galactosan and dehydroabietic-acid

This is a brief review key to the literature on the determination of organic tracers from biomass burning which are detectable even after long-range global transport in total extracts of atmospheric particles. The major tracers are thermal degradation products from the biopolymer cellulose, namely the didehydromonosaccharide derivatives levoglucosan, galactosan and mannosan and the resin acid derivative dehydroabietic acid, with minor beta-sitosterol. Dehydroabietic acid is emitted primarily from burning of conifer fuel and these tracers are found in most aerosol samples from the North American continent. Particulate matter from the atmosphere over oceanic areas contains organic tracers from both natural and biomass burning emissions. The major biomarker compounds characterized are natural products from continental vegetation consisting primarily of epicuticular wax components and trace components from biomass burning emissions. The presence of these tracers in atmospheric particulate matter over the ocean confirms the long-range transport of smoke from biomass burning off the continents.

Topics: Abietanes; Air Pollutants; Atmosphere; Biomass; Cellulose; Diterpenes; Environmental Monitoring; Fires; Galactose; Gas Chromatography-Mass Spectrometry; Glucose; Mannose; Organic Chemicals; Smoke; Sterols

The particulate emissions from biomass burning are a growing concern due to the recent evidence of their ubiquitous and important contribution to the ambient aerosol load. A possible strategy to apportion the biomass burning share of particulate matter is the use of organic molecular tracers. Anhydrosugars (levoglucosan, mannosan and galactosan), together with two organic acids (dehydroabietic and pimaric acids), were previously reported as organic markers for particulate wood burning emissions. These five compounds were studied in four European cities (Helsinki, Copenhagen, Birmingham and Oporto), at both a Roadside and an Urban Background station, during a summer and a winter campaign in the fine (PM(2.5)) and the coarse (PM(10-2.5)) size-fractions of the ambient aerosol. Levoglucosan concentrations were highest in the city of Oporto. In winter, levoglucosan was more present in the fine fraction but in summer, concentrations were similar in both size fractions. Levoglucosan concentrations in the fine size fraction were higher in winter, but no seasonal differences were observed for the coarse size fraction. The lack of difference between the Roadside and Urban Background levoglucosan concentrations points towards a regional nature of this type of pollution. Wood burning was estimated to contribute to about 3.1% of the winter PM(10) mass in Oporto, and to 3.7% in Copenhagen. Mannosan followed the trends exhibited by levoglucosan. The ratio between the levoglucosan and mannosan concentrations allowed determination of a preference for softwood over hardwood in all four cities. Galactosan, pimaric acid and dehydroabietic acid were found to be minor compounds.

Topics: Abietanes; Air Pollutants; Air Pollution; Atmosphere; Cities; Diterpenes; Environmental Monitoring; Galactose; Mannose; Particulate Matter; Seasons; Wood