| Title: | Hydroxydicarboxylic acids: markers for secondary organic aerosol from the photooxidation of alpha-pinene |
| Author(s): | Claeys M; Szmigielski R; Kourtchev I; van der Veken P; Vermeylen R; Maenhaut W; Jaoui M; Kleindienst TE; Lewandowski M; Offenberg JH; Edney EO; |
| Address: | "Department of Pharmaceutical Sciences, University of Antwerp (Campus Drie Eiken), Universiteitsplein 1, BE-2610 Antwerp, Belgium. magda.claeys@ua.ac.be" |
| ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
| Abstract: | "Detailed organic analysis of fine (PM2.5) rural aerosol collected during summer at K-puszta, Hungary from a mixed deciduous/coniferous forest site shows the presence of polar oxygenated compounds that are also formed in laboratory irradiated alpha-pinene/NOx/air mixtures. In the present work, two major photooxidation products of alpha-pinene were characterized as the hydroxydicarboxylic acids, 3-hydroxyglutaric acid, and 2-hydroxy-4-isopropyladipic acid, based on chemical, chromatographic, and mass spectral data. Different types of volatile derivatives, including trimethylsilyl ester/ether, methyl ester trimethylsilyl ether, and ethyl ester trimethylsilyl ether derivatives were measured by gas chromatography/mass spectrometry (GC/MS), and their electron ionization (El) spectra were interpreted in detail. The proposed structures of the hydroxydicarboxylic acids were confirmed or supported with reference compounds. 2-Hydroxy-4-isopropyladipic acid formally corresponds to a further reaction product of pinic acid involving addition of a molecule of water and opening of the dimethylcyclobutane ring; this proposal is supported by a laboratory irradiation experiment with alpha-pinene/NOJ0 air. In addition, we report the presence of a structurally related minor alpha-pinene photooxidation product, which was tentatively identified as the C7 homolog of 3-hydroxyglutaric acid, 3-hydroxy-4,4-dimethylglutaric acid. The detection of 2-hydroxy-4-isopropyladipic acid in ambient aerosol provides an explanation for the relatively low atmospheric concentrations of pinic acid found during daytime in forest environments" |
| Keywords: | "Aerosols/*analysis Bicyclic Monoterpenes Dicarboxylic Acids/*analysis Monoterpenes/*chemistry Oxidation-Reduction Photochemistry Reference Standards Spectrometry, Mass, Electrospray Ionization;" |
| Notes: | "MedlineClaeys, Magda Szmigielski, Rafal Kourtchev, Ivan van der Veken, Pieter Vermeylen, Reinhilde Maenhaut, Willy Jaoui, Mohammed Kleindienst, Tadeusz E Lewandowski, Michael Offenberg, John H Edney, Edward O eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2007/04/03 Environ Sci Technol. 2007 Mar 1; 41(5):1628-34. doi: 10.1021/es0620181" |
