Atmospheric Chemistry Program Seminar
Experimental Investigation of the Particle-Phase Products and Reaction Mechanism of Δ-3-Carene with NO3 Radicals
"Oxidation products of monoterpenes have been shown to contribute to secondary organic aerosol (SOA) formation in the atmosphere. However, the nighttime oxidative processes, which are dominated by nitrate radical (NO3) addition to alkenes, are not well understood. In order to fill this gap, I am working to quantify the yields of particle-phase products of the nitrate radical-initiated oxidation of Δ-3-carene, a monoterpene that is primarily emitted by coniferous plants. Using functional groups analysis methods, liquid chromatography with UV-Vis detection, and electrospray and electron ionization mass spectrometry to characterize SOA formed in environmental chamber reactions, I have identified a series of acetal dimers. The mechanism derived from these measured particle-phase products will help to inform chemical transport models on the contribution of nighttime oxidation of monoterpenes to SOA. In addition, these acetal dimers are analogous to those that have been identified and quantified in the β-pinene + NO3 radical system, and appear to form from reactions of a variety of monoterpenes."