Our research activities are focused on understanding the identities, occurrence and transformation of aerosol organic compounds. Changing aerosol composition affects aerosol physical properties and hence affects aerosol-climate interactions. First, we exploit advanced mass spectrometry methods such FT-ICR MS to identify and characterize aerosol organic compounds by their empirical formulas. This identification step is furthered by MS/MS analysis to investigate the structural aspects of individual organic compounds. Since atmospheric organic matter is very complex, we also work with advanced liquid chromatography techniques for increased analyte resolution and identification. Our samples, are collected from a variety of ambient environments and are generated in house to explore secondary organic aerosol components. We are especially interested in aqueous reaction pathways and thus are developing a reaction chamber for investigation of aerosol-droplet chemistry.
Advanced Mass Spectrometry Methods
Electrospray - mass spectrometry (ESI-MS) is a sensitive and robust analytical technique for identification of unknown organic compouds. Due to the complex nature of atmospheric aerosol organic compounds we employ a variety of ESI-MS techniques. Our lab is equipped with an ESI-Ion Trap Mass Spectrometer which has the unique ability to perform multiple stages of mass spectrometry (MSn) in one space. MSn is extremely useful for obtaining structural information of unknown analytes. These experiments can then be paired with ultrahigh-resolution FT-ICR mass measurements for molecular formula determinations. The combination of structural information and empirical formula assignments are good steps toward understanding the chemical nature of aerosol organic components.
Photos by Mariusz Nowak of the Michigan Tech Photo Services.
May 2012: "High Molecular Weight SOA Formation during Limonene Ozonolysis: Insights from Ultrahigh-Resolution FT-ICR Mass Spectrometry Characterization" is in press with Atmospheric Chemistry and Physics.
April 2012: Megan Dalbec receives a Summer Undergraduate Research Fellowship. Congratulations, Megan.
April 2012: "Identification of Water-Soluble Organic Carbon in Nonurban Aerosols using Ultrahigh-Resolution FT-ICR Mass Spectrometry: Organic Anions" is in press as part of a special Research Front Issue of Environmental Chemistry.