AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
The Acid-Dependent Hydrolysis of Organic Nitrates in the Aerosol Phase
JOEL RINDELAUB, Kevin McAvey, Paul Shepson, Purdue University
Abstract Number: 135 Working Group: Aerosol Chemistry
Abstract The atmospheric production of organic nitrates under high NOx conditions can influence regional ozone concentrations and the oxidative capacity of the atmosphere by controlling the fate of nitric oxides through possible sink/reservoir processes. However, the degree of this effect is uncertain as photolysis, oxidation, and further reactions within the particle phase may dictate the fate of these compounds. Recent research has indicated that hydrolysis may be a significant reaction pathway for organic nitrates in the particle phase and could influence the equilibrium partitioning of the system. To further investigate the fate of organic nitrates in the aerosol phase, we conducted high NOx oxidation experiments of alpha–pinene in a photochemical reaction chamber focusing on the partitioning and particle phase stability of organic nitrates as a function of seed aerosol acidity, relative humidity, and aerosol composition. The total organic nitrate yield from these experiments was highly dependent on both seed aerosol acidity and chamber relative humidity, even at low RH. Here we will discuss our analysis of the aerosol phase composition, to attempt to decipher the nature of the aerosol phase chemistry that impacts organic nitrate partitioning. These experiments provide useful insight into the nature of some of the aerosol phase processes that might impact the fate of atmospheric organic nitrates, as well as the composition of SOA.