10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Measuring Functional Group Composition in Complex Environmental Samples: Infrared Photodissociation of Ions from Secondary Organic Aerosol
Emma Walhout, Jonathan Martens, Giel Berden, Jos Oomens, Jesse Kroll, RACHEL O'BRIEN, College of William and Mary
Abstract Number: 397 Working Group: Instrumentation
Abstract Secondary organic aerosols (SOA) are a large fraction of the organic particulate matter in the atmosphere with impacts on climate, air quality, and human health. The effect of aerosols on the climate is one of the largest uncertainties in estimates of radiative forcing. Much of this uncertainty is driven by the complexity of the organic fraction, with thousands of different molecules in an aerosol population. Mass spectrometry can be used to analyze the molecular composition of organic aerosols, however, information on the chemical structure and functional groups is typically lost with this type of analysis. By combining information on the functional groups and the molecular formulas in an aerosol sample, we can work towards identification of individual molecules in the mixtures. Infrared multi-photon dissociation (IRMPD) uses IR radiation to fragment ions in a mass spectrometer. With a tunable free electron laser as the light source, an action spectrum for ions can be generated in the fingerprint IR region (~600-1900 cm-1). These spectra, in combination with the fragment ions (MS/MS type fragments), provide details on the chemical structures of the ions. In this work we present the first application of IRMPD analysis, using the FELIX tunable free electron laser, to characterize compounds in SOA produced via ozonolysis of a-pinene.