Analysis of secondary organic aerosol formation and aging using positive matrix factorization of high-resolution aerosol mass spectra: application to the dodecane low-NOx system

• Published in: Atmospheric chemistry and physics 2012-01, Vol.12 (24), p.11795-11817
• Main Authors: Craven, J S, Yee, L D, Ng, N L, Canagaratna, M R, Loza, C L, Schilling, K A, Yatavelli, R L. N, Thornton, J A, Ziemann, P J, Flagan, R C, Seinfeld, J H
• Format: Article
• Language: English
• ISSN: 1680-7316; 1680-7324
• DOI: 10.5194/acp-12-11795-2012

Positive matrix factorization (PMF) of high-resolution laboratory chamber 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.