Volatility of complex laboratory-generated organic aerosol mixtures
ANDREY KHLYSTOV, Ming-Yeng Lin
Abstract Number: 282
Working Group: Aerosol Chemistry
Last modified: April 3, 2011
Ambient aerosol, a significant portion of which is composed of a complex mixture of semi-volatile organic compounds, has substantial impact on human welfare via adverse health effects and global climate change. Prediction of ambient semi-volatile organic aerosol remains highly problematic and air quality models often do not agree with observations. Ideally, a model should take into account volatility, activity coefficients, and molecular weights of individual compounds. However, due to the lack of experimental data and computational challenges, the ambient aerosol system is usually simplified to a limited set of surrogate compounds, such as the Volatility Basis Set (VBS). Models are being currently developed that extend this approach by adding the second dimension on the oxygenation or polarity of compounds. However, there is practically no experimental verification that any of these approaches can accurately represent volatility behavior of complex organic mixtures. In this study we investigated volatility behavior of complex laboratory-generated organic aerosol mixtures. The mixtures were composed of different combinations of alkanes, mono- and di-carboxylic acids. The results of the experiments and the performance of the VBS representations in describing volatility of these systems will be presented.