title: Determination of organic acids in aerosol particles from a coniferous forest by liquid chromatography-mass spectrometry.
abstract: LC-MS methods with use of ion-trap and time-of-flight mass spectrometers were developed for the determination of organic acids in aerosol samples collected by a high-volume sampler in a Finnish coniferous forest. Comparison was made of the composition of samples collected during atmospheric formation of new aerosol particles and on days when this formation did not occur. A dynamic sonication-assisted solvent extraction system was developed for fast and quantitative extraction of the filter samples. Several organic acids, including pinonic acid, pinic acid, and homologous series of n-alkanoic acids, n-alkenoic acids, and aliphatic dicarboxylic acids, were identified. In samples collected between 08:00 and 16:00 hours the concentration of pinonic acid ranged from 0.5 ng m(-3) to 3.7 ng m(-3) and that of pinic acid from 0.2 ng m(-3) to 1.5 ng m(-3). For most of the compounds identified, the trends in concentration could be explained by the differences in temperature during collection. However, concentrations of short-chain n-alkanoic acids were clearly higher on the days when new aerosol particle formation occurred.
authors.affiliation: laboratory of Analytical Chemistry, Department of Chemistry, P.O. Box 55, FIN-00014 University of Helsinki, Finland.
authors.forename: Piia
authors.initials: P
authors.lastname: Anttila
authors.forename: Tuulia
authors.initials: T
authors.lastname: Hyötyläinen
authors.forename: Anu
authors.initials: A
authors.lastname: Heikkilä
authors.forename: Matti
authors.initials: M
authors.lastname: Jussila
authors.forename: Johan
authors.initials: J
authors.lastname: Finell
authors.forename: Markku
authors.initials: M
authors.lastname: Kulmala
authors.forename: Marja-Liisa
authors.initials: ML
authors.lastname: Riekkola
mesh_terms: D000143:Acids / Q000032:analysis* / Q000737:chemistry*; D000336:Aerosols / Q000032:analysis* / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry; D009930:Organic Chemicals / Q000737:chemistry*; D014197:Trees / Q000737:chemistry*
chemical_list: D000143:Acids; D000336:Aerosols; D009930:Organic Chemicals