Simultaneous Uptake of DMS and Ozone on Water

The simultaneous uptake of gas-phase DMS−O 3 mixtures by water as a function of temperature (274−300 K) was studied in a bubble train flow reactor. The uptake data yielded the second-order rate constant for the aqueous-phase reaction DMS + O 3 → DMSO + O 2 . The reaction products were established with NMR analysis. The reaction rate constant k 2 was measured at four temperatures: 274, 283, 293, and 300 K, yielding (5.1 ± 2.0) × 10 8 M -1 s -1, (5.9 ± 2.0) × 10 8 M -1 s -1, (8.6 ± 3.6) × 10 8 M -1 s -1, and (11 ± 4.5) × 10 8 M -1 s -1 respectively. It is noteworthy that the magnitude of the aqueous reaction rate constant exceeds the corresponding gas-phase rate by a factor of about 10 6 . The atmospheric importance of the aqueous-phase DMS/O 3 reaction is discussed.