Mechanism of the OH-initiated oxidation of glycolaldehyde over the temperature range 233-296 K.

The mechanism of the gas-phase OH-initiated oxidation of glycolaldehyde (HOCH(2)CHO) was studied in the 233-296 K temperature range using a turbulent flow reactor coupled with a chemical ionization mass spectrometer. In the presence of O2, formaldehyde, CO2, formic acid, and glyoxal were observed at room temperature with the yields of 80, 34, 18, and 14%, respectively. Decrease of temperature to 233 K led to significant changes in the yields of the stable products: those of formaldehyde and glyoxal decreased to 50 and 4%, respectively, whereas that of formic acid increased to 52%.

Mechanism of the OH-initiated oxidation of hydroxyacetone over the temperature range 236-298 K.

The mechanism of the gas-phase reaction of OH radicals with hydroxyacetone (CH3C(O)CH2OH) was studied at 200 Torr over the temperature range 236-298 K in a turbulent flow reactor coupled to a chemical ionization mass-spectrometer. The product yields and kinetics were measured in the presence of O2 to simulate the atmospheric conditions. The major stable product at all temperatures is methylglyoxal.