(644d) The Impact of Elemental Composition On Volatility Profiles in Organic Aerosol Particles

Although the presence of organic aerosols in the atmosphere has been implicated in matters pertaining both to human health and to the global climate, the actual role played by these aerosols is not yet fully understood, due to the immense number of components that may be found in the atmosphere. The development of a method for separating components of an aerosol particle allows us to readily analyze the correlation between elemental composition and the volatility of the organic components. A flow-tube reactor is employed to generate particles at varying degrees of oxidation. This stream of particles is then passed through a thermal denuder (TD) at a set of temperatures such that we are able to determine via high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) the elemental composition of organic components that are transferred to the vapor phase over a focused temperature range. In this paper, a set of submicron (~160 nm) particles of squalane (a highly branched C₃₀ alkane) is subjected to oxidation and sent to the TD/AMS system. Results will include comparison with model predictions of the relative breakdown of molecules by degree of oxidation, as well as discussion of implications for future modeling applications in which a range of volatility sets is used to describe the time-evolution of both primary and secondary organic aerosols.