Hydroxydicarboxylic Acids: Markers for Secondary Organic Aerosol from the Photooxidation of α-Pinene
- 23 January 2007
- journal article
- Published by American Chemical Society (ACS) in Environmental Science & Technology
- Vol. 41 (5), 1628-1634
- https://doi.org/10.1021/es0620181
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.This publication has 30 references indexed in Scilit:
- Biogenic contributions to the chemical composition of airborne particles in a coniferous forest in GermanyAtmospheric Environment, 2006
- Chemical Composition of Secondary Organic Aerosol Formed from the Photooxidation of IsopreneThe Journal of Physical Chemistry A, 2006
- Formation of secondary organic particle phase compounds from isoprene gas-phase oxidation products: An aerosol chamber and field studyAtmospheric Environment, 2006
- Observation of 2-methyltetrols and related photo-oxidation products of isoprene in boreal forest aerosols from Hyytiälä, FinlandAtmospheric Chemistry and Physics, 2005
- Formation of 2-methyl tetrols and 2-methylglyceric acid in secondary organic aerosol from laboratory irradiated isoprene/NOX/SO2/air mixtures and their detection in ambient PM2.5 samples collected in the eastern United StatesAtmospheric Environment, 2005
- Alpha-pinene oxidation by OH: simulations of laboratory experimentsAtmospheric Chemistry and Physics, 2004
- Polar organic oxygenates in PM2.5 at a southeastern site in the United StatesAtmospheric Environment, 2003
- Secondary organic aerosol formation from the oxidation of aromatic hydrocarbons in the presence of dry submicron ammonium sulfate aerosolAtmospheric Environment, 1999
- Newly characterized products and composition of secondary aerosols from the reaction of α-pinene with ozoneAtmospheric Environment, 1999
- Formation and gas/particle partitioning of monoterpenes photo‐oxidation products over forestsGeophysical Research Letters, 1999