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Prophet AM, Polley K, Van Berkel GJ, Limmer DT, Wilson KR. Iodide oxidation by ozone at the surface of aqueous microdroplets. Chem Sci 2024; 15:736-756. [PMID: 38179528 PMCID: PMC10762724 DOI: 10.1039/d3sc04254e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 12/03/2023] [Indexed: 01/06/2024] Open
Abstract
The oxidation of iodide by ozone occurs at the sea-surface and within sea spray aerosol, influencing the overall ozone budget in the marine boundary layer and leading to the emission of reactive halogen gases. A detailed account of the surface mechanism has proven elusive, however, due to the difficulty in quantifying multiphase kinetics. To obtain a clearer understanding of this reaction mechanism at the air-water interface, we report pH-dependent oxidation kinetics of I- in single levitated microdroplets as a function of [O3] using a quadrupole electrodynamic trap and an open port sampling interface for mass spectrometry. A kinetic model, constrained by molecular simulations of O3 dynamics at the air-water interface, is used to understand the coupled diffusive, reactive, and evaporative pathways at the microdroplet surface, which exhibit a strong dependence on bulk solution pH. Under acidic conditions, the surface reaction is limited by O3 diffusion in the gas phase, whereas under basic conditions the reaction becomes rate limited on the surface. The pH dependence also suggests the existence of a reactive intermediate IOOO- as has previously been observed in the Br- + O3 reaction. Expressions for steady-state surface concentrations of reactants are derived and utilized to directly compute uptake coefficients for this system, allowing for an exploration of uptake dependence on reactant concentration. In the present experiments, reactive uptake coefficients of O3 scale weakly with bulk solution pH, increasing from 4 × 10-4 to 2 × 10-3 with decreasing solution pH from pH 13 to pH 3.
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Affiliation(s)
- Alexander M Prophet
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
- Department of Chemistry, University of California Berkeley CA 94720 USA
| | - Kritanjan Polley
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
- Department of Chemistry, University of California Berkeley CA 94720 USA
| | | | - David T Limmer
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
- Department of Chemistry, University of California Berkeley CA 94720 USA
- Materials Science Division, Lawrence Berkeley National Laboratory Berkeley California 94720 USA
- Kavli Energy NanoScience Institute Berkeley California 94720 USA
| | - Kevin R Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
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2
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Schneider SR, Lakey PSJ, Shiraiwa M, Abbatt JPD. Iodine emission from the reactive uptake of ozone to simulated seawater. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:254-263. [PMID: 35838601 DOI: 10.1039/d2em00111j] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The heterogeneous reaction of ozone and iodide is both an important source of atmospheric iodine and dry deposition pathway of ozone in marine environments. While the iodine generated from this reaction is primarily in the form of HOI and I2, there is also evidence of volatile organoiodide compound emissions in the presence of organics without biological activity occuring [M. Martino, G. P. Mills, J. Woeltjen and P. S. Liss, A new source of volatile organoiodine compounds in surface seawater, Geophys. Res. Lett., 2009, 36, L01609, L. Tinel, T. J. Adams, L. D. J. Hollis, A. J. M. Bridger, R. J. Chance, M. W. Ward, S. M. Ball and L. J. Carpenter, Influence of the Sea Surface Microlayer on Oceanic Iodine Emissions, Environ. Sci. Technol., 2020, 54, 13228-13237]. In this study, we evaluate our fundamental understanding of the ozonolysis of iodide which leads to gas-phase iodine emissions. To do this, we compare experimental measurements of ozone-driven gas-phase I2 formation in a flow tube to predictions made with the kinetic multilayer model for surface and bulk chemistry (KM-SUB). The KM-SUB model uses literature rate coefficients used in current atmospheric chemistry models to predict I2(g) formation in pH-buffered solutions of marine composition containing chloride, bromide, and iodide compared to solutions containing only iodide. Experimentally, I2(g) formation was found to be suppressed in solutions containing seawater levels of chloride compared to solutions containing only iodide, but the model does not predict this effect using literature rate constants. However, the model is able to predict this trend upon adjustment of two specific reaction rate constants. To more closely represent true oceanic conditions, we add an organic component to the proxy seawater solutions using material generated from Thalassiosira pseudonana phytoplankton cultures. Whereas the rate of ozone deposition is unaffected, the formation rate of I2(g) is strongly suppressed in the presence of biological organic material, indicative of a sink or reduction of reactive iodine formed during the oxidation process.
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Affiliation(s)
- Stephanie R Schneider
- Department of Chemistry, University of Toronto, 80 St. George Street Toronto, Ontario, Canada.
| | - Pascale S J Lakey
- Department of Chemistry, University of California, Irvine 92697, California, USA
| | - Manabu Shiraiwa
- Department of Chemistry, University of California, Irvine 92697, California, USA
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, 80 St. George Street Toronto, Ontario, Canada.
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3
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Wilson KR, Prophet AM, Willis MD. A Kinetic Model for Predicting Trace Gas Uptake and Reaction. J Phys Chem A 2022; 126:7291-7308. [PMID: 36170058 DOI: 10.1021/acs.jpca.2c03559] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A model is developed to describe trace gas uptake and reaction with applications to aerosols and microdroplets. Gas uptake by the liquid is formulated as a coupled equilibria that links gas, surface, and bulk regions of the droplet or solution. Previously, this framework was used in explicit stochastic reaction-diffusion simulations to predict the reactive uptake kinetics of ozone with droplets containing aqueous aconitic acid, maleic acid, and sodium nitrite. With the use of prior data and simulation results, a new equation for the uptake coefficient is derived, which accounts for both surface and bulk reactions. Lambert W functions are used to obtain closed form solutions to the integrated rate laws for the multiphase kinetics; similar to previous expressions that describe Michaelis-Menten enzyme kinetics. Together these equations couple interface and bulk processes over a wide range of conditions and do not require many of the limiting assumptions needed to apply resistor model formulations to explain trace gas uptake and reaction.
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Affiliation(s)
- Kevin R Wilson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Alexander M Prophet
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.,Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Megan D Willis
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523 United States
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4
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Jiao X, Zeng R, Lan G, Zuo S, He J, Wang C. Mechanistic study on photochemical generation of I •/I 2•- radicals in coastal atmospheric aqueous aerosol. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 825:154080. [PMID: 35218835 DOI: 10.1016/j.scitotenv.2022.154080] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/27/2022] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
The reactive iodine species may exhibit significant impacts on many global atmospheric issues and the I•/I2•- radicals play key roles for inducing the formation of these reactive iodine species. However, the current understanding on the formation of I•/I2•- radicals in atmospheric aqueous aerosol is still quite limited. The results reported herein suggest that I•/I2•- can be produced simultaneously in aqueous aerosol by several sunlight-driven photochemical pathways including direct photo-dissociation of soluble organic iodine (SOI) at rates of 0.10-1.34 × 10-9 M ns-1 and 0.99-5.68 × 10-7 M μs-1, •OH-mediated oxidation of I- at 0.03-1.41 × 10-8 M ns-1 and 0.05-4.10 × 10-6 M μs-1, and 3DOM⁎-induced oxidation of I- at 1.57-1.65 × 10-9 M ns-1 and 0.99-5.68 × 10-7 M μs-1 for generation of I• and I2•-, respectively. Meanwhile, the pathway of eaq--initiated stepwise reduction of IO3- to I2(aq) and further photolyzed into I• plays negligible role in formation of I•/I2•- due to the low reaction rates and severe quenching effect of eaq- by dissolved O2. Our work presented the new data on mechanism and kinetics for comprehensive elucidation of I•/I2•- formation in coastal atmospheric aqueous aerosol and would help to better understand the transformation mechanism of iodine species, pathways of iodine cycling and the associated environmental impacts involving atmospheric reactive iodine radicals.
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Affiliation(s)
- Xiaoyu Jiao
- College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Rui Zeng
- College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Guangcai Lan
- College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Siyu Zuo
- College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan 430074, China
| | - Jun He
- Department of Chemical and Environmental Engineering, University of Nottingham-Ningbo China, Ningbo 315100, China; The Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute, Ningbo 315100, China
| | - Chengjun Wang
- College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan 430074, China.
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5
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Schneider SR, Lakey PSJ, Shiraiwa M, Abbatt JPD. Reactive Uptake of Ozone to Simulated Seawater: Evidence for Iodide Depletion. J Phys Chem A 2020; 124:9844-9853. [PMID: 33196200 DOI: 10.1021/acs.jpca.0c08917] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of ozone with iodide in the ocean is a major ozone dry deposition pathway, as well as an important source of reactive iodine to the marine troposphere. Few prior laboratory experiments have been conducted with environmentally relevant ozone mixing ratios and iodide concentrations, leading to uncertainties in the rate of the reaction under marine boundary layer conditions. As well, there remains disagreement in the literature assessment of the relative contributions of an interfacial reaction via ozone adsorbed to the ocean surface versus a bulk reaction with dissolved ozone. In this study, we measure the uptake coefficient of ozone over a buffered, pH 8 salt solution replicating the concentrations of iodide, bromide, and chloride in the ocean over an ozone mixing ratio of 60-500 ppb. Due to iodide depletion in the solution, the measured ozone uptake coefficient is dependent on the exposure time of the solution to ozone and its mixing ratio. A kinetic multilayer model confirms that iodide depletion is occurring not only within ozone's reactodiffusive depth, which is on the order of microns for environmental conditions, but also deeper into the solution as well. Best model-measurement agreement arises when some degree of nondiffusive mixing is occurring in the solution, transporting iodide from deeper in the solution to a thin, diffusively mixed upper layer. If such mixing occurs rapidly in the environment, iodide depletion is unlikely to reduce ozone dry deposition rates. Unrealistically high bulk-to-interface partitioning of iodide is required for the model to predict a substantial interfacial component to the reaction, indicating that the Langmuir-Hinshelwood mechanism is not dominant under environmental conditions.
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Affiliation(s)
- Stephanie R Schneider
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON Canada
| | - Pascale S J Lakey
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Manabu Shiraiwa
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON Canada
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6
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Tinel L, Adams TJ, Hollis LDJ, Bridger AJM, Chance RJ, Ward MW, Ball SM, Carpenter LJ. Influence of the Sea Surface Microlayer on Oceanic Iodine Emissions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13228-13237. [PMID: 32975119 PMCID: PMC7586339 DOI: 10.1021/acs.est.0c02736] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 05/26/2023]
Abstract
The influence of organic compounds on iodine (I2) emissions from the O3 + I- reaction at the sea surface was investigated in laboratory and modeling studies using artificial solutions, natural subsurface seawater (SSW), and, for the first time, samples of the surface microlayer (SML). Gas-phase I2 was measured directly above the surface of liquid samples using broadband cavity enhanced absorption spectroscopy. I2 emissions were consistently lower for artificial seawater (AS) than buffered potassium iodide (KI) solutions. Natural seawater samples showed the strongest reduction of I2 emissions compared to artificial solutions with equivalent [I-], and the reduction was more pronounced over SML than SSW. Emissions of volatile organic iodine (VOI) were highest from SML samples but remained a negligible fraction (<1%) of the total iodine flux. Therefore, reduced iodine emissions from natural seawater cannot be explained by chemical losses of I2 or hypoiodous acid (HOI), leading to VOI. An interfacial model explains this reduction by increased solubility of the I2 product in the organic-rich interfacial layer of seawater. Our results highlight the importance of using environmentally representative concentrations in studies of the O3 + I- reaction and demonstrate the influence the SML exerts on emissions of iodine and potentially other volatile species.
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Affiliation(s)
- Liselotte Tinel
- Department
of Chemistry, University of York, York YO10 5DD, U.K.
| | - Thomas J. Adams
- School
of Chemistry, University of Leicester, Leicester LE1 7RH, U.K.
- Ricardo
Energy & Environment, Harwell, Oxfordshire OX11 0QR, U.K.
| | | | | | - Rosie J. Chance
- Department
of Chemistry, University of York, York YO10 5DD, U.K.
| | - Martyn W. Ward
- Department
of Chemistry, University of York, York YO10 5DD, U.K.
| | - Stephen M. Ball
- School
of Chemistry, University of Leicester, Leicester LE1 7RH, U.K.
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7
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Moreno C, Baeza-Romero MT, Sanz M, Gálvez Ó, López Arza V, Ianni JC, Espíldora E. Iodide conversion to iodate in aqueous and solid aerosols exposed to ozone. Phys Chem Chem Phys 2020; 22:5625-5637. [PMID: 32101185 DOI: 10.1039/c9cp05601g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The aqueous-phase and surface reactions of ozone (O3) with iodide (I-) in/on seawater have been recently found to be a strong atmospheric source of iodine. In addition, ozone also reacts with I- in solid and aqueous sea-salt aerosol. However, the primary products of the heterogeneous reactions of ozone with I- have not been clarified. In this paper, solid and aqueous KI aerosols have been exposed to ozone in an aerosol flow tube system and I- and iodate (IO3-) concentrations have been measured by UV-Vis spectroscopy. The results of these experiments have been combined with a kinetic model to elucidate the primary products of the aqueous and surface reactions. The reaction of ozone with aqueous iodide has been inferred to originate different products depending on whether it occurs at the surface via O3 adsorption (product I2-) or in the aqueous phase via O3 solvation (product IO-). The surface reaction of ozone with solid KI in the presence of water vapor forms KIO3, and other species, which are likely to be gaseous. Although the reactions have been studied in aerosols, the results can be extrapolated to aqueous solutions as well.
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Affiliation(s)
- Carolina Moreno
- Universidad de Castilla-La Mancha, Escuela de Ingeniería Industrial y Aeroespacial, 45071, Toledo, Spain.
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8
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Pedersen HB, Elm J, Frederiksen CH, Jessen SPS, Teiwes R, Bilde M. The reaction of isotope-substituted hydrated iodide I(H182O) − with ozone: the reactive influence of the solvent water molecule. Phys Chem Chem Phys 2020; 22:19080-19088. [DOI: 10.1039/d0cp03219k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report an investigation of the reaction of isotope-substituted hydrated iodide I(H182O)− with ozone 16O3 to examine the involvement of the water molecules in the oxidation reactions that terminate with the formation of IO3−.
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Affiliation(s)
- Henrik B. Pedersen
- Department of Physics and Astronomy
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Jonas Elm
- Department of Chemistry
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | | | - Simon P. S. Jessen
- Department of Physics and Astronomy
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Ricky Teiwes
- Department of Physics and Astronomy
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Merete Bilde
- Department of Chemistry
- Aarhus University
- DK-8000 Aarhus C
- Denmark
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9
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Moreno C, Baeza-Romero MT. A kinetic model for ozone uptake by solutions and aqueous particles containing I - and Br -, including seawater and sea-salt aerosol. Phys Chem Chem Phys 2019; 21:19835-19856. [PMID: 31497813 DOI: 10.1039/c9cp03430g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The heterogeneous interactions of gaseous ozone (O3) with seawater and with sea-salt aerosols are known to generate volatile halogen species, which, in turn, lead to further destruction of O3. Here, a kinetic model for the interaction of ozone (O3) with Br- and I- solutions and aqueous particles has been proposed that satisfactorily explains previous literature studies about this process. Apart from the aqueous-phase reactions X- + O3 (X = I, Br), the interaction also involves the surface reactions X- + O3 that occur via O3 adsorption on the aqueous surface. In single salt solutions and aerosols, the partial order in ozone and the total order of the surface reactions are one, but the apparent total order is second order because the number of ozone sites where reaction can occur is equal to the surficial concentration of X- ([X-]surf). In the presence of Cl-, the surface reactions are enhanced by a factor equal to , where and . Therefore, we have inferred that Cl- acts as a catalyst in the surface reactions X- + O3. The model has been applied to estimate ozone uptake by the reaction with these halides in/on seawater and in/on sea-salt aerosol, where it has been concluded that the Cl--catalyzed surface reaction is important relative to total ozone uptake and should therefore be considered to model Y/YO (Y = I, Br, Cl) levels in the troposphere.
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Affiliation(s)
- Carolina Moreno
- Escuela de Ingeniería Industrial y Aeroespacial, Universidad de Castilla-La Mancha, 45071, Toledo, Spain.
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10
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Enami S, Hoffmann MR, Colussi AJ. Iodide Accelerates the Processing of Biogenic Monoterpene Emissions on Marine Aerosols. ACS OMEGA 2019; 4:7574-7580. [PMID: 31459850 PMCID: PMC6648763 DOI: 10.1021/acsomega.9b00024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 04/15/2019] [Indexed: 06/10/2023]
Abstract
Marine photosynthetic organisms emit organic gases, including the polyolefins isoprene (C5H8) and monoterpenes (MTPs, C10H16), into the boundary layer. Their atmospheric processing produces particles that influence cloud formation and growth and, as a result, the Earth's radiation balance. Here, we report that the heterogeneous ozonolysis of dissolved α-pinene by O3(g) on aqueous surfaces is dramatically accelerated by I-, an anion enriched in the ocean upper microlayer and sea spray aerosols (SSAs). In our experiments, liquid microjets of α-pinene solutions, with and without added I-, are dosed with O3(g) for τ < 10 μs and analyzed online by pneumatic ionization mass spectrometry. In the absence of I-, α-pinene does not detectably react with O3(g) under present conditions. In the presence of ≥ 0.01 mM I-, in contrast, new signals appear at m/z = 169 (C9H13O3 -), m/z = 183 (C10H15O3 -), m/z = 199 (C10H15O4 -), m/z = 311 (C10H16IO3 -), and m/z = 461 (C20H30IO4 -), plus m/z = 175 (IO3 -), and m/z = 381 (I3 -). Collisional fragmentation splits CO2 from C9H13O3 -, C10H15O3 - and C10H15O4 -, and I- plus IO- from C10H16IO3 - as expected from a trioxide IOOO•C10H16 - structure. We infer that the oxidative processing of α-pinene on aqueous surfaces is significantly accelerated by I- via the formation of IOOO- intermediates that are more reactive than O3. A mechanism in which IOOO- reacts with α-pinene (and likely with other unsaturated species) in competition with its isomerization to IO3 - accounts for present results and the fact that soluble iodine in SSA is mostly present as iodine-containing organic species rather than the thermodynamically more stable iodate. By this process, a significant fraction of biogenic MTPs and other unsaturated gases may be converted to water-soluble species rather than emitted to the atmosphere.
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Affiliation(s)
- Shinichi Enami
- National
Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
| | - Michael R. Hoffmann
- Linde
Center for Global Environmental Science, California Institute of Technology, Pasadena, California 91125, United States
| | - Agustín J. Colussi
- Linde
Center for Global Environmental Science, California Institute of Technology, Pasadena, California 91125, United States
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11
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Lee MT, Orlando F, Khabiri M, Roeselová M, Brown MA, Ammann M. The opposing effect of butanol and butyric acid on the abundance of bromide and iodide at the aqueous solution-air interface. Phys Chem Chem Phys 2019; 21:8418-8427. [PMID: 30945704 DOI: 10.1039/c8cp07448h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The efficient oxidation of iodide and bromide at the aqueous solution-air interface of the ocean or of sea spray aerosol particles had been suggested to be related to their surface propensity. The ubiquitous presence of organic material at the ocean surface calls for an assessment of the impact of often surface-active organic compounds on the interfacial density of halide ions. We used in situ X-ray photoelectron spectroscopy with a liquid micro-jet to obtain chemical composition information at aqueous solution-vapor interfaces from mixed aqueous solutions containing bromide or iodide and 1-butanol or butyric acid as organic surfactants. Core level spectra of Br 3d, Na 2s, C 1s and O 1s at ca. 160 eV kinetic energy and core level spectra of I 4d and O 1s at ca. 400 eV kinetic energy are compared for solutions with 1-butanol and butyric acid as a function of organic concentration. A simple model was developed to account for the attenuation of photoelectrons by the aliphatic carbon layer of the surfactants and for changing local density of bromide and iodide in response to the presence of the surfactants. We observed that 1-butanol increases the interfacial density of bromide by 25%, while butyric acid reduces it by 40%, both in comparison to the pure aqueous halide solution. Qualitatively similar behavior was observed for the case of iodide. Classical molecular dynamics simulations failed to reproduce the details of the response of the halide ions to the presence of the two organics. This is attributed to the lack of correct monovalent ion parameters at low concentration possibly leading to an overestimation of the halide ion concentration at the interface in absence of organics. The results clearly demonstrate that organic surfactants change the electrostatic interactions near the interface with headgroup specific effects. This has implications for halogen activation processes specifically when oxidants interact with halide ions at the aqueous solution-air interfaces of the ocean surface or sea spray aerosol particles.
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Affiliation(s)
- Ming-Tao Lee
- Laboratory of Environmental Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland.
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12
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Teiwes R, Elm J, Bilde M, Pedersen HB. The reaction of hydrated iodide I(H2O)− with ozone: a new route to IO2− products. Phys Chem Chem Phys 2019; 21:17546-17554. [DOI: 10.1039/c9cp01734h] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on an experimental characterization of the isolated reaction of hydrated iodide I(H2O)− with ozone O3 at room temperature performed using a radio-frequency ion trap combined with a quadrupole mass spectrometer.
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Affiliation(s)
- Ricky Teiwes
- Department of Physics and Astronomy
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Jonas Elm
- Department of Chemistry
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Merete Bilde
- Department of Chemistry
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Henrik B. Pedersen
- Department of Physics and Astronomy
- Aarhus University
- DK-8000 Aarhus C
- Denmark
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