This is a past event.

​​​​​​Investigating Complex Mixtures using Ultrahigh Resolution Orbitrap Elite Mass Spectrometry: The Molecular Composition of Wildland Fire Aerosol

Wildland biomass burning, in the form of wildfires or prescribed burning, is an important source of organic aerosol to the atmosphere contributing to climate change, reductions in visibility, and adverse human health effects.  The molecular chemistry of atmospheric aerosol is important because it can be used to better understand its lifecycle and the physical properties of aerosol in the atmosphere.  In this work, we investigated the molecular properties of water-soluble organic carbon (WSOC) for five globally important fuels: Alaskan peat, Russian peat, Florida swamp peat, wildland cheat grass, and Ponderosa pine needles.  Aerosol from laboratory controlled combustion experiments was collected on filters and extracted in HPLC grade water.

Ultrahigh resolution electrospray ionization mass spectrometry and UV-Vis absorption measurements were performed after solid-phase extraction. Overall, most of the assigned molecular formulas demonstrated low O/C ratio (< 1) typical for fresh biomass combustion aerosols.  A greater molecular similarity was observed in peat burning aerosol samples compared to cheat grass and Ponderosa pine needle fuels.  This is most likely due to the difference in combustion; peat fuels only smolder, but cheat grass and pine needles have a flaming period before smoldering.

In this seminar, I will demonstrate the power of ultrahigh resolution mass spectrometry with an application to biomass combustion aerosol.