Phenolic carbonyls undergo rapid aqueous photodegradation to form low-volatility, light-absorbing products

摘要: Abstract We investigated the aqueous photochemistry of six phenolic carbonyls - vanillin, acetovanillone, guaiacyl acetone, syringaldehyde, acetosyringone, and coniferyl aldehyde – that are emitted from wood combustion. The absorb significant amounts solar radiation decay rapidly via direct photodegradation, with lifetimes (τ) 13–140 min under Davis, CA winter solstice sunlight at midday (solar zenith angle = 62°). one exception is where carbonyl group not directly connected to aromatic ring: This species absorbs very little undergoes photodegradation slowly (τ > 103 min). also found triplet excited states (3C*) oxidize syringol (a methoxyphenol without a group), on timescales 1–5 h for solutions containing 5 μM carbonyl. carbonyls, oxidation by 3C*, both efficiently produce low volatility products, SOA mass yields ranging 80 140%. Contrary most aliphatic typical fog conditions we find primary sink in phase. In areas combustion, appear be small but sources SOA: over course few hours, nearly all will converted enhancing POA combustion approximately 3–5%.