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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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Chung HY, Jung J, Yang K, Kim J, Kim K. Frozen Clay Minerals as a Potential Source of Bioavailable Iron and Magnetite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:19805-19816. [PMID: 37934905 DOI: 10.1021/acs.est.3c06144] [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: 11/09/2023]
Abstract
Iron (Fe) is an essential micronutrient that affects biological production. Iron-containing clay minerals are an important source of bioavailable iron. However, the dissolution of iron-containing clay minerals at temperatures below the freezing point has not been investigated. Here, we demonstrate the enhanced reductive dissolution of iron from a clay mineral in ice in the presence of iodide (I-) as the electron donor. The accelerated production of dissolved iron in the frozen state was irreversible, and the freeze concentration effect was considered the main driving force. Furthermore, the formation of magnetite (Fe3O4) after the freezing process was observed using transmission electron microscopy analysis. Our results suggest a new mechanism of accelerated abiotic reduction of Fe(III) in clay minerals, which may release bioavailable iron, Fe(II), and reactive iodine species into the natural environment. We also propose a novel process for magnetite formation in ice. The freezing process can serve as a source of bioavailable iron or act as a sink, leading to the formation of magnetite.
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Affiliation(s)
- Hyun Young Chung
- Korea Polar Research Institute (KOPRI), Incheon 21990, Korea
- Department of Polar Sciences, University of Science and Technology (UST), Incheon 21990, Korea
| | - Jaewoo Jung
- Ocean Georesources Research Department, Korea Institute of Ocean Science & Technology, Busan 49111, Korea
| | - Kiho Yang
- Department of Oceanography, Pusan National University, Busan 46241, Korea
| | - Jungwon Kim
- Department of Environmental Sciences and Biotechnology, Hallym University, Chuncheon, Gangwon-do 24252, Korea
| | - Kitae Kim
- Korea Polar Research Institute (KOPRI), Incheon 21990, Korea
- Department of Polar Sciences, University of Science and Technology (UST), Incheon 21990, Korea
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Ning A, Zhong J, Li L, Li H, Liu J, Liu L, Liang Y, Li J, Zhang X, Francisco JS, He H. Chemical Implications of Rapid Reactive Absorption of I 2O 4 at the Air-Water Interface. J Am Chem Soc 2023; 145:10817-10825. [PMID: 37133920 DOI: 10.1021/jacs.3c01862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Marine aerosol formation involving iodine-bearing species significantly affects the global climate and radiation balance. Although recent studies outline the critical role of iodine oxide in nucleation, much less is known about its contribution to aerosol growth. This paper presents molecular-level evidence that the air-water interfacial reaction of I2O4 mediated by potent atmospheric chemicals, such as sulfuric acid (H2SO4) and amines [e.g., dimethylamine (DMA) and trimethylamine (TMA)], can occur rapidly on a picosecond time scale by Born-Oppenheimer molecular dynamics simulations. The interfacial water bridges the reactants while facilitating the DMA-mediated proton transfer and stabilizing the ionic products of H2SO4-involved reactions. The identified heterogeneous mechanisms exhibit the dual contribution to aerosol growth: (i) the ionic products (e.g., IO3-, DMAH+, TMAH+, and HSO4-) formed by reactive adsorption possess less volatility than the reactants and (ii) these ions, such as alkylammonium salts (e.g., DMAH+), are also highly hydrophilic, further facilitating hygroscopic growth. This investigation enhances not only our understanding of heterogeneous iodine chemistry but also the impact of iodine oxide on aerosol growth. Also, these findings can bridge the gap between the abundance of I2O4 in the laboratory and its absence in field-collected aerosols and provide an explanation for the missing source of IO3-, HSO4-, and DMAH+ in marine aerosols.
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Affiliation(s)
- An Ning
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Jie Zhong
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, Shandong, China
| | - Liwen Li
- School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, Shandong, China
| | - Hao Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jiarong Liu
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Ling Liu
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yan Liang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Jing Li
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Xiuhui Zhang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Joseph S Francisco
- Department of Earth and Environmental Science and Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6316, United States
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Jones MR, Chance R, Dadic R, Hannula HR, May R, Ward M, Carpenter LJ. Environmental iodine speciation quantification in seawater and snow using ion exchange chromatography and UV spectrophotometric detection. Anal Chim Acta 2023; 1239:340700. [PMID: 36628710 DOI: 10.1016/j.aca.2022.340700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
The behaviour and distribution of iodine in the environment are of significant interest in a range of scientific disciplines, from health, as iodine is an essential element for humans and animals, to climate and air quality, to geochemistry. Aquatic environments are the reservoir for iodine, where it exists in low concentrations as iodide, iodate and dissolved organic iodine and in which it undergoes redox reactions. The current measurement techniques for iodine species are typically time-consuming, subject to relatively poor precision and require specialist instrumentation including those that require mercury as an electrode. We present a new method for measuring iodine species, that is tailored towards lower dissolved organic carbon waters, such as seawater, rainwater and snow, using ion exchange chromatography (IC) with direct ultra-violet spectrophotometric detection of iodide and without the need for sample pre-concentration. Simple chemical amendments to the sample allow for the quantification of both iodate and dissolved organic iodine in addition to iodide. The developed IC method, which takes 16 min, was applied to contrasting samples that encompass a wide range of aqueous environments, from Arctic sea-ice snow (low concentrations) to coastal seawater (complex sample matrix). Linear calibrations are demonstrated for all matrices, using gravimetrically prepared potassium iodide standards. The detection limit for the iodide ion is 0.12 nM based on the standard deviation of the blank, while sample reproducibility is typically <2% at >8 nM and ∼4% at <8 nM. Since there is no environmental certified reference material for iodine species, the measurements made on seawater samples using this IC method were compared to those obtained using established analytical techniques; iodide voltammetry and iodate spectrophotometry. We calculated recoveries of 102 ± 16% (n = 107) for iodide and 116 ± 9% (n = 103) for iodate, the latter difference may be due to an underestimation of iodate by the spectrophotometric method. We further compared a chemical oxidation and reduction of the sample to an ultra-violet digestion to establish the total dissolved iodine content, the average recovery following chemical amendments was 98 ± 4% (n = 92). The new method represents a simple, efficient, green, precise and sensitive method for measuring dissolved speciated iodine in complex matrices.
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Affiliation(s)
- Matthew R Jones
- Wolfson Atmospheric Chemistry Laboratory, University of York, York, YO10 5DD, UK.
| | - Rosie Chance
- Wolfson Atmospheric Chemistry Laboratory, University of York, York, YO10 5DD, UK
| | - Ruzica Dadic
- Victoria University of Wellington, Antarctic Research Centre, Wellington, 6140, New Zealand; WSL Institute for Snow and Avalanche Research SLF, 7260 Davos Dorf, Switzerland
| | - Henna-Reetta Hannula
- Finnish Meteorological Institute, Space and Earth Observation Centre, 00101, Helsinki, Finland
| | - Rebecca May
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK
| | - Martyn Ward
- Wolfson Atmospheric Chemistry Laboratory, University of York, York, YO10 5DD, UK
| | - Lucy J Carpenter
- Wolfson Atmospheric Chemistry Laboratory, University of York, York, YO10 5DD, UK
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