Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Quantitative Evidence for Organic Peroxy Radical Photochemistry

Published

Author(s)

William S. McGivern, Joseph Klems

Abstract

Quantitative evidence for the importance of alkyl peroxy photochemistry in the formation of secondary organic aerosol at 254 nm. Dodecanoic acid has been oxidized extensively in a flow cell by photolytically generated hydroxyl radicals to create particles. The resulting particles were collected and analyzed for composition, which shows much less multiply substituted parent molecules and much more decomposition product than expected from typical low-NOx oxidation mechanisms. Modeling studies were done to demonstrate this for two separate reaction times, and theoretical work from the combustion literature was used to estimate the branching of the photoexcited products. In addition, the alkyl peroxy radical absorption is sufficiently strong at 310 nm that the photochemical lifetime under pristine tropospheric conditions is similar to predicted lifetimes from peroxy-peroxy recombination reactions.
Citation
Journal of Physical Chemistry A
Volume
119

Keywords

alkyl peroxy radicals, secondary organic aerosol, photochemistry
Created December 12, 2014, Updated November 10, 2018