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Notice of Public Lecture: Julie Bennett

Faculty of Graduate Studies

Graduate Programme in Chemistry
A Candidate for the Degree of
Doctor of Philosophy.  

Title of Thesis:
Flow Reactor Studies of Aromatic Hydrocarbon Photo-Oxidation Products Using
On-Line Gas/Particle Separation and MS-MS Analysis

November 26, 2010 @ 1:30 pm – 2:15 pm
317 Petrie Science and Engineering Bldg.
York University

Abstract: Particulate matter in the atmosphere is a major pollutant that contributes to climate change, reduced visibility and negative human health impacts.  Secondary particulate matter formed from the photo-oxidation of hydrocarbons significantly contributes to the particulate matter concentration in the atmosphere, particularly in the Northern Hemisphere.  However, at this time there is a lack of understanding of the chemical reactions that produce the secondary particulate matter. To further the knowledge in this area, a system was developed to investigate the composition of hydrocarbon photo-oxidation products in the gas and particle phase.  The system consists of a gas phase photochemical flow reactor for hydrocarbon oxidation, a Counter Flow Membrane Denuder (CFMD) for online gas/particle separation and an APCI MS-MS (TAGA 6000E) for composition analysis.

This system has been used to study the HO initiated oxidation of three aromatic hydrocarbons, toluene, m-xylene and 1,3,5-trimethylbenzene.  The products formed during the experiment were a complex mixture of organic species in both the gas and particle phase.  A wide variety of species were identified in these experiments including aromatic ring retaining, non-aromatic ring retaining, straight chained and five member ring (furan) products.  These products contained both single and multiple functional groups including alcohol, aldehyde, carboxylic acid, ketone, nitro, quinone, furanone and furandione.  Identification of these products provides the ground work for the establishment of a set of hydrocarbon markers for use in ambient studies.  Markers can be used for source identification of individual hydrocarbons and classes of hydrocarbons and ultimately for use in pollution control strategies.

Updated on October 7th, 2014.