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Kenseth CM, Hafeman NJ, Rezgui SP, Chen J, Huang Y, Dalleska NF, Kjaergaard HG, Stoltz BM, Seinfeld JH, Wennberg PO. Particle-phase accretion forms dimer esters in pinene secondary organic aerosol. Science 2023; 382:787-792. [PMID: 37972156 DOI: 10.1126/science.adi0857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 10/11/2023] [Indexed: 11/19/2023]
Abstract
Secondary organic aerosol (SOA) is ubiquitous in the atmosphere and plays a pivotal role in climate, air quality, and health. The production of low-volatility dimeric compounds through accretion reactions is a key aspect of SOA formation. However, despite extensive study, the structures and thus the formation mechanisms of dimers in SOA remain largely uncharacterized. In this work, we elucidate the structures of several major dimer esters in SOA from ozonolysis of α-pinene and β-pinene-substantial global SOA sources-through independent synthesis of authentic standards. We show that these dimer esters are formed in the particle phase and propose a mechanism of nucleophilic addition of alcohols to a cyclic acylperoxyhemiacetal. This chemistry likely represents a general pathway to dimeric compounds in ambient SOA.
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Affiliation(s)
- Christopher M Kenseth
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Nicholas J Hafeman
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Samir P Rezgui
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jing Chen
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Yuanlong Huang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Nathan F Dalleska
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Henrik G Kjaergaard
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Brian M Stoltz
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - John H Seinfeld
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
| | - Paul O Wennberg
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125, USA
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2
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Bell DM, Pospisilova V, Lopez-Hilfiker F, Bertrand A, Xiao M, Zhou X, Huang W, Wang DS, Lee CP, Dommen J, Baltensperger U, Prevot ASH, El Haddad I, Slowik JG. Effect of OH scavengers on the chemical composition of α-pinene secondary organic aerosol. ENVIRONMENTAL SCIENCE: ATMOSPHERES 2023; 3:115-123. [PMID: 36743126 PMCID: PMC9850668 DOI: 10.1039/d2ea00105e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022]
Abstract
OH scavengers are extensively used in studies of secondary organic aerosol (SOA) because they create an idealized environment where only a single oxidation pathway is occurring. Here, we present a detailed molecular characterization of SOA produced from α-pinene + O3 with a variety of OH scavengers using the extractive electrospray time-of-flight mass spectrometer in our atmospheric simulation chamber, which is complemented by characterizing the gas phase composition in flow reactor experiments. Under our experimental conditions, radical chemistry largely controls the composition of SOA. Besides playing their desired role in suppressing the reaction of α-pinene with OH, OH scavengers alter the reaction pathways of radicals produced from α-pinene + O3. This involves changing the HO2 : RO2 ratio, the identity of the RO2 radicals present, and the RO2 major sinks. As a result, the use of the OH scavengers has significant effects on the composition of SOA, including inclusions of scavenger molecules in SOA, the promotion of fragmentation reactions, and depletion of dimers formed via α-pinene RO2-RO2 reactions. To date fragmentation reactions and inclusion of OH scavenger products into secondary organic aerosol have not been reported in atmospheric simulation chamber studies. Therefore, care should be considered if and when to use an OH scavenger during experiments.
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Affiliation(s)
- David M. Bell
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Veronika Pospisilova
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland,Tofwerk3600 ThunSwitzerland
| | - Felipe Lopez-Hilfiker
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland,Tofwerk3600 ThunSwitzerland
| | - Amelie Bertrand
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Mao Xiao
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Xueqin Zhou
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Wei Huang
- Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology76344 Eggenstein-LeopoldshafenGermany
| | - Dongyu S. Wang
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Chuan Ping Lee
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Josef Dommen
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Urs Baltensperger
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Andre S. H. Prevot
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Imad El Haddad
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
| | - Jay G. Slowik
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute5232 VilligenSwitzerland
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3
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Zhao Y, Yao M, Wang Y, Li Z, Wang S, Li C, Xiao H. Acylperoxy Radicals as Key Intermediates in the Formation of Dimeric Compounds in α-Pinene Secondary Organic Aerosol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:14249-14261. [PMID: 36178682 DOI: 10.1021/acs.est.2c02090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
High molecular weight dimeric compounds constitute a significant fraction of secondary organic aerosol (SOA) and have profound impacts on the properties and lifecycle of particles in the atmosphere. Although different formation mechanisms involving reactive intermediates and/or closed-shell monomeric species have been proposed for the particle-phase dimers, their relative importance remains in debate. Here, we report unambiguous experimental evidence of the important role of acyl organic peroxy radicals (RO2) and a small but non-negligible contribution from stabilized Criegee intermediates (SCIs) in the formation of particle-phase dimers during ozonolysis of α-pinene, one of the most important precursors for biogenic SOA. Specifically, we find that acyl RO2-involved reactions explain 50-80% of total oxygenated dimer signals (C15-C20, O/C ≥ 0.4) and 20-30% of the total less oxygenated (O/C < 0.4) dimer signals. In particular, they contribute to 70% of C15-C19 dimer ester formation, likely mainly via the decarboxylation of diacyl peroxides arising from acyl RO2 cross-reactions. In comparison, SCIs play a minor role in the formation of C15-C19 dimer esters but react noticeably with the most abundant C9 and C10 carboxylic acids and/or carbonyl products to form C19 and C20 dimeric peroxides, which are prone to particle-phase transformation to form more stable dimers without the peroxide functionality. This work provides a clearer view of the formation pathways of particle-phase dimers from α-pinene oxidation and would help reduce the uncertainties in future atmospheric modeling of the budget, properties, and health and climate impacts of SOA.
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Affiliation(s)
- Yue Zhao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Min Yao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yingqi Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ziyue Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shunyao Wang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chenxi Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Huayun Xiao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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4
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Agarwal A, Boruah PJ, Sarkar B, Paul AK. Post-Transition-State Direct Dynamics Simulations on the Ozonolysis of Catechol. J Phys Chem A 2022; 126:5314-5327. [PMID: 35943451 DOI: 10.1021/acs.jpca.2c04028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
On-the-fly dynamics simulations are performed for the reaction of catechol + O3. The post transition state (TS) dynamics is studied at temperatures of 400 and 500 K. The PM7 semiempirical method is employed for calculating the potential energy gradient needed for integrating Hamilton's equations of motion. This semiempirical method provides excellent agreement in terms of energy and geometry of the TSs as well as minimum energy states of the system with respect to B3LYP/6-311+G (2df, 2p) calculated results. In the dynamics, first, a peroxyacid is formed, which further dissociates to different fragments. Four major channels forming CO, CO2, H2O, and small carboxylic acid (SCA) fragments are seen in this reaction. Rates of each of the channels and the overall unimolecular reaction are calculated at both temperatures. Branching ratios of all these product channels are calculated and compared with experiment. The minimum energy profile of CO2, CO, and H2O channels are calculated. A qualitative estimate of activation energies for all the channels are obtained and compared with the explicit TS energies of three product channels, which ultimately correlate with the reaction probabilities.
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Affiliation(s)
- Ankita Agarwal
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India
| | - Palash Jyoti Boruah
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India
| | - Biplab Sarkar
- Department of Chemistry, North Eastern Hill University, Shillong 793003, Meghalaya, India
| | - Amit K Paul
- Department of Chemistry, National Institute of Technology Meghalaya, Shillong 793003, Meghalaya, India
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5
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Wang W, Wang X, Lakey PSJ, Ezell MJ, Shiraiwa M, Finlayson-Pitts BJ. Gas Phase and Gas-Solid Interface Ozonolysis of Nitrogen Containing Alkenes: Nitroalkenes, Enamines, and Nitroenamines. J Phys Chem A 2022; 126:5398-5406. [PMID: 35925795 PMCID: PMC9393864 DOI: 10.1021/acs.jpca.2c04400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Emerging contaminants are of concern due to their rapidly increasing numbers and potential ecological and human health effects. In this study, the synergistic effects of the presence of multifunctional nitro, amino and carbon-carbon double bond (C═C) groups on the gas phase ozonolysis in O2 or at the air/solid interface were investigated using five simple model compounds. The gas phase ozonolysis rate constants at 296 K were (3.5 ± 0.9) × 10-20 cm3 molecule-1 s-1 for 2-methyl-1-nitroprop-1-ene and (6.8 ± 0.8) × 10-19 cm3 molecule-1 s-1 for 4-methyl-4-nitro-1-pentene, with lifetimes of 134 and 7 days in the presence of 100 ppb ozone in the atmosphere, respectively. The rate constants for gas phase E-N,N-dimethyl-1-propenylamine and N,N-dimethylallylamine reactions with ozone were too fast (>10-18 cm3 molecule-1 s-1) to be measured, implying lifetimes of less than 5 days. A multiphase kinetics model (KM-GAP) was used to probe the gas-solid kinetics of 1-dimethylamino-2-nitroethylene, yielding a rate constant for the surface reaction of 1.8 × 10-9 cm2 molecule-1 s-1 and in the bulk 1× 10-16 cm3 molecule-1 s-1. These results show that a nitro group attached to the C═C lowers the gas phase rate constant by 2-3 orders of magnitude compared to the simple alkenes, while amino groups have the opposite effect. The presence of both groups provides counterbalancing effects. Products with deleterious health effects including dimethylformamide and formaldehyde were identified by FTIR. The identified products differentiate whether the initial site of ozone attack is C═C and/or the amino group. This study provides a basis for predicting the environmental fates of emerging contaminants and shows that both the toxicity of both the parent compounds and the products should be taken into account in assessing their environmental impacts.
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Affiliation(s)
- Weihong Wang
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Xinke Wang
- 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
| | - Michael J Ezell
- 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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6
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Peng W, Le C, Porter WC, Cocker DR. Variability in Aromatic Aerosol Yields under Very Low NO x Conditions at Different HO 2/RO 2 Regimes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:750-760. [PMID: 34978436 DOI: 10.1021/acs.est.1c04392] [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: 06/14/2023]
Abstract
Current chemical transport models generally use a constant secondary organic aerosol (SOA) yield to represent SOA formation from aromatic compounds under low NOx conditions. However, a wide range of SOA yields (10 to 42%) from m-xylene under low NOx conditions is observed in this study. The chamber HO2/RO2 ratio is identified as a key factor explaining SOA yield variability: higher SOA yields are observed for runs with a higher HO2/RO2 ratio. The RO2 + RO2 pathway, which can be increasingly significant under low NOx and HO2/RO2 conditions, shows a lower SOA-forming potential compared to the RO2 + HO2 pathway. While the traditional low-NOx chamber experiments are commonly used to represent the RO2 + HO2 pathway, this study finds that the impacts of the RO2 + RO2 pathway cannot be ignored under certain conditions. We provide guidance on how to best control for these two pathways in conducting chamber experiments to best obtain SOA yield curves and quantify the contributions from each pathway. On the global scale, the chemical transport model GEOS-Chem is used to identify regions characterized by lower surface HO2/RO2 ratios, suggesting that the RO2 + RO2 pathway is more likely to prove significant to overall SOA yields in those regions. Current models generally do not consider the RO2 + RO2 impacts on aromatic SOA formation, but preliminary sensitivity tests with updated SOA yield parameters based on such a pathway suggest that without this consideration, some types of SOA may be overestimated in regions with lower HO2/RO2 ratios.
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Affiliation(s)
- Weihan Peng
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, Riverside, California 92507, United States
- Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, Riverside, 1084 Columbia Avenue, Riverside, California 92507, United States
| | - Chen Le
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, Riverside, California 92507, United States
- Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, Riverside, 1084 Columbia Avenue, Riverside, California 92507, United States
| | - William C Porter
- Department of Environmental Sciences, University of California, Riverside, Riverside, California 92521, United States
| | - David R Cocker
- Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, Riverside, California 92507, United States
- Bourns College of Engineering, Center for Environmental Research and Technology (CE-CERT), University of California, Riverside, 1084 Columbia Avenue, Riverside, California 92507, United States
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7
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Wang Y, Zhu S, Ma J, Shen J, Wang P, Wang P, Zhang H. Enhanced atmospheric oxidation capacity and associated ozone increases during COVID-19 lockdown in the Yangtze River Delta. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 768:144796. [PMID: 33429116 PMCID: PMC7787908 DOI: 10.1016/j.scitotenv.2020.144796] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/19/2020] [Accepted: 12/20/2020] [Indexed: 05/22/2023]
Abstract
Aggressive air pollution control in China since 2013 has achieved sharp decreases in fine particulate matter (PM2.5), along with increased ozone (O3) concentrations. Due to the pandemic of coronavirus disease 2019 (COVID-19), China imposed nationwide restriction, leading to large reductions in economic activities and associated emissions. In particular, large decreases were found in nitrogen oxides (NOx) emissions (>50%) from transportation. However, O3 increased in the Yangtze River Delta (YRD), which cannot be fully explained by changes in NOx and volatile organic compound (VOCs) emissions. In this study, the Community Multi-scale Air Quality model was used to investigate O3 increase in the YRD. Our results show a significant increase of atmospheric oxidation capacity (AOC) indicated by enhanced oxidants levels (up to +25%) especially in southern Jiangsu, Shanghai and northern Zhejiang, inducing the elevated O3 during lockdown. Moreover, net P(HOx) of 0.4 to 1.6 ppb h-1 during lockdown (Case 2) was larger than the case without lockdown (Case 1), mainly resulting in the enhanced AOC and higher O3 production rate (+12%). This comprehensive analysis improves our understanding on AOC and associated O3 formation, which helps to design effective strategies to control O3.
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Affiliation(s)
- Yu Wang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Shengqiang Zhu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Jinlong Ma
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Juanyong Shen
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Pengfei Wang
- Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Peng Wang
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong 99907, China.
| | - Hongliang Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China; Institute of Eco-Chongming (IEC), Shanghai 200062, China.
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8
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Liu S, Jiang X, Tsona NT, Lv C, Du L. Effects of NOx, SO 2 and RH on the SOA formation from cyclohexene photooxidation. CHEMOSPHERE 2019; 216:794-804. [PMID: 30396140 DOI: 10.1016/j.chemosphere.2018.10.180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/06/2018] [Accepted: 10/26/2018] [Indexed: 06/08/2023]
Abstract
We performed a laboratory investigation of the secondary organic aerosol (SOA) formation from cyclohexene photooxidation with different initial NOx and SO2 concentrations at low and high relative humidity (RH). Both SOA yield and number concentration first increase drastically and then, decreased when the [VOC]0/[NOx]0 ratio changed from 30 to 10 and from 10 to 3. Though the presence of SO2 could increase the SOA number concentration, the SOA yield could only increase under [VOC]0/[NOx]0 = 10 and high RH, and [VOC]0/[NOx]0 = 3 and low RH experimental conditions, while decreasing under [VOC]0/[NOx]0 = 10 and low RH conditions. In the presence of SO2, the high RH and high NOx conditions were keys to efficient sulfate formation and could promote the SOA formation. The chemical composition of SOA was characterized using hybrid quadrupole-orbitrap mass spectrometer equipped with electrospray ionization (ESI-Q-Orbitrap-HRMS), and few organosulfates were identified. A visible enhancement of organosulfates and the formation of high molecular weight organic compounds were observed at high RH conditions, and this seemed to be the reason for the SOA yield increase at high RH.
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Affiliation(s)
- Shijie Liu
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Xiaotong Jiang
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Narcisse T Tsona
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Chen Lv
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Lin Du
- Environment Research Institute, Shandong University, Qingdao, 266237, China.
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9
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Rissanen MP, Kurtén T, Sipilä M, Thornton JA, Kangasluoma J, Sarnela N, Junninen H, Jørgensen S, Schallhart S, Kajos MK, Taipale R, Springer M, Mentel TF, Ruuskanen T, Petäjä T, Worsnop DR, Kjaergaard HG, Ehn M. The formation of highly oxidized multifunctional products in the ozonolysis of cyclohexene. J Am Chem Soc 2014; 136:15596-606. [PMID: 25283472 DOI: 10.1021/ja507146s] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The prompt formation of highly oxidized organic compounds in the ozonolysis of cyclohexene (C6H10) was investigated by means of laboratory experiments together with quantum chemical calculations. The experiments were performed in borosilicate glass flow tube reactors coupled to a chemical ionization atmospheric pressure interface time-of-flight mass spectrometer with a nitrate ion (NO3(-))-based ionization scheme. Quantum chemical calculations were performed at the CCSD(T)-F12a/VDZ-F12//ωB97XD/aug-cc-pVTZ level, with kinetic modeling using multiconformer transition state theory, including Eckart tunneling corrections. The complementary investigation methods gave a consistent picture of a formation mechanism advancing by peroxy radical (RO2) isomerization through intramolecular hydrogen shift reactions, followed by sequential O2 addition steps, that is, RO2 autoxidation, on a time scale of seconds. Dimerization of the peroxy radicals by recombination and cross-combination reactions is in competition with the formation of highly oxidized monomer species and is observed to lead to peroxides, potentially diacyl peroxides. The molar yield of these highly oxidized products (having O/C > 1 in monomers and O/C > 0.55 in dimers) from cyclohexene ozonolysis was determined as (4.5 ± 3.8)%. Fully deuterated cyclohexene and cis-6-nonenal ozonolysis, as well as the influence of water addition to the system (either H2O or D2O), were also investigated in order to strengthen the arguments on the proposed mechanism. Deuterated cyclohexene ozonolysis resulted in a less oxidized product distribution with a lower yield of highly oxygenated products and cis-6-nonenal ozonolysis generated the same monomer product distribution, consistent with the proposed mechanism and in agreement with quantum chemical modeling.
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Affiliation(s)
- Matti P Rissanen
- Department of Physics, University of Helsinki , P.O. Box 64, Helsinki, 00014, Finland
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10
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Emanuelsson EU, Watne ÅK, Lutz A, Ljungström E, Hallquist M. Influence of Humidity, Temperature, and Radicals on the Formation and Thermal Properties of Secondary Organic Aerosol (SOA) from Ozonolysis of β-Pinene. J Phys Chem A 2013; 117:10346-58. [DOI: 10.1021/jp4010218] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Eva U. Emanuelsson
- Atmospheric Science, Department
of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Ågot K. Watne
- Atmospheric Science, Department
of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Anna Lutz
- Atmospheric Science, Department
of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Evert Ljungström
- Atmospheric Science, Department
of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Mattias Hallquist
- Atmospheric Science, Department
of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
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11
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Pathak RK, Salo K, Emanuelsson EU, Cai C, Lutz A, Hallquist AM, Hallquist M. Influence of ozone and radical chemistry on limonene organic aerosol production and thermal characteristics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:11660-11669. [PMID: 22985264 DOI: 10.1021/es301750r] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Limonene has a strong tendency to form secondary organic aerosol (SOA) in the atmosphere and in indoor environments. Initial oxidation occurs mainly via ozone or OH radical chemistry. We studied the effect of O(3) concentrations with or without a OH radical scavenger (2-butanol) on the SOA mass and thermal characteristics using the Gothenburg Flow Reactor for Oxidation Studies at Low Temperatures and a volatility tandem differential mobility analyzer. The SOA mass using 15 ppb limonene was strongly dependent on O(3) concentrations and the presence of a scavenger. The SOA volatility in the presence of a scavenger decreased with increasing levels of O(3), whereas without a scavenger, there was no significant change. A chemical kinetic model was developed to simulate the observations using vapor pressure estimates for compounds that potentially contributed to SOA. The model showed that the product distribution was affected by changes in both OH and ozone concentrations, which partly explained the observed changes in volatility, but was strongly dependent on accurate vapor pressure estimation methods. The model-experiment comparison indicated a need to consider organic peroxides as important SOA constituents. The experimental findings could be explained by secondary condensed-phase ozone chemistry, which competes with OH radicals for the oxidation of primary unsaturated products.
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Affiliation(s)
- Ravi K Pathak
- Atmospheric Science, Department of Chemistry and Molecular Biology, University of Gothenburg, S-412 96 Gothenburg, Sweden
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12
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Bernard F, Daële V, Mellouki A, Sidebottom H. Studies of the Gas Phase Reactions of Linalool, 6-Methyl-5-hepten-2-ol and 3-Methyl-1-penten-3-ol with O3 and OH Radicals. J Phys Chem A 2012; 116:6113-26. [DOI: 10.1021/jp211355d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- François Bernard
- ICARE-CNRS and OSUC, 1C
Avenue de la Recherche Scientifique, 45071 cedex 02 Orléans,
France
| | - Véronique Daële
- ICARE-CNRS and OSUC, 1C
Avenue de la Recherche Scientifique, 45071 cedex 02 Orléans,
France
| | - Abdelwahid Mellouki
- ICARE-CNRS and OSUC, 1C
Avenue de la Recherche Scientifique, 45071 cedex 02 Orléans,
France
| | - Howard Sidebottom
- School
of Chemistry and Chemical Biology, University College Dublin, Dublin, Ireland
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13
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Carlsson PTM, Dege JE, Keunecke C, Krüger BC, Wolf JL, Zeuch T. Pressure dependent aerosol formation from the cyclohexene gas-phase ozonolysis in the presence and absence of sulfur dioxide: a new perspective on the stabilisation of the initial clusters. Phys Chem Chem Phys 2012; 14:11695-705. [DOI: 10.1039/c2cp40714k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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14
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15
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Bothe M, Donahue NM. Organic aerosol formation in citronella candle plumes. AIR QUALITY, ATMOSPHERE, & HEALTH 2010; 3:131-137. [PMID: 20700379 PMCID: PMC2914284 DOI: 10.1007/s11869-009-0061-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Accepted: 12/21/2009] [Indexed: 05/29/2023]
Abstract
Citronella candles are widely used as insect repellants, especially outdoors in the evening. Because these essential oils are unsaturated, they have a unique potential to form secondary organic aerosol (SOA) via reaction with ozone, which is also commonly elevated on summer evenings when the candles are often in use. We investigated this process, along with primary aerosol emissions, by briefly placing a citronella tealight candle in a smog chamber and then adding ozone to the chamber. In repeated experiments, we observed rapid and substantial SOA formation after ozone addition; this process must therefore be considered when assessing the risks and benefits of using citronella candle to repel insects.
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Affiliation(s)
- Melanie Bothe
- Department of Biochemical and Chemical Engineering, Technische Universität Dortmund, Dortmund, Germany
| | - Neil McPherson Donahue
- Carnegie Mellon University Center for Atmospheric Particle Studies, 5000 Forbes Ave, Pittsburgh, PA 15213 USA
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16
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Connelly BM, Tolbert MA. Reaction of isoprene on thin sulfuric acid films: kinetics, uptake, and product analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:4603-4608. [PMID: 20499904 DOI: 10.1021/es100708b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A high vacuum Knudsen flow reactor was used to determine the reactive uptake coefficient, gamma, of isoprene on sulfuric acid films as a function of sulfuric acid weight percent, temperature, and relative humidity. No discernible dependence was observed for gamma over the range of temperatures (220 - 265 K) and pressures (10(-7) Torr -10(-4) Torr) studied. However, the uptake coefficient increased with increased sulfuric acid concentration between the range of 78 wt % (gamma(i) approximately 10(-4)) and 93 wt % (gamma(i) approximately 10(-3)). In addition to the Knudsen Cell, a bulk study was conducted between 60 and 85 wt % H(2)SO(4) to quantify uptake at lower acid concentrations and to determine reaction products. After exposing sulfuric acid to gaseous isoprene the condensed phase products were extracted and analyzed using gas chromatography/mass spectrometry (GC/MS). Isoprene was observed to polymerize in the sulfuric acid and form yellow/red colored monoterpenes and cyclic sesquiterpenes. Finally, addition of water to the 85 wt % sulfuric acid/isoprene product mixture released these terpenes from the condensed phase into the gas phase. Together these experiments imply that direct isoprene uptake will not produce significant SOA; however, terpene production from the small uptake may be relevant for ultrafine particles and could affect growth and nucleation.
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Affiliation(s)
- Brandon M Connelly
- The Cooperative Institute for Research in Environmental Sciences, The Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0216, USA
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17
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Jonsson AM, Hallquist M, Ljungström E. Influence of OH scavenger on the water effect on secondary organic aerosol formation from ozonolysis of limonene, Delta3-carene, and alpha-pinene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:5938-5944. [PMID: 18767648 DOI: 10.1021/es702508y] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The effect of OH scavengers on how water vapor influences the formation of secondary organic aerosol (SOA) in ozonolysis of limonene, Delta3-carene, and alpha-pinene at low concentrations has been investigated by using a laminar flow reactor. Cyclohexane and 2-butanol (3-40 x 10(13) molecules cm(-3)) were used as scavengers and compared to experiments without any scavenger. The reactions were conducted at 298 K and at relative humidities between <10 and 80%. The yield of SOA decreased in the order "no scavenger" > 2-butanol > cyclohexane. The effect of water vapor was similar for 2-butanol and without a scavenger, with an increase in particle number and mass concentration with increasing relative humidity. The water effect for cyclohexane was more complex, depending on the terpene, scavenger concentration, and SOA concentration. The water effect seems to be influenced by the HO2/RO2 ratio. The results are discussed in relation to the currently suggested mechanism for alkene ozonolysis and to atmospheric importance. The results imply that the ozone-initiated oxidation of terpenes needs revision in order to fully account for the role of water in the chemical mechanism.
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Affiliation(s)
- Asa M Jonsson
- Department of Chemistry, Atmospheric Science, University of Gothenburg, SE-412 96 Göteborg, Sweden.
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18
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Xia AG, Michelangeli DV, Makar PA. Box model studies of the secondary organic aerosol formation under different HC/NOxconditions using the subset of the Master Chemical Mechanism forα-pinene oxidation. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd008726] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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19
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Ma Y, Marston G. Multifunctional acid formation from the gas-phase ozonolysis of β-pinene. Phys Chem Chem Phys 2008; 10:6115-26. [DOI: 10.1039/b807863g] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Ma Y, Russell AT, Marston G. Mechanisms for the formation of secondary organic aerosol components from the gas-phase ozonolysis of α-pinene. Phys Chem Chem Phys 2008; 10:4294-312. [DOI: 10.1039/b803283a] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Burkholder JB, Baynard T, Ravishankara AR, Lovejoy ER. Particle nucleation following the O3
and OH initiated oxidation of α
-pinene and β
-pinene between 278 and 320 K. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007783] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- James B. Burkholder
- Earth System Research Laboratory, Chemical Sciences Division; National Oceanic and Atmospheric Administration; Boulder Colorado USA
| | - Tahllee Baynard
- Earth System Research Laboratory, Chemical Sciences Division; National Oceanic and Atmospheric Administration; Boulder Colorado USA
- Cooperative Institute for Research in Environmental Sciences; University of Colorado; Boulder Colorado USA
| | - A. R. Ravishankara
- Earth System Research Laboratory, Chemical Sciences Division; National Oceanic and Atmospheric Administration; Boulder Colorado USA
| | - Edward R. Lovejoy
- Earth System Research Laboratory, Chemical Sciences Division; National Oceanic and Atmospheric Administration; Boulder Colorado USA
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22
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Donahue NM, Tischuk JE, Marquis BJ, Huff Hartz KE. Secondary organic aerosol from limona ketone: insights into terpene ozonolysis via synthesis of key intermediates. Phys Chem Chem Phys 2007; 9:2991-8. [PMID: 17551623 DOI: 10.1039/b701333g] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Limona ketone was synthesized to explore the secondary organic aerosol (SOA) formation mechanism from limonene ozonolysis and also to test group-additivity concepts describing the volatility distribution of ozonolysis products from similar precursors. Limona ketone SOA production is indistinguishable from alpha-pinene, confirming the expected similarity. However, limona ketone SOA production is significantly less intense than limonene SOA production. The very low vapor pressure of limonene ozonolysis products is consistent with full oxidation of both double bonds in limonene and furthermore with production of products other than ketones after oxidation of the exo double bond in limonene. Mass-balance constraints confirm that ketone products from exo double-bond ozonolysis have a minimal contribution to the ultimate product yield. These results serve as the foundation for an emerging framework to describe the effect on volatility of successive generations of organic compounds in the atmosphere.
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Affiliation(s)
- Neil M Donahue
- Center for Atmospheric Particle Studies, Carnegie Mellon University, USA
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23
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Zhang J, Huff Hartz KE, Pandis SN, Donahue NM. Secondary Organic Aerosol Formation from Limonene Ozonolysis: Homogeneous and Heterogeneous Influences as a Function of NOx. J Phys Chem A 2006; 110:11053-63. [PMID: 16986838 DOI: 10.1021/jp062836f] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Limonene has a high emission rate both from biogenic sources and from household solvents. Here we examine the limonene + ozone reaction as a source for secondary organic aerosol (SOA). Our data show that limonene has very high potential to form SOA and that NO(x) levels, O(3) levels, and UV radiation all influence SOA formation. High SOA formation is observed under conditions where both double bonds in limonene are oxidized, but those conditions depend strongly on NO(x). At low NO(x), heterogeneous oxidation of the terminal double bond follows the initial limonene ozonolysis (at the endocyclic double bond) almost immediately, making the initial reaction rate limiting. This requires a high uptake coefficient between ozone and the first-generation, unsaturated organic particles. However, at high NO(x), this heterogeneous processing is inhibited and gas-phase oxidation of the terminal double bond dominates. Although this chemistry is slower, it also yields products with low volatility. UV light suppresses production of the lowest volatility products, as we have shown in earlier studies of the alpha-pinene + ozone reaction.
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Affiliation(s)
- Jieyuan Zhang
- Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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24
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Lee A, Goldstein AH, Keywood MD, Gao S, Varutbangkul V, Bahreini R, Ng NL, Flagan RC, Seinfeld JH. Gas-phase products and secondary aerosol yields from the ozonolysis of ten different terpenes. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006437] [Citation(s) in RCA: 191] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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25
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Sato K. Chemical Compositions of Secondary Organic Aerosol from the Ozonolysis of Cyclohexene in the Absence of Seed Particles. CHEM LETT 2005. [DOI: 10.1246/cl.2005.1584] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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26
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Presto AA, Hartz KEH, Donahue NM. Secondary organic aerosol production from terpene ozonolysis. 2. Effect of NOx concentration. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:7046-54. [PMID: 16201628 DOI: 10.1021/es050400s] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We report secondary organic aerosol (SOA) yields from the ozonolysis of alpha-pinene in the presence of NO and NO2. Experimental conditions are characterized by the [VOC]0/ [NOx]0 ratio (ppbC/ppb), which varies from approximately 1 to approximately 300. SOA yield is constant for [VOC]0/[NOx]0 > approximately 15 and decreases dramatically (by more than a factor of 4) as [VOC]0/[NOx]0 decreases. Aerosol production is completely suppressed in the presence of NO for [VOC]0/[NOx]0 < or = 4.5. Fouriertransform IR analysis of filter samples reveals that nitrate-containing species contribute significantly to the total aerosol mass at low [VOC]0/[NOx]0. Yield reduction is a result of the formation of a more volatile product distribution as [VOC]0/[NOx]0 decreases; we propose that the change in the product distribution is driven by changes in the gas-phase chemistry as NOx concentration increases. We also present two-product model parameters to describe aerosol production from the alpha-pinene/0/NOx system under both high- and low-NOx conditions.
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Affiliation(s)
- Albert A Presto
- Department of Chemistry and Department of Chemical Engineering, Doherty Hall, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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27
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Huff Hartz KE, Rosenørn T, Ferchak SR, Raymond TM, Bilde M, Donahue NM, Pandis SN. Cloud condensation nuclei activation of monoterpene and sesquiterpene secondary organic aerosol. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jd005754] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Kara E. Huff Hartz
- Department of Chemical Engineering; Carnegie Mellon University; Pittsburgh Pennsylvania USA
| | - Thomas Rosenørn
- Department of Chemistry; University of Copenhagen; Copenhagen Denmark
| | - Shaun R. Ferchak
- Department of Chemical Engineering; Carnegie Mellon University; Pittsburgh Pennsylvania USA
| | - Timothy M. Raymond
- Department of Chemical Engineering; Bucknell University; Lewisburg Pennsylvania USA
| | - Merete Bilde
- Department of Chemistry; University of Copenhagen; Copenhagen Denmark
| | - Neil M. Donahue
- Department of Chemical Engineering; Carnegie Mellon University; Pittsburgh Pennsylvania USA
| | - Spyros N. Pandis
- Department of Chemical Engineering; Carnegie Mellon University; Pittsburgh Pennsylvania USA
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28
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Donahue NM, Hartz KEH, Chuong B, Presto AA, Stanier CO, Rosenhørn T, Robinson AL, Pandis SN. Critical factors determining the variation in SOA yields from terpene ozonolysis: A combined experimental and computational study. Faraday Discuss 2005; 130:295-309; discussion 363-86, 519-24. [PMID: 16161790 DOI: 10.1039/b417369d] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A substantial fraction of the total ultrafine particulate mass is comprised of organic compounds. Of this fraction, a significant subfraction is secondary organic aerosol (SOA), meaning that the compounds are a by-product of chemistry in the atmosphere. However, our understanding of the kinetics and mechanisms leading to and following SOA formation is in its infancy. We lack a clear description of critical phenomena; we often don't know the key, rate limiting steps in SOA formation mechanisms. We know almost nothing about aerosol yields past the first generation of oxidation products. Most importantly, we know very little about the derivatives in these mechanisms; we do not understand how changing conditions, be they precursor levels, oxidant concentrations, co-reagent concentrations (i.e., the VOC/NOx ratio) or temperature will influence the yields of SOA. In this paper we explore the connections between fundamental details of physical chemistry and the multitude of steps associated with SOA formation, including the initial gas-phase reaction mechanisms leading to condensible products, the phase partitioning itself, and the continued oxidation of the condensed-phase organic products. We show that SOA yields in the alpha-pinene + ozone are highly sensitive to NOx, and that SOA yields from beta-caryophylene + ozone appear to increase with continued ozone exposure, even as aerosol hygroscopicity increases as well. We suggest that SOA yields are likely to increase substantially through several generations of oxidative processing of the semi-volatile products.
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Affiliation(s)
- Neil M Donahue
- Department of Chemistry and Chemical Engineering, Carnegie Mellon University, Pittsburgh PA 15213, USA.
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29
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Iinuma Y, Böge O, Miao Y, Sierau B, Gnauk T, Herrmann H. Laboratory studies on secondary organic aerosol formation from terpenes. Faraday Discuss 2005; 130:279-94; discussion 363-86, 519-24. [PMID: 16161789 DOI: 10.1039/b502160j] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of secondary organic aerosol (SOA) following the ozonolysis of terpene has been investigated intensively in recent years. The enhancement of SOA yields from the acid catalysed reactions of organics on aerosol surfaces or in the bulk particle phase has been receiving great attention. Recent studies show that the presence of acidic seed particles increases the SOA yield significantly (M. S. Jang and R. M. Kamens, Environ. Sci. Technol., 2001, 35, 4758, ref. 1; M. S. Jang, N. M. Czoschke, S. Lee and R. M. Kamens, Science, 2002, 298, 814, ref. 2; N. M. Czoschke, M. Jang and R. M. Kamens, Atmos. Environ., 2003, 37, 4287, ref. 3; M. S. Jang, B. Carroll, B. Chandramouli and R. M. Kamens, Environ. Sci. Technol., 2003, 37, 3828, ref. 4; Y. Iinuma, O. Böge, T. Gnauk and H. Herrmann, Atmos. Environ., 2004, 38, 761, ref. 5; S. Gao, M. Keywood, N. L. Ng, J. Surratt, V. Varutbangkul, R. Bahreini, R. C. Flagan and J. H. Seinfeld, J. Phys. Chem. A, 2004, 108, 10147, ref. 6). More detailed studies report the formation of higher molecular weight products in SOA (refs. 5 and 6; M. P. Tolocka, M. Jang, J. M. Ginter, F. J. Cox, R. M. Kamens and M. V. Johnston, Environ. Sci. Technol., 2004, 38, 1428, ref. 7; S. Gao, N. L. Ng, M. Keywood, V. Varutbangkul, R. Bahreini, A. Nenes, J. He, K. Y. Yoo, J. L. Beauchamp, R. P. Hodyss, R. C. Flagan and J. H. Seinfeld, Environ. Sci. Technol., 2004, 38, 6582, ref. 8) which could result in a non-reversible uptake of organics into the particle phase. Most of the past studies concentrated on the characterisation of the yields of enhanced SOA and its composition from ozonolysis of terpenes in the presence or absence of acidic and neutral seed particles. Recent findings from cyclohexene ozonolysis show that the presence of OH scavengers can also significantly influence the SOA yield. Our new results from the IfT chemistry department aerosol chamber on terpene ozonolysis in the presence of OH scavengers show that the presence of hydroxyl radical scavengers clearly reduces the amount of formed SOA. The OH scavenger strongly depletes the formation of oligomeric compounds in the particle phase in contrast to previous findings (M. D. Keywood, J. H. Kroll, V. Varatbangkul, R. Bahreini, R. C. Flagan and J. H. Seinfeld, Environ. Sci. Technol., 2004, 38, 3343, ref. 9). This result indicates that hydroxyl radicals play an important role in the formation of precursor compounds (e.g., hydroxy pinonaldehyde) for the particle phase heterogeneous acid catalysed reactions leading to the higher molecular weight compounds and thus the enhancement of SOA yields. Better understanding of the role of hydroxyl radicals in the formation of SOA is necessary to distinguish between the contribution of ozonolysis and hydroxyl radicals to the SOA yield. If the recent findings are a ubiquitous phenomenon in the atmosphere, current atmospheric and climate models might underestimate SOA formation yields, particle phase OC contents and its impact on the atmospheric radiation budget.
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Affiliation(s)
- Yoshiteru Iinuma
- Leibniz-Institut für Troposphärenforschung, Permoserstr. 15, D-04318 Leipzig, Germany
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30
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Gao S, Keywood M, Ng NL, Surratt J, Varutbangkul V, Bahreini R, Flagan RC, Seinfeld JH. Low-Molecular-Weight and Oligomeric Components in Secondary Organic Aerosol from the Ozonolysis of Cycloalkenes and α-Pinene. J Phys Chem A 2004. [DOI: 10.1021/jp047466e] [Citation(s) in RCA: 249] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Song Gao
- Departments of Environmental Science and Engineering and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Melita Keywood
- Departments of Environmental Science and Engineering and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Nga L. Ng
- Departments of Environmental Science and Engineering and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Jason Surratt
- Departments of Environmental Science and Engineering and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Varuntida Varutbangkul
- Departments of Environmental Science and Engineering and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Roya Bahreini
- Departments of Environmental Science and Engineering and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Richard C. Flagan
- Departments of Environmental Science and Engineering and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - John H. Seinfeld
- Departments of Environmental Science and Engineering and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
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