Kinetics and mechanism of OH-induced α-terpineol oxidation in the atmospheric aqueous phase

Kinetics and mechanism of α-terpineol oxidation by OH radicals were studied in the aqueous phase under acidic condition, and the optical properties of the reaction products were examined. Using the relative rate method, the rate constant of α-terpineol reaction with OH radicals was determined to be (1.3 ± 0.3) × 1010 M−1 s−1. The reaction products were analyzed by gas chromatography-mass spectrometry (GC-MS) and the reaction mechanism was proposed. The absorbance changes of the products were monitored by a UV–vis spectrophotometer, and α,β-unsaturated ketone compounds were observed. A certain distribution of α-terpineol in the aqueous phase has the potential to be conducive to the formation of aqueous secondary organic aerosols. At the same time, in order to investigate the persistence of α-terpineol in the atmosphere, its lifetime towards reaction with OH in atmospheric water was determined to be 6.2 h and 1.0 h in urban and remote area, respectively.