Aerosol Brown Carbon from Dark Reactions of Syringol in Aqueous Aerosol Mimics

作者：Xu, Jian; Cui, Tianqu; Fowler, Brandon; Fankhauser, Alison; Yang, Kai; Surratt, Jason D.; McNeill, V. Faye^*

来源：ACS Earth and Space Chemistry, 2018, 2(6): 608-617.

DOI：10.1021/acsearthspacechem.8b00010

• aerosols
• particulate matter
• brown carbon
• atmospheric chemistry
• biomass burning

We performed a laboratory investigation of the chemical processing of syringol, a representative model phenolic compound emitted from wood burning, in concentrated aqueous salt solutions mimicking tropospheric aerosol particles. For solutions containing chloride salts, we observed the formation of light-absorbing organic products ("brown carbon"), accompanied by a phase separation, within 10 h under dark conditions. Products were characterized at the molecular level using ultraperformance liquid chromatography interfaced to diode array detection and high resolutionquadrupole time-of-flight mass spectrometry equipped with electrospray ionization and matrix-assisted laser desorption/ionization interfaced to high-resolution time-of-flight mass spectrometry. The ultraviolet-visible spectra, together with high-resolution mass spectra results, suggest that syringol can be oxidized by dissolved oxygen, and the presence of Cl- promotes this reaction. Our results provide new insights into the evolution of aerosol optical properties during aging, specifically the formation of aerosol brown carbon in biomass-burning plumes.

• 出版日期2018-6
• 单位复旦大学