Aqueous oxidation of green leaf volatiles by hydroxyl radical as a source of SOA: Kinetics and SOA yields

• Published in: Atmospheric environment (1994) Vol. 95; pp. 105 - 112
• Main Authors: Richards-Henderson, Nicole K., Hansel, Amie K., Valsaraj, Kalliat T., Anastasio, Cort
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2014; Elsevier
• Subjects: Applied sciences; Atmospheric pollution; Biogenic volatile organic compounds; Chemical kinetics; Exact sciences and technology; Multiphase chemistry; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Secondary organic aerosol; Biogenic volatile organic compounds; Secondary organic aerosol; Multiphase chemistry; Chemical kinetics; Natural origin pollution; Water drop; Pollutant formation; Alcohol; Volatile organic compound; Aldehyde; Precursor; Chemical reaction kinetics; Biogenic factor; Atmospheric chemistry; Reaction mechanism; Air pollution; Organic compounds; Fog; Hydrometeor
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2014.06.026

Green leaf volatiles (GLVs) are a class of oxygenated hydrocarbons released from vegetation, especially during mechanical stress or damage. The potential for GLVs to form secondary organic aerosol (SOA) via aqueous-phase reactions is not known. Fog events over vegetation will lead to the uptake of GLVs into water droplets, followed by aqueous-phase reactions with photooxidants such as the hydroxyl radical (OH). In order to determine if the aqueous oxidation of GLVs by OH can be a significant source of secondary organic aerosol, we studied the partitioning and reaction of five GLVs: cis-3-hexen-1-ol, cis-3-hexenyl acetate, methyl salicylate, methyl jasmonate, and 2-methyl-3-butene-2-ol. For each GLV we measured the kinetics of aqueous oxidation by OH, and the corresponding SOA mass yield. The second-order rate constants for GLVs with OH were all near diffusion controlled, (5.4–8.6) × 109 M−1 s−1 at 298 K, and showed a small temperature dependence, with an average activation energy of 9.3 kJ mol−1 Aqueous-phase SOA mass yields ranged from 10 to 88%, although some of the smaller values were not statistically different from zero. Methyl jasmonate was the most effective aqueous-phase SOA precursor due to its larger Henry's law constant and high SOA mass yield (68 ± 8%). While we calculate that the aqueous-phase SOA formation from the five GLVs is a minor source of aqueous-phase SOA, the availability of other GLVs, other oxidants, and interfacial reactions suggest that GLVs overall might be a significant source of SOA via aqueous reactions. [Display omitted] •We assessed the potential contribution of aqueous GLV reactions as a source of SOA.•Second-order rate constants for GLVs with OH ranged from (5.4–8.6) × 109 M−1 s−1.•Aqueous-phase SOA mass yields ranged from 10 to 88%.•Calculations show that SOA formation from these GLVs is a minor contributor to SOA.