Analytical Chemistry Seminar
Analytical & Environmental Chemistry Division and Atmospheric Chemistry Program Seminar
Jointly sponsored by the Department of Chemistry and Biochemistry, CIRES, and the Environmental Program
Understanding the Molecular Signature of Atmospheric Organic Aerosols using Ion Mobility Mass Spectrometry
by Dr. Xuan Zhang Scientist I, NCAR
I will present some recent developments on the Ion Mobility Mass Spectrometer (IMS) that measures the collision cross section () and mass-to- charge ratio (m/z) of charged molecules. A two-dimensional space based on these two quantities is developed to facilitate the comprehensive investigation of complex organic mixtures in the atmosphere. Species of the same chemical class, despite variations in the molecular structures, tend to develop a unique distribution pattern by following a trend line on the space. The characteristics of trend lines for a variety of functionalities that are commonly present in the atmosphere can be predicted by the core model simulations, which provide a useful tool to identify the chemical class to which an unknown species belongs on the space. Furthermore, molecular characterization of labile species such as multi-functional organic nitrates and highly oxidized organic molecules in the condensed phase using the IMS technique is discussed.