| Abstract
| - Smog chamber FTIR techniques were used to study the atmospheric oxidation of methyl propionate in740 Torr of air in the presence of NOx at 296 ± 2K. Relative rate techniques were used to measurek(OH + CH3CH2C(O)OCH3) = (9.29 ± 1.13) × 10-13, k(Cl + CH3CH2C(O)OCH3) = (1.51 ± 0.22) ×10-11, k(Cl + CH3CH2C(O)OC(O)H) = (2.89 ± 0.35) × 10-12, k(Cl + CH3CH2C(O)OH) = (4.72 ± 0.62) ×10-12, and k(Cl + CH3C(O)C(O)OCH3) = (4.99 ± 0.96) × 10-13 cm3 molecule-1 s-1. The products (andmolar yields) formed in the Cl-atom initiated oxidation of methyl propionate were as follows: propionicformic anhydride (CH3CH2C(O)OC(O)H), 0.099 ± 0.019; propionic acid (CH3CH2C(O)OH), 0.139 ± 0.027;carbon monoxide, 0.132 ± 0.026; methyl pyruvate (CH3C(O)C(O)OCH3), 0.289 ± 0.057; acetaldehyde,0.077 ± 0.015; methoxy formylperoxynitrate (CH3OC(O)O2NO2), 0.083 ± 0.016; methyl glyoxylate(H(O)CC(O)OCH3), 0.111 ± 0.022; organic nitrates, 0.07 ± 0.02; and formaldehyde. These products accountfor 79 ± 16% of the loss of methyl propionate. The atmospheric oxidation mechanism of methyl propionateis presented and discussed.
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