Formation of substances with humic-like fluorescence properties, upon photoinduced oligomerization of typical phenolic compounds emitted by biomass burning

• Published in: Atmospheric environment (1994) Vol. 206; pp. 197 - 207
• Main Authors: Vione, Davide, Albinet, Alexandre, Barsotti, Francesco, Mekic, Majda, Jiang, Bin, Minero, Claudio, Brigante, Marcello, Gligorovski, Sasho
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-06-2019; Elsevier
• Subjects: Aerosol; Biomass burning; Chemical Sciences; HuLiS; Methoxyphenols; Photolysis; Photolysis; Methoxyphenols; HuLiS; Aerosol; Biomass burning; Aerosol Biomass burning HuLiS Photolysis Methoxyphenols
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2019.03.005

The irradiation under simulated sunlight of some phenolic compounds typically emitted in ambient air by biomass burning, namely vanillin and acetosyringone, yielded intermediates with humic-like fluorescence properties that can be assimilated to humic-like substances (HULIS). Evidence was obtained by ultra-high-resolution mass spectrometry of the occurrence of oligomerization processes up to the formation of trimeric species. In contrast, the irradiation of other biomass-burning compounds such as vanillic acid, m-cresol and guaiacol did not yield either HULIS-type fluorescence or oligomers. We suggest that the photolysis of biomass-burning compounds is a potential HULIS source in the atmosphere, if the relevant substrates undergo photoinduced oligomerization reactions.
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•Humic-like fluorescence is produced by irradiation of biomass-burning phenols.•Vanillin and acetosyringone are involved in the process.•Evidence of oligomerization, up to formation of trimeric species.•Norrish-type and phenoxyl reactions are reasonable oligomerization pathways.•This is a potential route to atmospheric humic-like substances (HULIS).