I am a Ph.D. candidate in the Department of Chemistry at the California Institute of Technology. Before coming to Caltech, I studied Environmental Chemistry at the University of California, Riverside.
As both an analytical and atmospheric chemist, my research couples gas chromatography and mass spectrometry in order to study important gas-phase reactions that occur in the atmosphere. I am especially interested in the reactions that occur between transported urban pollution and local biogenic emissions.
About my Research
Though it may appear simple at a glance, our atmosphere is actually a complicated soup of compounds. The majority of these compounds fall under a class called oxygenated volatile organic compounds (OVOCs), which are made up of highly reactive species that play key roles in the formation of air pollutants such as tropospheric ozone and secondary organic aerosols. Unfortunately, despite being such an important group of compounds, analytical challenges have hampered our ability to make ambient measurements of OVOCs. More specifically, many sampling techniques available today have difficulty differentiating between structural isomers of OVOCs. Since slight differences in structure can result in dramatic differences in the properties of a compound (and, as a result, determine how a specific OVOC will impact our air quality), my research has mainly revolved around developing different mass spectrometry methods so that we can more accurately characterize the chemical composition of our atmosphere.
My largest project by far has been combining the isomer separation capabilities of gas chromatography (GC) with the fast and sensitive detection of time-of-flight chemical ionization mass spectrometer (ToF-CIMS), in order to achieve isomer-resolved quantification of OVOCs in real time. Through the development and field deployment of this, aptly named, GC-CIMS, I have obtained the first isomer-resolved, ambient measurements of important organic nitrates made through the reaction of anthropogenic NOx and biogenic isoprene. Furthermore, I am using this novel dataset to explore whether an isomer-specific sink of these nitrates is responsible for discrepancies between field observations and model estimates of NOx, ozone and nitric acid.
In addition, I have recently began working with a triple quadrupole mass spectrometer to develop a method that allows it to differentiate between isomers of various aromatics compounds commonly produced by anthropogenic (e.g. industrial processes) and natural (e.g. wildfire) means. Since different formation pathways lead to a different distribution of isomers, this isomer-resolved quantification will allow us to tease out where an aromatic compound came from. Though it's too early to tell, preliminary results from the triple's deployment during FIREX-AQ look promising.