Molecular characterization of biomass burning aerosols using high-resolution mass spectrometry.
Chemical characterization of atmospheric aerosols presents a serious analytical challenge because of the complexity of particulate matter analyte composed of a large number of compounds with a wide range of molecular structures, physico-chemical properties, and reactivity. In this study the chemical composition of the organic constituents of biomass burning aerosol (BBA) samples is characterized by high-resolution electrospray ionization mass spectrometry (ESI/MS). Accurate mass measurement combined with Kendrick analysis allows assignment of the elemental composition for hundreds of compounds in the range of m/z values of 50-1000. ESI/MS spectra of different BBA samples contain a variety of distinct, sample specific, characteristic peaks that can be used as unique markers for different types of biofuels. Our results indicate that a significant number of high-MW organic compounds in BBA samples are highly oxidized polar species that can be efficiently detected using ESI/MS but are difficult to observe using conventional gas-chromatography/mass spectrometry analysis of aerosol samples. More than 70% of the identified species have not been reported in the literature. Detected organic compounds show a clear increase in the degree of saturation as the molecular weight of the analyte molecules increases. The increase is particularly pronounced for the samples containing a large number of the CH(2)-based homologous series.
Smith
Jeffrey S
JS
Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, MSIN K8-88, Richland, Washington 99352, USA.
Laskin
Alexander
A
Laskin
Julia
J
D000336:Aerosols; D018533:Biomass; D000432:Methanol / Q000737:chemistry; D009930:Organic Chemicals / Q000032:analysis / Q000737:chemistry*; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization
D000336:Aerosols; D009930:Organic Chemicals; D000432:Methanol