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Enami S, Numadate N, Hama T. Atmospheric Intermediates at the Air-Water Interface. J Phys Chem A 2024; 128:5419-5434. [PMID: 38968003 PMCID: PMC11264275 DOI: 10.1021/acs.jpca.4c02889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/10/2024] [Accepted: 06/14/2024] [Indexed: 07/07/2024]
Abstract
The air-water interface (AWI) is a ubiquitous reaction field different from the bulk phase where unexpected reactions and physical processes often occur. The AWI is a region where air contacts cloud droplets, aerosol particles, the ocean surface, and biological surfaces such as fluids that line human epithelia. In Earth's atmosphere, short-lived intermediates are expected to be generated at the AWI during multiphase reactions. Recent experimental developments have enabled the direct detection of atmospherically relevant, short-lived intermediates at the AWI. For example, spray ionization mass spectrometric analysis of water microjets exposed to a gaseous mixture of ozone and water vapor combined with a 266 nm laser flash photolysis system (LFP-SIMS) has been used to directly probe organic peroxyl radicals (RO2·) produced by interfacial hydroxyl radicals (OH·) + organic compound reactions. OH· emitted immediately after the laser flash photolysis of carboxylic acid at the gas-liquid interface have been directly detected by time-resolved, laser-induced florescence techniques that can be used to study atmospheric multiphase photoreactions. In this Featured Article, we show some recent experimental advances in the detection of atmospherically important intermediates at the AWI and the associated reaction mechanisms. We also discuss current challenges and future prospects for atmospheric multiphase chemistry.
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Affiliation(s)
- Shinichi Enami
- Department
of Chemistry, Graduate School of Science and Technology, University of Tsukuba, Tsukuba 305-8571, Japan
| | - Naoki Numadate
- Department
of Chemistry, Graduate School of Science and Technology, University of Tsukuba, Tsukuba 305-8571, Japan
| | - Tetsuya Hama
- Komaba
Institute for Science and Department of Basic Science, The University of Tokyo, Meguro, Tokyo 153-8902, Japan
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2
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Błaziak A, Schaefer T, Rudziński K, Herrmann H. Photo-Oxidation of α-Pinene Oxidation Products in Atmospheric Waters - pH- and Temperature-Dependent Kinetic Studies. J Phys Chem A 2024; 128:4507-4516. [PMID: 38780772 DOI: 10.1021/acs.jpca.4c02075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
The atmospheric α-pinene oxidation leads to three carboxylic acids: norpinonic acid (NPA), pinic acid (PA), and 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA). In this study, the OH radical kinetics in the aqueous phase of these carboxylic acids were investigated at different temperatures and pH values of solutions. Activation parameters and the corresponding atmospheric lifetimes of the acids in the troposphere were derived. The overall second-order rate constants for the individual speciation forms of the acids (AH and A- for NPA; AH2, AH- and A2- for PA; and AH3, AH2-, AH2- and A3- for MBTCA) were determined. At 298 K, the rate constants for reactions of protonated forms (AHx) of NPA, PA, and MBTCA with •OH, were (1.5 ± 0.2) × 109 L mol-1 s-1, (2.4 ± 0.1) × 109 L mol-1 s-1, and (4.1 ± 0.6) × 108 L mol-1 s-1, respectively. For the fully deprotonated forms (Ax-) of studied acids, the second-order rate constants were (2.2 ± 0.2) × 109 L mol-1 s-1, (2.8 ± 0.1) × 109 L mol-1 s-1, and (10.2 ± 0.7) × 108 L mol-1 s-1 at 298 K, respectively. It was found that the reactions of NPA and PA with OH radicals are faster than with MBTCA. For MBTCA, the reaction rate depends on pH more strongly at elevated temperatures (>298 K). The atmospheric lifetimes of the acids considered due to their reactivity with •OH were calculated for different model scenarios at a temperature of 283 K and pH = 2 in the aqueous phase. For this purpose, liquid water content (LWC) was used for aerosols and clouds under storm conditions and at various aqueous-phase concentrations of OH radicals. The lifetimes decreased with increasing LWC (from 10-12 m3 m-3 in aerosol to 10-5 m3 m-3 in storms), indicating that the acids undergo significant aqueous processing under realistic atmospheric conditions. Besides, the aerosol systems appeared less effective in removing PA and NPA, with lifetimes ranging from hundreds of days to tens and hundreds of hours, respectively. Clouds were more effective, with lifetimes ranging from tens of hours to a single second or less. MBTCA, which dissolves better in water, was effectively removed in all systems, with the longest lifetime of approximately 90 min.
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Affiliation(s)
- Agata Błaziak
- Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Thomas Schaefer
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
| | - Krzysztof Rudziński
- Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Hartmut Herrmann
- Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Permoserstraße 15, 04318 Leipzig, Germany
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Witkowski B, al-Sharafi M, Błaziak K, Gierczak T. Aging of α-Pinene Secondary Organic Aerosol by Hydroxyl Radicals in the Aqueous Phase: Kinetics and Products. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6040-6051. [PMID: 37014140 PMCID: PMC10116591 DOI: 10.1021/acs.est.2c07630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 03/20/2023] [Accepted: 03/20/2023] [Indexed: 06/19/2023]
Abstract
The reaction of hydroxyl radicals (OH) with a water-soluble fraction of the α-pinene secondary organic aerosol (SOA) was investigated using liquid chromatography coupled with negative electrospray ionization mass spectrometry. The SOA was generated by the dark ozonolysis of α-pinene, extracted into the water, and subjected to chemical aging by the OH. Bimolecular reaction rate coefficients (kOH) for the oxidation of terpenoic acids by the OH were measured using the relative rate method. The unaged SOA was dominated by the cyclobutyl-ring-retaining compounds, primarily cis-pinonic, cis-pinic, and hydroxy-pinonic acids. Aqueous oxidation by the OH resulted in the removal of early-stage products and dimers, including well-known oligomers with MW = 358 and 368 Da. Furthermore, a 2- to 5-fold increase in the concentration of cyclobutyl-ring-opening products was observed, including terpenylic and diaterpenylic acids and diaterpenylic acid acetate as well as some of the newly identified OH aging markers. At the same time, results obtained from the kinetic box model showed a high degree of SOA fragmentation following the reaction with the OH, which indicates that non-radical reactions occurring during the evaporation of water likely contribute to the high yields of terpenoic aqSOAs reported previously. The estimated atmospheric lifetimes showed that in clouds, terpenoic acids react with the OH exclusively in the aqueous phase. Aqueous OH aging of the α-pinene SOA results in a 10% increase of the average O/C ratio and a 3-fold decrease in the average kOH value, which is likely to affect the cloud condensation nuclei activity of the aqSOA formed after the evaporation of water.
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Sun J, Yin Y, Li W, Jin O, Na N. CHEMICAL REACTION MONITORING BY AMBIENT MASS SPECTROMETRY. MASS SPECTROMETRY REVIEWS 2022; 41:70-99. [PMID: 33259644 DOI: 10.1002/mas.21668] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/16/2020] [Accepted: 10/22/2020] [Indexed: 06/12/2023]
Abstract
Chemical reactions conducted in different media (liquid phase, gas phase, or surface) drive developments of versatile techniques for the detection of intermediates and prediction of reasonable reaction pathways. Without sample pretreatment, ambient mass spectrometry (AMS) has been applied to obtain structural information of reactive molecules that differ in polarity and molecular weight. Commercial ion sources (e.g., electrospray ionization, atmospheric pressure chemical ionization, and direct analysis in real-time) have been reported to monitor substrates and products by offline reaction examination. While the interception or characterization of reactive intermediates with short lifetime are still limited by the offline modes. Notably, online ionization technologies, with high tolerance to salt, buffer, and pH, can achieve direct sampling and ionization of on-going reactions conducted in different media (e.g., liquid phase, gas phase, or surface). Therefore, short-lived intermediates could be captured at unprecedented timescales, and the reaction dynamics could be studied for mechanism examinations without sample pretreatments. In this review, via various AMS methods, chemical reaction monitoring and mechanism elucidation for different classifications of reactions have been reviewed. The developments and advances of common ionization methods for offline reaction monitoring will also be highlighted.
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Affiliation(s)
- Jianghui Sun
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
| | - Yiyan Yin
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
| | - Weixiang Li
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
| | - Ouyang Jin
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
| | - Na Na
- Key Laboratory of Radiopharmaceuticals Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, People's Republic of China
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Qiu J, Ishizuka S, Tonokura K, Sato K, Inomata S, Enami S. Effects of pH on Interfacial Ozonolysis of α-Terpineol. J Phys Chem A 2019; 123:7148-7155. [PMID: 31329444 DOI: 10.1021/acs.jpca.9b05434] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Acidity changes the physical properties of atmospheric aerosol particles and the mechanisms of reactions that occur therein and on the surface. Here, we used surface-sensitive pneumatic ionization mass spectrometry to investigate the effects of pH on the heterogeneous reactions of aqueous α-terpineol (C10H17OH), a representative monoterpene alcohol, with gaseous ozone. Rapid (≤10 μs) ozonolysis of α-terpineol produced Criegee intermediates (CIs, zwitterionic/diradical carbonyl oxides) on the surface of water microjets. We studied the effects of microjet bulk pH (1-11) on the formation of functionalized carboxylate and α-hydroxy-hydroperoxide chloride adduct (HH-Cl-) products generated by isomerization and hydration of α-terpineol CIs, respectively. Compared with the signal at pH ≈ 6, the mass spectral signal of HH-Cl- was less intense under both basic and more acidic conditions, whereas the intensity of the functionalized carboxylate signal increased with increasing pH up to 4 and then remained constant. The decrease of HH-Cl- signals at bulk pH values of >6 is attributable to the accumulation of OH- at the air-water interface that suppresses the relative abundance of hydrophilic HH and Cl-. The present study suggests that α-terpineol in ambient aqueous organic aerosols will be converted into much lower volatile and potentially toxic organic hydroperoxides during the heterogeneous ozonolysis.
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Affiliation(s)
- Junting Qiu
- Graduate School of Frontier Sciences , The University of Tokyo , 5-1-5 Kashiwanoha , Kashiwa 277-8563 , Japan
| | - Shinnosuke Ishizuka
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
| | - Kenichi Tonokura
- Graduate School of Frontier Sciences , The University of Tokyo , 5-1-5 Kashiwanoha , Kashiwa 277-8563 , Japan
| | - Kei Sato
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
| | - Satoshi Inomata
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
| | - Shinichi Enami
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
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Witkowski B, Al-Sharafi M, Gierczak T. Ozonolysis of β-Caryophyllonic and Limononic Acids in the Aqueous Phase: Kinetics, Product Yield, and Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8823-8832. [PMID: 31296007 DOI: 10.1021/acs.est.9b02471] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Ozonolysis of β-caryophyllonic (BCA) and limononic (LA) acids in the aqueous-phase was investigated. The rate coefficients (kozone) measured for the BCA + ozone (O3) reaction at 295 ± 2 K were 4.8 ± 0.6 × 105 M-1 s-1 at pH = 2 and 6.0 ± 0.3 × 105 M-1 s-1 at pH = 8. The UV-vis absorption cross sections (σ, cm2 molecule-1) for BCA and LA in water were also measured. Atmospheric lifetimes of BCA and LA due to reactions with O3, hydroxyl radicals (OH), and due to photolysis were calculated. Lifetime estimates indicate that the aqueous-phase processing of both terpenoic acids studied in this work would be relevant in the atmosphere. In cloudwater, BCA is more likely to react with O3 with some possible contribution from the oxidation by OH, whereas the opposite is true for LA. Products of BCA and LA ozonolysis were quantified with LC-MS as well as with the UV-vis assays for quantification of formaldehyde and hydroperoxides. Oxygenated derivatives of BCA and LA that were produced following aqueous ozonolysis were identified as keto-BCA and keto-LA, respectively. Additionally, large quantities of intramolecular secondary ozonides and α-acyloxyhydroperoxy aldehydes were tentatively identified as products of aqueous ozonolysis of the two unsaturated terpenoic acids investigated.
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Affiliation(s)
- Bartłomiej Witkowski
- Faculty of Chemistry , University of Warsaw , Al. Żwirki i Wigury 101 , Warsaw , 02-089 , Poland
| | - Mohammed Al-Sharafi
- Faculty of Chemistry , University of Warsaw , Al. Żwirki i Wigury 101 , Warsaw , 02-089 , Poland
| | - Tomasz Gierczak
- Faculty of Chemistry , University of Warsaw , Al. Żwirki i Wigury 101 , Warsaw , 02-089 , Poland
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Sbai SE, Farida B. Study of Iodine Oxide Particles at the Air/Sea Interface in the Presence of Surfactants and Humic Acid. CHEMISTRY & CHEMICAL TECHNOLOGY 2019. [DOI: 10.23939/chcht13.03.341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Qiu J, Ishizuka S, Tonokura K, Enami S. Interfacial vs Bulk Ozonolysis of Nerolidol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5750-5757. [PMID: 31017766 DOI: 10.1021/acs.est.9b00364] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ozone readily reacts with olefins with the formation of more reactive Criegee intermediates (CIs). The transient CIs impact HO x cycles, and they play a role in new particle formation in the troposphere. Oxidation by O3 occurs both in the gas-phase, in the liquid phase, and at air-water and air-aerosol interfaces. In light of the importance of O3 in environmental and engineered chemical transformations, we have investigated the ozonolysis mechanisms of a triolefin C15-alcohol, nerolidol (Nero, a biogenic sesquiterpene), at the air-water interface in the presence of acetonitrile. Surface-sensitive pneumatic ionization mass spectrometric detection of α-hydroxy-hydroperoxides and functionalized carboxylates, generated by the hydration and isomerization of CIs, respectively, enables us to evaluate the relative reactivity of each C=C toward O3. In addition, we compare bulk-phase ozonolysis chemistry to similar reactions taking place at the air-water interface. Our experimental results show that O3 reacts primarily with the (CH3)2C=CH- and -(CH3)C=CH- moieties (>∼98%), while the O3 attack on the terminal -HC=CH2 site (<∼2%) is a minor pathway during both interfacial and bulk ozonolysis. The presence of functionalized-carboxylates on interfaces but not in bulk-phase reactions with O3 indicates that the isomerization of the CIs is not hindered at the air-water interface due to the lower availability of water .
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Affiliation(s)
- Junting Qiu
- Graduate School of Frontier Sciences , The University of Tokyo , 5-1-5 Kashiwanoha , Kashiwa 277-8563 , Japan
| | - Shinnosuke Ishizuka
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
| | - Kenichi Tonokura
- Graduate School of Frontier Sciences , The University of Tokyo , 5-1-5 Kashiwanoha , Kashiwa 277-8563 , Japan
| | - Shinichi Enami
- National Institute for Environmental Studies , 16-2 Onogawa , Tsukuba 305-8506 , Japan
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Enami S, Colussi AJ. OH-Radical Oxidation of Lung Surfactant Protein B on Aqueous Surfaces. Mass Spectrom (Tokyo) 2018; 7:S0077. [PMID: 30533342 PMCID: PMC6245955 DOI: 10.5702/massspectrometry.s0077] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/11/2018] [Indexed: 11/23/2022] Open
Abstract
Air pollutants generate reactive oxygen species on lung surfaces. Here we report how hydroxyl radicals (·OH) injected on the surface of water react with SP-B1-25, a 25-residue polypeptide surrogate of human lung surfactant protein B. Our experiments consist of intersecting microjets of aqueous SP-B1-25 solutions with O3/O2/H2O/N2(g) gas streams that are photolyzed into ·OH(g) in situ by 266 nm laser nanosecond pulses. Surface-sensitive mass spectrometry enables us to monitor the prompt (<10 μs) and simultaneous formation of primary O n -containing products/intermediates (n≤5) triggered by the reaction of ·OH with interfacial SP-B1-25. We found that O-atoms from both O3 and ·OH are incorporated into the reactive cysteine Cys8 and Cys11 and tryptophan Trp9 components of the hydrophobic N-terminus of SP-B1-25 that lies at the topmost layers of the air-liquid interface. Remarkably, these processes are initiated by ·OH additions rather than by H-atom abstractions from S-H, C-H, or N-H groups. By increasing the hydrophilicity of the N-terminus region of SP-B1-25, these transformations will impair its role as a surfactant.
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Affiliation(s)
| | - Agustín J Colussi
- Linde Center for Global Environmental Science, California Institute of Technology
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Otto T, Schaefer T, Herrmann H. Aqueous-Phase Oxidation of Terpene-Derived Acids by Atmospherically Relevant Radicals. J Phys Chem A 2018; 122:9233-9241. [PMID: 30359526 DOI: 10.1021/acs.jpca.8b08922] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Terpene-derived acids formed through the atmospheric gas-phase oxidation of terpenes are able to efficiently undergo a phase transfer into the aqueous phase. The subsequent aqueous-phase oxidation of such compounds has not been intensely studied. Accordingly, the aqueous-phase second-order rate constants of the oxidation reactions of cis-pinonic acid (CPA) and (+)-camphoric acid (+CA) with hydroxyl radicals (•OH), nitrate radicals (NO3•), and sulfate radicals (SO4•-) were investigated as a function of temperature and pH in the present study. For CPA and +CA the following •OH reaction rate constants at T = 298 K are determined: ksecond(CPA, pH<2) = (2.8 ± 0.1) × 109 L mol-1 s-1, ksecond(CPA, pH>8) = (2.7 ± 0.3) × 109 L mol-1 s-1, ksecond(+CA, pH<2) = (2.1 ± 0.1) × 109 L mol-1 s-1, ksecond(+CA, pH=5.3) = (2.7 ± 0.3) × 109 L mol-1 s-1, ksecond(+CA, pH>8) = (2.7 ± 0.1) × 109 L mol-1 s-1. In order to assess the atmospheric impact of the aqueous-phase oxidation of such compounds, atmospheric aqueous-phase lifetimes were calculated for two model scenarios based on CAPRAM 3.0i. The aqueous-phase oxidation under remote conditions emerges to be the most favored pathway with lifetimes of 5 ± 1 h.
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Affiliation(s)
- Tobias Otto
- Atmospheric Chemistry Department (ACD) , Leibniz-Institute for Tropospheric Research (TROPOS) , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Thomas Schaefer
- Atmospheric Chemistry Department (ACD) , Leibniz-Institute for Tropospheric Research (TROPOS) , Permoserstrasse 15 , 04318 Leipzig , Germany
| | - Hartmut Herrmann
- Atmospheric Chemistry Department (ACD) , Leibniz-Institute for Tropospheric Research (TROPOS) , Permoserstrasse 15 , 04318 Leipzig , Germany
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12
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13
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Modeling Heterogeneous Oxidation of NOx, SO2 and Hydrocarbons in the Presence of Mineral Dust Particles under Various Atmospheric Environments. ACTA ACUST UNITED AC 2018. [DOI: 10.1021/bk-2018-1299.ch015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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14
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Witkowski B, Al-Sharafi M, Gierczak T. Kinetics of Limonene Secondary Organic Aerosol Oxidation in the Aqueous Phase. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11583-11590. [PMID: 30207709 DOI: 10.1021/acs.est.8b02516] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Twenty semivolatile organic compounds that contribute to limonene secondary organic aerosol (SOA) were synthesized in the flow-tube reactor. Kinetics of the aqueous-phase oxidation of the synthesized compounds by hydroxyl radicals (OH) and ozone (O3) were investigated at 298 ± 2 K using the relative rate method. Oxidized organic compounds identified as the major components of limonene SOA were quantified with liquid chromatography coupled to the electrospray ionization and quadrupole tandem mass spectrometry (LC-ESI/MS/MS). The bimolecular rate coefficients measured for the oxidation products of limonene are kOH = 2-5 × 109 M-1 s-1 for saturated and kOH = 1-2 × 1010 M-1 s-1 for unsaturated compounds. Ozonolysis reaction bimolecular rate coefficients obtained for the unsaturated compounds in the aqueous phase are between 2 and 6 × 104 M-1 s-1. The results obtained in this work also indicate that oxidation of limonene carboxylic acids by OH was about a factor of 2 slower for the carboxylate ions than for the protonated acids while the opposite was true for the ozonolysis. The data acquired provided new insights into kinetics of the limonene SOA processing in the aqueous phase. Ozonolysis of limonene SOA also increased the concentration of dimers, most likely due to reactions of the stabilized Criegee intermediates with the other, stable products. These results indicate that aqueous-phase oxidation of limonene SOA by OH and O3 will be relevant in clouds, fogs, and wet aerosols.
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Affiliation(s)
- Bartłomiej Witkowski
- University of Warsaw , Faculty of Chemistry , Al. Żwirki i Wigury 101 , 02-089 Warsaw , Poland
| | - Mohammed Al-Sharafi
- University of Warsaw , Faculty of Chemistry , Al. Żwirki i Wigury 101 , 02-089 Warsaw , Poland
| | - Tomasz Gierczak
- University of Warsaw , Faculty of Chemistry , Al. Żwirki i Wigury 101 , 02-089 Warsaw , Poland
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15
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Qiu J, Ishizuka S, Tonokura K, Colussi AJ, Enami S. Reactivity of Monoterpene Criegee Intermediates at Gas–Liquid Interfaces. J Phys Chem A 2018; 122:7910-7917. [DOI: 10.1021/acs.jpca.8b06914] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Junting Qiu
- Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8563, Japan
| | - Shinnosuke Ishizuka
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
| | - Kenichi Tonokura
- Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8563, Japan
| | - Agustín J. Colussi
- Ronald and Maxine Linde Center for Global Environmental Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Shinichi Enami
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
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16
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Huang Y, Barraza KM, Kenseth CM, Zhao R, Wang C, Beauchamp JL, Seinfeld JH. Probing the OH Oxidation of Pinonic Acid at the Air–Water Interface Using Field-Induced Droplet Ionization Mass Spectrometry (FIDI-MS). J Phys Chem A 2018; 122:6445-6456. [DOI: 10.1021/acs.jpca.8b05353] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Yuanlong Huang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, United States
| | - Kevin M. Barraza
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Christopher M. Kenseth
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Ran Zhao
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Chen Wang
- Department of Chemistry and Department of Physical and Environmental Sciences, University of Toronto, Toronto, Ontario M1C 1A4, Canada
| | - J. L. Beauchamp
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - John H. Seinfeld
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United States
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Qiu J, Ishizuka S, Tonokura K, Enami S. Reactions of Criegee Intermediates with Benzoic Acid at the Gas/Liquid Interface. J Phys Chem A 2018; 122:6303-6310. [DOI: 10.1021/acs.jpca.8b04995] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Junting Qiu
- Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8563, Japan
| | - Shinnosuke Ishizuka
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
| | - Kenichi Tonokura
- Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8563, Japan
| | - Shinichi Enami
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
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18
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Witkowski B, Jurdana S, Gierczak T. Limononic Acid Oxidation by Hydroxyl Radicals and Ozone in the Aqueous Phase. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:3402-3411. [PMID: 29444406 DOI: 10.1021/acs.est.7b04867] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Kinetics and mechanism of limononic acid (3-isopropenyl-6-oxoheptanoic acid, LA) oxidation by hydroxyl radicals (OH) and ozone (O3) were studied in the aqueous phase at 298 ± 2 K. These reactions were investigated using liquid chromatography coupled to the electrospray ionization and quadrupole tandem mass spectrometry (LC-ESI/MS/MS). The rate coefficients determined for LA + OH reaction were: 1.3 ± 0.3 × 1010 M-1 s-1 at pH = 2 and 5.7 ± 0.6 × 109 M-1 s-1 at pH = 10. The rate coefficient determined for LA ozonolysis was 4.2 ± 0.2 × 104 M-1 s-1 at pH = 2. The calculated Henry's law constant (H) for LA was ca. 6.3 × 106 M × atm-1, thereby indicating that in fogs and clouds with LWC = 0.3-0.5 g × m-3 LA will reside entirely in the aqueous phase. Calculated atmospheric lifetimes due to reaction with OH and O3 strongly indicate that aqueous-phase oxidation can be important for LA under realistic atmospheric conditions. Under acidic conditions, the aqueous-phase oxidation of LA by OH will dominate over reaction with O3, whereas the opposite is more likely when pH ≥ 4.5. The aqueous-phase oxidation of LA produced keto-limononic acid and a number of low-volatility products, such as hydroperoxy-LA and α-hydroxyhydroperoxides.
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Affiliation(s)
- Bartłomiej Witkowski
- University of Warsaw , Faculty of Chemistry , Al. Żwirki i Wigury 101 , 02-089 Warsaw , Poland
| | - Sara Jurdana
- University of Warsaw , Faculty of Chemistry , Al. Żwirki i Wigury 101 , 02-089 Warsaw , Poland
| | - Tomasz Gierczak
- University of Warsaw , Faculty of Chemistry , Al. Żwirki i Wigury 101 , 02-089 Warsaw , Poland
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19
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Enami S, Hoffmann MR, Colussi AJ. Extensive H-atom abstraction from benzoate by OH-radicals at the air-water interface. Phys Chem Chem Phys 2018; 18:31505-31512. [PMID: 27827491 DOI: 10.1039/c6cp06652f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Much is known about OH-radical chemistry in the gas-phase and bulk water. Important atmospheric and biological processes, however, involve little investigated OH-radical reactions at aqueous interfaces with hydrophobic media. Here, we report the online mass-specific identification of the products and intermediates generated on the surface of aqueous (H2O, D2O) benzoate-h5 and -d5 microjets by ∼8 ns ˙OH(g) pulses in air at 1 atm. Isotopic labeling lets us unambiguously identify the phenylperoxyl radicals that ensue H-abstraction from the aromatic ring and establish a lower bound (>26%) to this process as it takes place in the interfacial water nanolayers probed by our experiments. The significant extent of H-abstraction vs. its negligible contribution both in the gas-phase and bulk water underscores the unique properties of the air-water interface as a reaction medium. The enhancement of H-atom abstraction in interfacial water is ascribed, in part, to the relative destabilization of a more polar transition state for OH-radical addition vs. H-abstraction due to incomplete hydration at the low water densities prevalent therein.
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Affiliation(s)
- Shinichi Enami
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
| | - Michael R Hoffmann
- Linde Center for Global Environmental Science, California Institute of Technology, California 91125, USA.
| | - Agustín J Colussi
- Linde Center for Global Environmental Science, California Institute of Technology, California 91125, USA.
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20
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Laskin A, Lin P, Laskin J, Fleming LT, Nizkorodov S. Molecular Characterization of Atmospheric Brown Carbon. ACS SYMPOSIUM SERIES 2018. [DOI: 10.1021/bk-2018-1299.ch013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Alexander Laskin
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47906, United States
| | - Peng Lin
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47906, United States
| | - Julia Laskin
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47906, United States
| | - Lauren T. Fleming
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Sergey Nizkorodov
- Department of Chemistry, University of California, Irvine, California 92697, United States
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21
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Ishizuka S, Matsugi A, Hama T, Enami S. Chain-propagation, chain-transfer, and hydride-abstraction by cyclic carbocations on water surfaces. Phys Chem Chem Phys 2018; 20:25256-25267. [DOI: 10.1039/c8cp04993a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New mechanisms for the growth and increase in complexity of atmospheric aerosol particles are elucidated. The present findings will also be useful for interfacial polymer/oligomer synthesis.
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Affiliation(s)
| | - Akira Matsugi
- Research Institute of Science for Safety and Sustainability
- National Institute of Advanced Industrial Science and Technology
- Tsukuba 305-8569
- Japan
| | - Tetsuya Hama
- Institute of Low Temperature Science
- Hokkaido University
- Sapporo 060-0819
- Japan
| | - Shinichi Enami
- National Institute for Environmental Studies
- Tsukuba 305-8506
- Japan
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22
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Verma V, Sioutas C, Weber RJ. Oxidative Properties of Ambient Particulate Matter - An Assessment of the Relative Contributions from Various Aerosol Components and Their Emission Sources. ACS SYMPOSIUM SERIES 2018. [DOI: 10.1021/bk-2018-1299.ch019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Vishal Verma
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, Illinois 61801, United States
| | - Constantinos Sioutas
- Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Rodney J. Weber
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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23
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Shiraiwa M, Ueda K, Pozzer A, Lammel G, Kampf CJ, Fushimi A, Enami S, Arangio AM, Fröhlich-Nowoisky J, Fujitani Y, Furuyama A, Lakey PSJ, Lelieveld J, Lucas K, Morino Y, Pöschl U, Takahama S, Takami A, Tong H, Weber B, Yoshino A, Sato K. Aerosol Health Effects from Molecular to Global Scales. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:13545-13567. [PMID: 29111690 DOI: 10.1021/acs.est.7b04417] [Citation(s) in RCA: 208] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Poor air quality is globally the largest environmental health risk. Epidemiological studies have uncovered clear relationships of gaseous pollutants and particulate matter (PM) with adverse health outcomes, including mortality by cardiovascular and respiratory diseases. Studies of health impacts by aerosols are highly multidisciplinary with a broad range of scales in space and time. We assess recent advances and future challenges regarding aerosol effects on health from molecular to global scales through epidemiological studies, field measurements, health-related properties of PM, and multiphase interactions of oxidants and PM upon respiratory deposition. Global modeling combined with epidemiological exposure-response functions indicates that ambient air pollution causes more than four million premature deaths per year. Epidemiological studies usually refer to PM mass concentrations, but some health effects may relate to specific constituents such as bioaerosols, polycyclic aromatic compounds, and transition metals. Various analytical techniques and cellular and molecular assays are applied to assess the redox activity of PM and the formation of reactive oxygen species. Multiphase chemical interactions of lung antioxidants with atmospheric pollutants are crucial to the mechanistic and molecular understanding of oxidative stress upon respiratory deposition. The role of distinct PM components in health impacts and mortality needs to be clarified by integrated research on various spatiotemporal scales for better evaluation and mitigation of aerosol effects on public health in the Anthropocene.
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Affiliation(s)
- Manabu Shiraiwa
- Department of Chemistry, University of California , Irvine, California 92697, United States
| | - Kayo Ueda
- Kyoto University , Kyoto 606-8501, Japan
| | | | - Gerhard Lammel
- Research Centre for Toxic Compounds in the Environment, Masaryk University , 625 00 Brno, Czech Republic
| | - Christopher J Kampf
- Institute for Organic Chemistry, Johannes Gutenberg University , 55122 Mainz, Germany
| | - Akihiro Fushimi
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Shinichi Enami
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Andrea M Arangio
- Swiss Federal Institute of Technology in Lausanne (EPFL) , Lausanne 1015, Switzerland
| | | | - Yuji Fujitani
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Akiko Furuyama
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Pascale S J Lakey
- Department of Chemistry, University of California , Irvine, California 92697, United States
| | | | | | - Yu Morino
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | | | - Satoshi Takahama
- Swiss Federal Institute of Technology in Lausanne (EPFL) , Lausanne 1015, Switzerland
| | - Akinori Takami
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | | | | | - Ayako Yoshino
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Kei Sato
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
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24
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Witkowski B, Gierczak T. cis-Pinonic Acid Oxidation by Hydroxyl Radicals in the Aqueous Phase under Acidic and Basic Conditions: Kinetics and Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:9765-9773. [PMID: 28719200 DOI: 10.1021/acs.est.7b02427] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Aqueous-phase oxidation of cis-pinonic acid (CPA) by hydroxyl radicals (OH) was studied using a relative rate technique under acidic and basic conditions. Liquid chromatography (LC) coupled to the negative electrospray ionization (ESI) quadrupole tandem mass spectrometry (MS/MS) was used to monitor the concentrations of CPA and reference compounds. The measured second order reaction rate coefficients of CPA with OH were: 3.6 ± 0.3 × 109 M-1 s-1 (pH 2) and 3.0 ± 0.3 × 109 M-1 s-1 (pH 10) - combined uncertainties are 2σ. These results indicated that the lifetimes of CPA in the atmosphere are most likely independent from the aqueous-phase pH. LC-ESI/MS/MS was also used to tentatively identify the CPA oxidation products. Formation of carboxylic acids with molecular weight (MW) 216 Da (most likely C10H16O5) and MW 214 Da (C10H14O5) was confirmed with LC-ESI/MS/MS. When the initial CPA concentration was increased from 0.3 to 10 mM, formation of additional products was observed with MW 188, 200, 204, and 232 Da. Hydroperoxy, hydroxyl and carbonyl-substituted CPA derivatives were tentatively identified among the products. Similar products were formed by the CPA oxidation by OH in the gas-phase, at the air-water interface as well as in the solid phase (dry film). Formation of the stable adduct of CPA and H2O2 was also observed when the reaction mixture was evaporated to dryness and redissolved in water. Acquired mass spectrometric data argues against formation of oligomers.
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Affiliation(s)
- Bartłomiej Witkowski
- University of Warsaw , Faculty of Chemistry, Al. Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Tomasz Gierczak
- University of Warsaw , Faculty of Chemistry, Al. Żwirki i Wigury 101, 02-089 Warsaw, Poland
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25
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Enami S, Hoffmann MR, Colussi AJ. Criegee Intermediates React with Levoglucosan on Water. J Phys Chem Lett 2017; 8:3888-3894. [PMID: 28767252 DOI: 10.1021/acs.jpclett.7b01665] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Levoglucosan (Levo), a C6-anhydrosaccharide produced in the combustion of cellulosic materials, is the major component of aerosols produced from biomass burning over vast regions worldwide. Levo has long been considered chemically inert and thus has been used as a tracer of biomass burning sources. However, we now show that sugars including Levo, glucose, arabitol, and mannitol react rapidly with Criegee intermediates (CIs) generated during the ozonolysis of sesquiterpenes on the surface of water:acetonitrile microjets. Hydrophilic Levo reacts faster with CIs than with water or surface-active 1-octanol at air-aqueous interfaces. This unexpected phenomenon is likely associated with the relatively low water density at air-aqueous interfaces coupled with a higher gas-phase acidity of the saccharide hydroxyl groups (i.e., -OH) versus n-alkanols. Results presented herein show that aerosol saccharides are in fact reactive toward CIs. Given the abundance of saccharides in the atmosphere, they may be important contributors to the growth and mass loading of secondary organic aerosols.
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Affiliation(s)
- Shinichi Enami
- National Institute for Environmental Studies , 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Michael R Hoffmann
- Linde Center for Global Environmental Science, California Institute of Technology , Pasadena, California 91125, United States
| | - A J Colussi
- Linde Center for Global Environmental Science, California Institute of Technology , Pasadena, California 91125, United States
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26
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Liu MJ, Wiegel AA, Wilson KR, Houle FA. Aerosol Fragmentation Driven by Coupling of Acid–Base and Free-Radical Chemistry in the Heterogeneous Oxidation of Aqueous Citric Acid by OH Radicals. J Phys Chem A 2017; 121:5856-5870. [DOI: 10.1021/acs.jpca.7b04892] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew J. Liu
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94702, United States
- Department
of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Aaron A. Wiegel
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94702, United States
| | - Kevin R. Wilson
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94702, United States
| | - Frances A. Houle
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94702, United States
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27
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Enami S, Colussi AJ. Reactions of Criegee Intermediates with Alcohols at Air-Aqueous Interfaces. J Phys Chem A 2017. [PMID: 28635281 DOI: 10.1021/acs.jpca.7b04272] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The fate of Criegee intermediates (CIs) from the gas-phase ozonolysis of unsaturated organic compounds in the troposphere is largely controlled by their reactions with water vapor. We recently found that against all expectations carboxylic acids compete at millimolar concentrations with water for CIs at the air-liquid interface of aqueous organic media. This outcome is consistent with both the low water concentration in the outermost interfacial layers and the enrichment of the competing acids therein. Here we show, via online electrospray mass spectrometric detection, that CIs generated in situ in the fast ozonolysis of sesquiterpenes (C15H24) on the surface of water:acetonitrile microjets react with n ≥ 4 linear alcohols CnH2n+1OH to produce high molecular weight C15+n ethers in one step. The OH group of 1-octanol proved to be ∼25 times less reactive than that of n-octanoic toward CIs at the same bulk molar concentration, revealing that the reactivity of hydroxylic species depends on both acidities and interfacial affinities. CI interfacial reactions with surface-active hydroxylic species, by bypassing water, represent shortcuts to molecular complexity in atmospheric aerosols.
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Affiliation(s)
- Shinichi Enami
- National Institute for Environmental Studies , 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - A J Colussi
- Linde Center for Global Environmental Science, California Institute of Technology , Pasadena, California 91125, United States
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28
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Xiao P, Wang Q, Fang WH, Cui G. Quantum Chemical Investigation on Photochemical Reactions of Nonanoic Acids at Air-Water Interface. J Phys Chem A 2017; 121:4253-4262. [PMID: 28513156 DOI: 10.1021/acs.jpca.7b03123] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Photoinduced chemical reactions of organic compounds at the marine boundary layer have recently attracted significant experimental attention because this kind of photoreactions has been proposed to have substantial impact on local new particle formation and their photoproducts could be a source of secondary organic aerosols. In this work, we have employed first-principles density functional theory method combined with cluster models to systematically explore photochemical reaction pathways of nonanoic acids (NAs) to form volatile saturated and unsaturated C9 and C8 aldehydes at air-water interfaces. On the basis of the results, we have found that the formation of C9 aldehydes is not initiated by intermolecular Norrish type II reaction between two NAs but by intramolecular T1 C-O bond fission of NA generating acyl and hydroxyl radicals. Subsequently, saturated C9 aldehydes are formed through hydrogenation reaction of acyl radical by another intact NA. Following two dehydrogenation reactions, unsaturated C9 aldehydes are generated. In parallel, the pathway to C8 aldehydes is initiated by T1 C-C bond fission of NA, which generates octyl and carboxyl radicals; then, an octanol is formed through recombination reaction of octyl with hydroxyl radical. In the following, two dehydrogenation reactions result into an enol intermediate from which saturated C8 aldehydes are produced via NA-assisted intermolecular hydrogen transfer. Finally, two dehydrogenation reactions generate unsaturated C8 aldehydes. In these reactions, water and NA molecules are found to play important roles. They significantly reduce relevant reaction barriers. Our work has also explored oxygenation reactions of NA with molecular oxygen and radical-radical dimerization reactions.
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Affiliation(s)
- Pin Xiao
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, China
| | - Qian Wang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, China
| | - Wei-Hai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, China
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, China
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29
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Ji T, Cui Z, Zhang W, Cao Y, Zhang Y, He SA, Xu M, Sun Y, Zou R, Hu J. UV and visible light synergetic photodegradation using rutile TiO2 nanorod arrays based on a p–n Junction. Dalton Trans 2017; 46:4296-4302. [DOI: 10.1039/c7dt00261k] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The enhanced photocatalytic performance of a TiO2-based multi-junction device is ascribed to a photovoltage generated in the junction, promoting the carriers separation.
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30
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Enami S, Colussi AJ. Efficient scavenging of Criegee intermediates on water by surface-active cis-pinonic acid. Phys Chem Chem Phys 2017. [DOI: 10.1039/c7cp03869k] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Criegee intermediates efficiently react with surface-active cis-pinonic acid rather than linear alkyl organic acids of similar size, or interfacial water molecules at air-aqueous interfaces.
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Affiliation(s)
- Shinichi Enami
- National Institute for Environmental Studies
- Tsukuba
- Japan
| | - A. J. Colussi
- Linde Center for Global Environmental Science
- California Institute of Technology
- USA
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31
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Enami S, Fujii T, Sakamoto Y, Hama T, Kajii Y. Carboxylate Ion Availability at the Air–Water Interface. J Phys Chem A 2016; 120:9224-9234. [DOI: 10.1021/acs.jpca.6b08868] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shinichi Enami
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Tomihide Fujii
- Graduate School of Global Environmental
Studies, Kyoto University, Kyoto 606-8501, Japan
| | - Yosuke Sakamoto
- Graduate School of Global Environmental
Studies, Kyoto University, Kyoto 606-8501, Japan
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8316, Japan
| | - Tetsuya Hama
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
| | - Yoshizumi Kajii
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
- Graduate School of Global Environmental
Studies, Kyoto University, Kyoto 606-8501, Japan
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8316, Japan
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32
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Enami S, Hoffmann MR, Colussi AJ. Halogen Radical Chemistry at Aqueous Interfaces. J Phys Chem A 2016; 120:6242-8. [DOI: 10.1021/acs.jpca.6b04219] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Shinichi Enami
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Michael R. Hoffmann
- Linde
Center for Global Environmental Science, California Institute of Technology, Pasadena, California 91125, United States
| | - A. J. Colussi
- Linde
Center for Global Environmental Science, California Institute of Technology, Pasadena, California 91125, United States
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