Chemical characterization of biogenic secondary organic aerosol generated from plant emissions under baseline and stressed conditions: inter- and intra-species variability for six coniferous species

Journal Article · Wed Apr 01 00:00:00 EDT 2015 · Atmospheric Chemistry and Physics (Online)

DOI: https://doi.org/10.5194/acp-15-3629-2015 · OSTI ID:1228144

Faiola, C. L. ; Wen, M.; VanReken, T. M.

The largest global source of secondary organic aerosol (SOA) in the atmosphere is derived from the oxidation of biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. Alterations to the biogenic volatile organic compound (BVOC) profile could impact the characteristics of the SOA formed from those emissions. This study investigated the impacts of one global change stressor, increased herbivory, on the composition of SOA derived from real plant emissions. Herbivory was simulated via application of methyl jasmonate (MeJA), a proxy compound. Experiments were repeated under pre- and post-treatment conditions for six different coniferous plant types. Volatile organic compounds (VOCs) emitted from the plants were oxidized to form SOA via dark ozone-initiated chemistry. The SOA chemical composition was measured using a Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-AMS). The aerosol mass spectra of pre-treatment biogenic SOA from all plant types tended to be similar with correlations usually greater than or equal to 0.90. The presence of a stressor produced characteristic differences in the SOA mass spectra. Specifically, the following m/z were identified as a possible biogenic stress AMS marker with the corresponding HR ion(s) shown in parentheses: m/z 31 (CH₃O⁺), m/z 58 (C₂H₂O₂⁺, C₃H₆O⁺), m/z 29 (C₂H₅⁺), m/z 57 (C₃H₅O⁺), m/z 59 (C₂H₃O₂⁺, C₃H₇O⁺), m/z 71 (C₃H₃O₂⁺, C₄H₇O⁺), and m/z 83 (C₅H₇O⁺). The first aerosol mass spectrum of SOA generated from the oxidation of the plant stress hormone, MeJA, is also presented. Elemental analysis results demonstrated an O : C range of baseline biogenic SOA between 0.3 and 0.47. The O : C of standard MeJA SOA was 0.52. Results presented here could be used to help identify a biogenic plant stress marker in ambient data sets collected in forest environments.

• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
• Grant/Contract Number: SC0003899
• OSTI ID: 1228144
• Journal Information: Atmospheric Chemistry and Physics (Online), Journal Name: Atmospheric Chemistry and Physics (Online) Journal Issue: 7 Vol. 15; ISSN 1680-7324
• Publisher: Copernicus Publications, EGUCopyright Statement
• Country of Publication: Germany
• Language: English