1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
2Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA
3Aerodyne Research, Inc., Billerica, MA, USA
4Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
5Air Pollution Research Center, Department of Environmental Sciences, and Environmental Toxicology Graduate Program, University of California, Riverside, CA, USA
6School of Chemical and Biomolecular Engineering and School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
**now at: Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO, USA
Abstract. Positive matrix factorization (PMF) of high-resolution laboratory aerosol mass spectra is applied for the first time, the results of which are consistent with molecular level MOVI-HRToF-CIMS aerosol-phase and CIMS gas-phase measurements. Secondary organic aerosol was generated by photooxidation of dodecane under low-NOx conditions in the Caltech environmental chamber. The PMF results exhibit three factors representing a combination of gas-particle partitioning, chemical conversion in the aerosol, and wall deposition. The slope of the measured high-resolution aerosol mass spectrometer (HR-ToF-AMS) composition data on a Van Krevelen diagram is consistent with that of other low-NOx alkane systems in the same O:C range. Elemental analysis of the PMF factor mass spectral profiles elucidates the combinations of functionality that contribute to the slope on the Van Krevelen diagram.