Heterogeneous Glyoxal Oxidation: A Potential Source of Secondary Organic Aerosol

Connelly, B. M., D. O. De Haan, and M. Tolbert (2012), Heterogeneous Glyoxal Oxidation: A Potential Source of Secondary Organic Aerosol, J. Phys. Chem. A, 116, 6180-6187, doi:10.1021/jp211502e.
Abstract: 

Laboratory studies are described that suggest reactive uptake of glyoxal on particulate containing HNO3 could contribute to the formation of secondary organic aerosol (SOA) in the upper troposphere (UT). Using a Knudsen cell flow reactor, glyoxal is observed to react on supercooled H2O/HNO3 surfaces to form condensed-phase glyoxylic acid. This product was verified by derivatization and GC−MS analysis. The reactive uptake coefficient, γ, of glyoxal varies only slightly with the pressure of nitric acid, from γ = 0.5 to 3.0 × 10−3 for nitric acid pressures between 10−8 and 10−6 Torr. The data do not show any dependence on temperature (181−201 K) or pressure of glyoxal (10−7 to 10−5 Torr). Using the determined reactive uptake kinetics in a simple model shows that glyoxal uptake to supercooled H2O/HNO3 may account for 4−53% of the total organic mass fraction of aerosol in the UT.

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Research Program: 
Radiation Science Program (RSP)