| Abstract
| - With use of a droplet train apparatus, the uptake by 1-octanol of gas-phase α-pinene, γ-terpinene, p-cymene,and 2-methyl-2-hexanol was measured as a function of relative humidity and temperature (263−293 K).1-Octanol was selected as a surrogate for hydrophobic oxygenated organic compounds found in troposphericaerosols. The mass accommodation coefficients (α) of γ-terpinene, p-cymene, and 2-methyl-2-hexanol obtainedfrom these measurements exhibit negative temperature dependences. The upper and lower values of α at 265and 290 K, respectively, are as follows: for γ-terpinene 0.12 and 0.076; for p-cymene 0.20 and 0.097; andfor 2-methyl-2-hexanol 0.25 and 0.11. The uptake of α-pinene is solubility limited, yielding values for theproduct HDl1/2 for α-pinene in 1-octanol (H = Henry's law constant, Dl = liquid-phase diffusion coefficient).With use of estimated values of Dl the Henry's law constant is obtained as ln H (M/atm) = −(6.59 ± 1.16)+ (3.80 ± 0.31) × 103/T. The presence of water vapor does not affect the uptake of the above organicgas-phase species. Uptakes of the gas-phase species benzene, H2O, SO2, and H2S were also studied and werefound to below the detection limit of the droplet apparatus. This implies that the uptake coefficient for thesespecies is less than 10-3 for trace gas/liquid droplet interaction times up to 1.5 × 10-2 s.
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