Title: | Secondary organic aerosol formation from high-NO(x) photo-oxidation of low volatility precursors: n-alkanes |
Author(s): | Presto AA; Miracolo MA; Donahue NM; Robinson AL; |
Address: | "Center for Atmospheric Particle Studies, Carnegie Mellon University, USA" |
ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
Abstract: | "Smog chamber experiments were conducted to investigate secondary organic aerosol (SOA) formation from photo-oxidation of low-volatility precursors; n-alkanes were chosen as a model system. The experiments feature atmospherically relevant organic aerosol concentrations (C(OA)). Under high-NO(x) conditions SOA yields increased with increasing carbon number (lower volatility) for n-decane, n-dodecane, n-pentadecane, and n-heptadecane, reaching a yield of 0.51 for heptadecane at a C(OA) of 15.4 microg m(-3). As with other photo-oxidation systems, aerosol yield increased with UV intensity. Due to the log-linear relationship between n-alkane carbon number and vapor pressure as well as a relatively consistent product distribution it was possible to develop an empirical parametrization for SOA yields for n-alkanes between C(12) and C(17). This parametrization was implemented using the volatility basis set framework and is designed for use in chemical transport models. For C(OA) < 2 microg m(-3), the SOA mass spectrum, as measured with an aerosol mass spectrometer, had a large contribution from m/z 44, indicative of highly oxygenated products. At higher C(OA), the mass spectrum was dominated by m/z 30, indicative of organic nitrates. The data support the conclusion that lower volatility organic vapors are important SOA precursors" |
Keywords: | "Aerosols/*chemical synthesis Air Pollutants/analysis/*chemical synthesis Alkanes/*chemistry Atmosphere/chemistry Environmental Monitoring Nitrogen Oxides/*chemistry Oxidants, Photochemical/chemistry Oxidation-Reduction Smog/analysis Volatile Organic Compo;" |
Notes: | "MedlinePresto, Albert A Miracolo, Marissa A Donahue, Neil M Robinson, Allen L eng Research Support, U.S. Gov't, Non-P.H.S. 2010/02/20 Environ Sci Technol. 2010 Mar 15; 44(6):2029-34. doi: 10.1021/es903712r" |