Production of methyl vinyl ketone and methacrolein via the hydroperoxyl pathway of isoprene oxidation
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Published:2013-06-14
Issue:11
Volume:13
Page:5715-5730
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ISSN:1680-7324
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Container-title:Atmospheric Chemistry and Physics
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language:en
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Short-container-title:Atmos. Chem. Phys.
Author:
Liu Y. J.ORCID, Herdlinger-Blatt I., McKinney K. A.ORCID, Martin S. T.
Abstract
Abstract. The photo-oxidation chemistry of isoprene (ISOP; C5H8) was studied in a continuous-flow chamber under conditions such that the reactions of the isoprene-derived peroxyl radicals (RO2) were dominated by the hydroperoxyl (HO2) pathway. A proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) with switchable H3O+ and NO+ reagent ions was used for product analysis. The products methyl vinyl ketone (MVK; C4H6O) and methacrolein (MACR; C4H6O) were differentiated using NO+ reagent ions. The MVK and MACR yields via the HO2 pathway were (3.8 ± 1.3)% and (2.5 ± 0.9)%, respectively, at +25 °C and < 2% relative humidity. The respective yields were (41.4 ± 5.5)% and (29.6 ± 4.2)% via the NO pathway. Production of MVK and MACR via the HO2 pathway implies concomitant production of hydroxyl ((6.3 ± 2.1)%) and hydroperoxyl ((6.3 ± 2.1)%) radicals, meaning a HOx recycling of (12.6 ± 4.2)% given that HO2 was both a reactant and product. Other isoprene oxidation products, believed to be mostly organic hydroperoxides, also contributed to the ion intensity at the same mass-to-charge (m/z) ratios as the MVK and MACR product ions for HO2-dominant conditions. These products were selectively removed from the gas phase by placement of a cold trap (−40 °C) inline prior to the PTR-TOF-MS. When incorporated into regional and global chemical transport models, the yields of MVK and MACR and the concomitant HOx recycling reported in this study can improve the accuracy of the simulation of the HO2 reaction pathway of isoprene, which is believed to be the fate of approximately half of atmospherically produced isoprene-derived peroxy radicals on a global scale.
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference59 articles.
1. Ammann, C., Spirig, C., Neftel, A., Steinbacher, M., Komenda, M., and Schaub, A.: Application of PTR-MS for measurements of biogenic VOC in a deciduous forest, Int. J. Mass. Spectrom., 239, 87–101, https://doi.org/10.1016/j.ijms.2004.08.012, 2004. 2. Aschmann, S. M. and Atkinson, R.: Formation yields of methyl vinyl ketone and methacrolein from the gas-phase reaction of O3 with isoprene, Environ. Sci. Technol., 28, 1539–1542, https://doi.org/10.1021/es00057a025, 1994. 3. Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J., Troe, J., and IUPAC Subcommittee: Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic species, Atmos. Chem. Phys., 6, 3625–4055, https://doi.org/10.5194/acp-6-3625-2006, 2006. 4. Benkelberg, H. J., Boge, O., Seuwen, R., and Warneck, P.: Product distributions from the OH radical-induced oxidation of but-1-ene, methyl-substituted but-1-enes and isoprene in NOx-free air, Phys. Chem. Chem. Phys., 2, 4029–4039, https://doi.org/10.1039/b002053m, 2000. 5. Blake, R. S., Wyche, K. P., Ellis, A. M., and Monks, P. S.: Chemical ionization reaction time-of-flight mass spectrometry: Multi-reagent analysis for determination of trace gas composition, Int. J. Mass. Spectrom., 254, 85–93, https://doi.org/10.1016/j.ijms.2006.05.021, 2006.
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