Accession Number DE2012-1055680
Title OH-Initiated Heterogeneous Aging of Highly Oxidized Organic Aerosol.
Publication Date Dec 2011
Media Count 23p
Personal Author C. E. Kolb D. R. Worsnop J. D. Smith J. H. Kroll K. E. Daumit K. R. Wilson S. H. Kessler S. R. Leone T. Nah
Abstract The oxidative evolution (aging) of organic species in the atmosphere is thought to have a major influence on the composition and properties of organic particulate matter, but remains poorly understood, particularly for the most oxidized fraction of the aerosol. Here we measure the kinetics and products of the heterogeneous oxidation of highly oxidized organic aerosol, with an aim of better constraining such atmospheric aging processes. Submicron particles composed of model oxidized organics-1,2,3, 4-butanetetracarboxylic acid (C(sub 8)H(sub 10)O(sub 8)),citric acid (C(sub 6)H(sub 8)O(sub 7)), tartaric acid (C(sub 4)H(sub 6)O(sub 6)), and Suwannee River fulvic acid-were oxidized by gas-phase OH in a flow reactor, and the masses and elemental composition of the particles were monitored as a function of OH exposure. In contrast to our previous studies of less-oxidized model systems (squalane, erythritol, and levoglucosan), particle mass did not decrease significantly with heterogeneous oxidation. Carbon content of the aerosol always decreased somewhat, but this mass loss was approximately balanced by an increase in oxygen content. The estimated reactive uptakecoefficients of the reactions range from 0.37 to 0.51 and indicate that such transformations occur at rates corresponding to 1-2 weeks in the atmosphere, suggesting their importance in the atmospheric lifecycle of organic particulate matter.
Keywords Aerosols
Aging
Atmospheric composition
Chemical properties
Chemical reactions
Exposure
Kinetics
Organic compounds
Oxidation
Particulates


 
Source Agency Technical Information Center Oak Ridge Tennessee
NTIS Subject Category 68A - Air Pollution & Control
55 - Atmospheric Sciences
99A - Analytical Chemistry
99F - Physical & Theoretical Chemistry
Corporate Author Lawrence Berkeley National Lab., CA.
Document Type Technical report
Title Note N/A
NTIS Issue Number 1309
Contract Number DE-AC02-05CH11231

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