ATMOSPHERIC DEGRADATION OF GLYCIDALDEHYDE - PHOTOLYSIS AND REACTION WITH OH RADICALS

Epoxide aldehydes have recently been detected among the oxidation prod ucts of aromatic hydrocarbons. Many epoxides are toxic and very little is known about their atmospheric fate. The products and kinetics of t he atmospheric oxidation, OH radical reaction, and photolysis of glyci daldehyde have been investigated in a large volume reactor at 298 K us ing in situ long-path FT-IR spectroscopy for the analysis. A rate coef ficient of k = (1.69 +/- 0.04) x 10(-11) cm(3) molecule(-1) s(-1) has been determined for the reaction of glycidaldehyde with the OH radical using the relative kinetic technique. The UV absorption spectrum of g lycidaldehyde was measured in the range 220-380 nm from which upper li mits of its photolysis frequencies in the troposphere have been deduce d, e.g., J (hv) similar to 1.0 x 10(-4) s(-1) (for July 1, noon, and 5 0 degrees N). The OH radical initiated photooxidation of glycidaldehyd e yields CO, CO2, formic acid, formic acid anhydride, formaldehyde, an d hydroperoxymethyl formate as major products. A reaction mechanism is postulated to account for the product formation.