Source Profiles of Organic Compounds Emitted upon Combustion of Green Vegetation from Temperate Climate Forests

Biomass burning is an important primary source of particles containing biomarker compounds, which are introduced into smoke primarily by direct volatilization/steam stripping and by thermal alteration based on combustion conditions. This study presents comprehensive organic compound source profiles for smoke from controlled burning of green vegetation native to the predominant temperate and semiarid forests of the western United States. Smoke particles were extracted with dichloromethane/methanol (2:1, v/v), and the extracts were analyzed as their TMS derivatives by gas chromatography−mass spectrometry. Carbohydrates were by far the major compound class emitted in smoke particles, encompassing 57−77% of the total extractable organic compounds detected here. Lignin derivatives (5−17%) and diterpenoids (up to 16%) from bleed resins were the next most abundant compound groups observed. The major individual compounds encompassed methyl-inositols (up to 41%, e.g., pinitol) for conifer smokes, deoxy-inositols (up to 32%, e.g., quercitol) for samples containing oak vegetation, and the thermally altered product of cellulose combustion levoglucosan (14−21%). The remaining compound classes, i.e., n-alkanoic acids, n-alkanols, n-alkanes, triterpenoids, steroids, and polycyclic aromatic hydrocarbons, were present at lower abundances (mostly