Kinetics and Reaction Products of Ozone and Surface-Bound Squalene

    Volume 5, Issue 7 (July 2008)

    ISSN: 1546-962X

    CODEN: JAIOAD

    Published Online: 24 June 2008

    Page Count: 12


    Wells, J. R.
    Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV

    Morrison, Glenn C.
    Department of Civil, Architectural and Environmental Engineering, Missouri University of Science & Technology, Rolla, MO

    Coleman, Beverly K.
    Department of Civil and Environmental Engineering, University of California, Berkeley, CA

    (Received 6 December 2007; accepted 20 May 2008)

    Abstract

    Because of the high occupant density in aircraft, the surface chemistry of ozone and squalene, an important component of skin oil, was evaluated. A reaction probability of (45±14)×10−5 was determined for the reaction of squalene (2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene) with ozone (50 parts per billion (ppb)) on a glass plate surface using the Field and Laboratory Emission Cell (FLEC) Automation and Control System (FACS). To more clearly define part of squalene’s indoor environment degradation mechanism, gas-phase and surface-bound products of the squalene+O3 reaction were also investigated. Emitted products were captured in solution, derivatized with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA), and analyzed by gas chromatography and ion trap mass spectroscopy. The identified squalene+O3 reaction products were: 6-methyl-5-hepten-2-one (6MHO, ((CH3)2CCH(CH2)2 C(O)CH3)), glyoxal (ethanedial, HC(O)C(O)H), 4-oxopentanal (4OPA, CH3C(O)CH2CH2 CH(O)), and 6,10-dimethylundeca-5,9-dien-2-one (geranyl acetone). The compound 5,9,13-trimethyltetradeca-4,8,12-trienal is proposed as the other major squalene+O3 reaction product. This compound was determined from mass spectrometry coupled with plausible squalene+O3 reaction mechanisms based on previously published volatile organic compound+O3 gas-phase reaction mechanisms.


    Paper ID: JAI101629

    DOI: 10.1520/JAI101629

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    Author
    Title Kinetics and Reaction Products of Ozone and Surface-Bound Squalene
    Symposium Airliner Cabin Environment: Recent Progress in Characterization, 2008-04-11
    Committee D22