« Previous AbstractRepresentation of secondary organic aerosol laboratory chamber data for the interpretation of mechanisms of particle growth    Next Abstract[Volatile organic halogen compounds in food] »

Environ Sci Technol

Title:		Reactions of semivolatile organics and their effects on secondary organic aerosol formation
Author(s):		Kroll JH; Chan AW; Ng NL; Flagan RC; Seinfeld JH;
Address:		"Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, California 91125, USA"
Journal Title:		Environ Sci Technol
Year:		2007
Volume:		41
Issue:		10
Page Number:		3545 - 3550
DOI:		10.1021/es062059x
ISSN/ISBN:		0013-936X (Print) 0013-936X (Linking)
Abstract:		"Secondary organic aerosol (SOA) constitutes a significant fraction of total atmospheric particulate loading, but there is evidence that SOA yields based on laboratory studies may underestimate atmospheric SOA. Here we present chamber data on SOA growth from the photooxidation of aromatic hydrocarbons, finding that SOA yields are systematically lower when inorganic seed particles are not initially present. This indicates that concentrations of semivolatile oxidation products are influenced by processes beyond gas-particle partitioning, such as chemical reactions and/or loss to chamber walls. Predictions of a kinetic model in which semivolatile compounds may undergo reactions in both the gas and particle phases in addition to partitioning are qualitatively consistent with the observed seed effect, as well as with a number of other recently observed features of SOA formation chemistry. The behavior arises from a kinetic competition between uptake to the particle phase and reactive loss of the semivolatile product. It is shown that when hydrocarbons react in the absence of preexisting organic aerosol, such loss processes may lead to measured SOA yields lower than would occur under atmospheric conditions. These results underscore the need to conduct studies of SOA formation in the presence of atmospherically relevant aerosol loadings"
Keywords:		"Aerosols/*chemistry Kinetics Light Models, Chemical Organic Chemicals/*chemistry Oxidation-Reduction Time Factors Volatilization;"
Notes:		"MedlineKroll, Jesse H Chan, Arthur W H Ng, Nga L Flagan, Richard C Seinfeld, John H eng Research Support, U.S. Gov't, Non-P.H.S. 2007/06/06 Environ Sci Technol. 2007 May 15; 41(10):3545-50. doi: 10.1021/es062059x"