Evaluating the Changing Mass Spectra Signature and Secondary Impact of Emissions Generated by Charbroiling Beef Hamburger Patties Using Data from Environmental Chamber and Oxidation Flow Reactor Experiments

Commercial cooking emissions are a growing concern in regions like the South Coase Air Basin, and while extensive research has been conducted to evaluate the primary emissions from this source, limited research has been conducted regarding the formation of secondary organic aerosol (SOA) from this source. The research for this thesis used an environmental chamber and an oxidation flow reactor (OFR) to evaluate the emissions generated by beef hamburger charbroiling, already established as the cooking method and meat type that predominantly contributes to commercial cooking emissions. For unfiltered environmental chamber experiments, representing both the primary organic aerosol (POA) and SOA created by this source, the %SOA production evolved from 13 ± 5.6% to 24 ± 6.7% over four hours while the %SOA for the filtered environmental chamber experiments, representing only SOA produced from gaseous emissions of this source, remained relatively stable at 90 ± 9.8% on average. Using the results from the OFR with data from the environmental chamber experiments, linear combination of variables was used to find 57% SOA production for the unfiltered emissions. Additionally, the mass spectra for these experiments were evaluated and a significant change in character was observed from start to finish of the environmental chamber experiments and between individual experiment types, showing an increased oxidation and a shift towards smaller organic ions with increasing atmospheric exposure. Angle theta was used to quantify this change. From start to finish, a change of 19.3 ± 2.6° was observed for the unfiltered environmental chamber experiments and a change of 51.8 ± 3.5° was observed between the start and the finish of the filtered chamber experiments. This supports the finding that SOA from meat charbroiling is far more ready to participate in atmospheric chemistry than POA emissions. Comparing the OFR spectrum to the initial unfiltered and final filtered spectra respectively yielded an angle theta of 46.2 ± 0.9° and 19.3 ± 4.4°. Altogether, the early findings from this research show that the secondary impact of commercial cooking emissions has significantly been underestimated in previous research and that this emission source has a far greater SOA forming potential than suspected