Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6337266 | Atmospheric Environment | 2016 | 9 Pages |
Abstract
Methoxyphenols, lignin pyrolysis products, are major biomass combustion components and are considered potential tracers for wood smoke emissions. Their atmospheric reactivity, however, has not been well characterized. Guaiacol, creosol, and syringol are three typical methoxyphenols generated in relatively high concentrations in fresh wood smoke. In this study, the gas-phase reactions of NO3 radicals with these methoxyphenols were investigated using a laboratory-built vacuum ultraviolet photoionization gas time-of-flight mass spectrometer (VUV-GTOFMS) and off-line GC-MS. By combining experimental and theoretical methods, 4-nitroguaiacol, 6-nitroguaiacol, and 4,6-dinitroguaiacol were determined as the primary degradation products for guaiacol; similarly, 6-nitrocreosol and 3-nitrosyringol were identified for creosol and syringol, respectively. Using the relative rate method, rate constants at 298 K and 1 atm for the gas-phase reactions of guaiacol, creosol, and syringol with NO3 radicals were measured to be 3.2 Ã 10â12, 2.4 Ã 10â13, and 4.0 Ã 10â13 cm3 moleculeâ1 sâ1, respectively. At a typical tropospheric concentration of NO3 radicals (5 Ã 108 molecule cmâ3), atmospheric lifetimes for guaiacol, creosol, and syringol toward NO3 radicals were 0.2, 2.3, and 1.4 h, respectively. These results indicate that the reaction with NO3 radicals can be a major sink for methoxyphenols at night.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Atmospheric Science
Authors
Bo Yang, Haixu Zhang, Youfeng Wang, Peng Zhang, Jinian Shu, Wanqi Sun, Pengkun Ma,