title: HPLC-MS determination of the oxidation products of the reaction between alpha- and beta-pinene and OH radicals.
abstract: Biogenic non-methane hydrocarbons such as isoprene, alpha-pinene, and beta-pinene, are emitted by forests in very large quantities. To evaluate the role of alpha- and beta-pinene and their contribution to the global production of trace gases and especially aerosol precursors, a study of the oxidation mechanism of alpha- and beta-pinene with hydroxyl radicals must be conducted. The degradation products of both monoterpenes with hydroxyl radicals were identified and quantified in a fast-flow reactor. The products were collected on a liquid-nitrogen trap coated with a 2,4-DNPH solution to which two internal standards (benzaldehyde-2,4-DNPH and tolualdehyde-2,4-DNPH) had been added. The collection method was based on the in situ conversion of aldehyde and/or ketone compounds to their 2,4-dinitrophenylhydrazone derivatives. The derivatives were analyzed by HPLC-MS using APCI(-). TIC chromatograms and mass spectral data for the various oxidation products are presented. For alpha-pinene, pinonaldehyde is the most important degradation product, with smaller amounts of acetone, formaldehyde, campholenealdehyde, and acetaldehyde. For beta-pinene, nopinone and formaldehyde are the most abundant products, of almost equal importance, whereas acetone and acetaldehyde are minor compounds.
authors.affiliation: Department of Chemistry, KULeuven, Celestijnenlaan 200F, 3001 Leuven, Belgium. viviane.vandenbergh@chem.kuleuven.ac.be
authors.forename: V
authors.initials: V
authors.lastname: Van den Bergh
authors.forename: H
authors.initials: H
authors.lastname: Coeckelberghs
authors.forename: I
authors.initials: I
authors.lastname: Vanhees
authors.forename: R
authors.initials: R
authors.lastname: De Boer
authors.forename: F
authors.initials: F
authors.lastname: Compernolle
authors.forename: C
authors.initials: C
authors.lastname: Vinckier