Abstract. In order to enlarge our understanding of biomass burning
plume chemistry, the OH-radical-initiated oxidation of 3-penten-2-one (3P2),
identified in biomass burning emissions, and 2-hydroxypropanal (2HPr) was investigated at 298 ± 3 K and 990 ± 15 mbar in two atmospheric
simulation chambers using long-path FTIR spectroscopy. The rate coefficient
of 3P2 + OH was determined to be (6.2 ± 1.0) × 10−11 cm3 molec.−1 s−1 and the molar first-generation yields for
acetaldehyde, methyl glyoxal, 2HPr, and the sum of peroxyacetyl nitrate (PAN) and CO2, used to
determine the CH3C(O) radical yield, were 0.39 ± 0.07,
0.32 ± 0.08, 0.68 ± 0.27, and 0.56 ± 0.14, respectively,
under conditions where the 3P2-derived peroxy radicals react solely with NO.
The 2HPr + OH reaction was investigated using 3P2 + OH as a source of
the α-hydroxyaldehyde adjusting the experimental conditions to shift
the reaction system towards secondary oxidation processes. The rate
coefficient was estimated to be (2.2 ± 0.6) × 10−11 cm3 molec.−1 s−1. Employing a simple chemical mechanism to
analyse the temporal behaviour of the experiments, the further oxidation of
2HPr was shown to form methyl glyoxal, acetaldehyde, and CO2 with
estimated yields of 0.27 ± 0.08, 0.73 ± 0.08, and 0.73 ± 0.08, respectively.