title: Heterogeneous chemistry of glyoxal on acidic solutions. An oligomerization pathway for secondary organic aerosol formation.
abstract: The heterogeneous chemistry of glyoxal on sulfuric acid surfaces has been investigated at various acid concentrations and temperatures, utilizing a low-pressure fast flow laminar reactor coupled to an ion drift-chemical ionization mass spectrometer (ID-CIMS). The uptake coefficient (γ) of glyoxal ranges from (1.2 ± 0.06) × 10(-2) to (2.5 ± 0.01) × 10(-3) for 60-93 wt % H2SO4 at 253-273 K. The effective Henry's Law constant (H*) ranges from (98.9 ± 4.9) × 10(5) to (1.6 ± 0.1) × 10(5) M atm(-1) for 60-93 wt % at 263-273 K. Both the uptake coefficient and Henry's Law constant increase with decreasing acid concentration and temperature. Our results reveal a reaction mechanism of hydration followed by oligomerization for glyoxal on acidic media, indicating an efficient aqueous reaction of glyoxal on hygroscopic particles leading to secondary organic aerosol formation.
authors.forename: Mario E
authors.initials: ME
authors.lastname: Gomez
authors.forename: Yun
authors.initials: Y
authors.lastname: Lin
authors.forename: Song
authors.initials: S
authors.lastname: Guo
authors.forename: Renyi
authors.initials: R
authors.lastname: Zhang
mesh_terms: D000336:Aerosols / Q000737:chemistry*; D006037:Glyoxal / Q000737:chemistry*; D013058:Mass Spectrometry; D011312:Pressure; D012996:Solutions; D013464:Sulfuric Acids / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry; D017155:Wettability
chemical_list: D000336:Aerosols; D012996:Solutions; D013464:Sulfuric Acids; D014867:Water; D006037:Glyoxal; C033158:sulfuric acid