroen A van Bokhoven
- Laboratory for Catalysis and Sustainable Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
- Institute for Chemical and Bioengineering, ETH Zürich, 8092 Zürich, Switzerland
| | - Markus Ammann
- Laboratory of Environmental Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
- Institute of Atmospheric and Climate Sciences, ETH Zürich, 8092 Zürich, Switzerland
| | - Luca Artiglia
- Laboratory of Environmental Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
- Laboratory for Catalysis and Sustainable Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
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Martinez-Boubeta C, Simeonidis K. Airborne magnetic nanoparticles may contribute to COVID-19 outbreak: Relationships in Greece and Iran. ENVIRONMENTAL RESEARCH 2022; 204:112054. [PMID: 34547249 PMCID: PMC8450134 DOI: 10.1016/j.envres.2021.112054] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 09/09/2021] [Accepted: 09/09/2021] [Indexed: 05/22/2023]
Abstract
This work attempts to shed light on whether the COVID-19 pandemic rides on airborne pollution. In particular, a two-city study provides evidence that PM2.5 contributes to the timing and severity of the epidemic, without adjustment for confounders. The publicly available data of deaths between March and October 2020, updated it on May 30, 2021, and the average seasonal concentrations of PM2.5 pollution over the previous years in Thessaloniki, the second-largest city of Greece, were investigated. It was found that changes in coronavirus-related deaths follow changes in air pollution and that the correlation between the two data sets is maximized at the lag time of one month. Similar data from Tehran were gathered for comparison. The results of this study underscore that it is possible, if not likely, that pollution nanoparticles are related to COVID-19 fatalities (Granger causality, p < 0.05), contributing to the understanding of the environmental impact on pandemics.
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Affiliation(s)
- C Martinez-Boubeta
- Ecoresources P.C, Giannitson-Santaroza Str. 15-17, 54627, Thessaloniki, Greece.
| | - K Simeonidis
- Ecoresources P.C, Giannitson-Santaroza Str. 15-17, 54627, Thessaloniki, Greece; Department of Physics, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
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19
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Zhang D, Ren H, Hu W, Wu L, Ren L, Deng J, Zhang Q, Sun Y, Wang Z, Kawamura K, Fu P. Latitudinal difference in the molecular distributions of lipid compounds in the forest atmosphere in China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 294:118578. [PMID: 34843855 DOI: 10.1016/j.envpol.2021.118578] [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: 10/18/2021] [Revised: 11/17/2021] [Accepted: 11/24/2021] [Indexed: 06/13/2023]
Abstract
Lipids are important biogenic markers to indicate the sources and chemical process of aerosol particles in the atmosphere. To better understand the influences of biogenic and anthropogenic sources on forest aerosols, total suspended particles (TSP) were collected at Mt. Changbai, Shennongjia, and Xishuangbanna that are located at different climatic zones in northeastern, central and southwestern China. n-Alkanes, fatty acids and n-alcohols were detected in the forest aerosols based on gas chromatography-mass spectrometry. The total concentrations of aliphatic compounds ranged from 15.3 ng m-3 to 566 ng m-3, and fatty acids were the most abundant (44-95%) followed by n-alkanes and n-alcohols. Low molecular weight- (LFAs) and unsaturated fatty acids (UnFAs) showed diurnal variation with higher concentrations during the nighttime in summer, indicating the potential impact from microbial activities on forest aerosols. The differences of oleic acid (C18:1) and linoleic acid (C18:2) concentrations between daytime and nighttime increased at lower latitude, indicating more intense photochemical degradation occurred at lower latitude regions. High levels of n-alkanes during daytime in summer with higher values of carbon preference indexes, combining the strong odd carbon number predominance with a maximum at C27 or C29, implied the high contributions of biogenic sources, e.g., higher plant waxes. In contrast, higher concentrations of low molecular weight n-alkanes were detected in winter forest aerosols. Levoglucosan showed a positive correlation (R2 > 0.57) with high- and low molecular weight aliphatic compounds in Mt. Changbai, but such a correlation was not observed in Shennongjia and Xishuangbanna. These results suggest the significant influence of biomass burning in Mt. Changbai, and fossil fuel combustion might be another important anthropogenic source of forest aerosols. This study adds useful information to the current understanding of forest organic aerosols at different geographical locations in China.
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Affiliation(s)
- Donghuan Zhang
- School of Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Hong Ren
- School of Earth System Science, Tianjin University, Tianjin, 300072, China; Air Environmental Modeling and Pollution Controlling Key Laboratory of Sichuan Higher Education Institute, Chengdu University of Information Technology, Chengdu, 610225, China
| | - Wei Hu
- School of Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Libin Wu
- School of Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Lujie Ren
- School of Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Junjun Deng
- School of Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Qiang Zhang
- School of Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Yele Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Zifa Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
| | - Kimitaka Kawamura
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, 487-8501, Japan
| | - Pingqing Fu
- School of Earth System Science, Tianjin University, Tianjin, 300072, China.
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20
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Zhao J, Wang Y, Liu H, Wu Y, Dong W. Discrepant oxidation behavior of ferric ion and hydroxyl radical on syringic acid and vanillic acid in atmospheric Fenton-like system. CHEMOSPHERE 2022; 287:132022. [PMID: 34464849 DOI: 10.1016/j.chemosphere.2021.132022] [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: 06/01/2021] [Revised: 08/18/2021] [Accepted: 08/24/2021] [Indexed: 06/13/2023]
Abstract
Syringic acid (SA) and vanillic acid (VA) from biomass combustion are not only the potential sources of atmospheric brown carbon (BrC) but also the traceable markers of biomass burning in smoke particles. In this work, the Fenton-like oxidation in a mixed system containing SA and VA was studied under some typical conditions in atmospheric aqueous. The influence of scavenger, Fe3+ concentration, H2O2 concentration, SA concentration, pH and oxygen was discussed. Our results revealed that despite SA and VA have similar structures, Fe3+ and HO sever as their main oxidation sources, respectively. The addition of SA could heighten the HO yield obviously compared with conventional Fenton-like oxidation in atmospheric water, and this performance was attributed to the strong reducibility to Fe3+. In addition, SA accelerated the oxidation of VA and caused a 4.7-fold elevation in the initial rate. These results demonstrate that the process may change the amount of SA and VA and then disturb their mass ratio, which is important for aerosol source characterization work.
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Affiliation(s)
- Jie Zhao
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China
| | - Yu Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China
| | - Huihui Liu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China
| | - Yanlin Wu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
| | - Wenbo Dong
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
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21
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Dalton AB, Nizkorodov SA. Photochemical Degradation of 4-Nitrocatechol and 2,4-Dinitrophenol in a Sugar-Glass Secondary Organic Aerosol Surrogate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:14586-14594. [PMID: 34669384 DOI: 10.1021/acs.est.1c04975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The roles that chemical environment and viscosity play in the photochemical fate of molecules trapped in atmospheric particles are poorly understood. The goal of this work was to characterize the photolysis of 4-nitrocatechol (4NC) and 2,4-dinitrophenol (24DNP) in semisolid isomalt as a new type of surrogate for glassy organic aerosols and compare it to photolysis in liquid water, isopropanol, and octanol. UV/vis spectroscopy was used to monitor the absorbance decay to determine the rates of photochemical loss of 4NC and 24DNP. The quantum yield of 4NC photolysis was found to be smaller in an isomalt glass (2.6 × 10-6) than in liquid isopropanol (1.1 × 10-5). Both 4NC and 24NDP had much lower photolysis rates in water than in organic matrices, suggesting that they would photolyze more efficiently in organic aerosol particles than in cloud or fog droplets. Liquid chromatography in tandem with mass spectrometry was used to examine the photolysis products of 4NC. In isopropanol solution, most products appeared to result from the oxidation of 4NC, in stark contrast to photoreduction and dimerization products that were observed in solid isomalt. Therefore, the photochemical fate of 4NC, and presumably of other nitrophenols, should depend on whether they undergo photodegradation in a liquid or semisolid organic particle.
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Affiliation(s)
- Avery B Dalton
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Sergey A Nizkorodov
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
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22
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Wei J, Fang T, Lakey PSJ, Shiraiwa M. Iron-Facilitated Organic Radical Formation from Secondary Organic Aerosols in Surrogate Lung Fluid. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 56:7234-7243. [PMID: 34596401 DOI: 10.1021/acs.est.1c04334] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Respiratory deposition of secondary organic aerosols (SOA) and iron may lead to the generation of reactive oxygen species and free radicals in lung fluid to cause oxidative stress, but their underlying mechanism and formation kinetics are not well understood. Here we demonstrate substantial formation of organic radicals in surrogate lung fluid (SLF) by mixtures of Fe2+ and SOA generated from photooxidation of isoprene, α-terpineol, and toluene. The molar yields of organic radicals by SOA are measured to be 0.03-0.5% in SLF, which are 5-10 times higher than in water. We observe that Fe2+ enhances organic radical yields dramatically by a factor of 20-80, which can be attributed to Fe2+-facilitated decomposition of organic peroxides, in consistency with a positive correlation between peroxide contents and organic radical yields. Ascorbate mediates redox cycling of iron ions to sustain organic peroxide decomposition, as supported by kinetic modeling reproducing time- and concentration-dependence of organic radical formation as well as additional experiments observing the formation of Fe2+ and ascorbate radicals in mixtures of ascorbate and Fe3+. •OH and superoxide are found to be scavenged by antioxidants efficiently. These findings have implications on the role of organic radicals in oxidative damage and lipid peroxidation.
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Affiliation(s)
- Jinlai Wei
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Ting Fang
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Pascale S J Lakey
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Manabu Shiraiwa
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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23
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A Study on Indoor Particulate Matter Variation in Time Based on Count and Sizes and in Relation to Meteorological Conditions. SUSTAINABILITY 2021. [DOI: 10.3390/su13158263] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
An important aspect of air pollution analysis consists of the varied presence of particulate matter in analyzed air samples. In this respect, the present work aims to present a case study regarding the evolution in time of quantified particulate matter of different sizes. This study is based on data acquisitioned in an indoor location, already used in a former particulate matter-related article; thus, it can be considered as a continuation of that study, with the general aim to demonstrate the necessity to expand the existing network for pollution monitoring. Besides particle matter quantification, a correlation of the obtained results is also presented against meteorological data acquisitioned by the National Air Quality Monitoring Network. The transformation of quantified PM data in mass per volume and a comparison with other results are also addressed.
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