Key Role of NO3 Radicals in the Production of Isoprene Nitrates and Nitrooxyorganosulfates in Beijing

Jacqueline F. Hamilton, Daniel Bryant, Peter Edwards, Bin Quyang, Thomas Bannan, Archit Mehra, Alfred Mayhew, James R. Hopkins, Rachel E. Dunmore, Freya Squires, James Lee, Mike J. Newland, Stephen Worrall, Asan Bacak, Hugh Coe, Carl Percival, Lisa Whalley, Dwayne E. Heard, Eloise Slater, Roderic JonesTianqu Cui, Jason Surratt, Claire Reeves, Graham Mills, Sue Grimmond, Yele Sun, Weidi Xu, Zongbo Shi, Andrew R. Rickard

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The formation of isoprene nitrates (IsN) can lead to significant secondary organic aerosol (SOA) production and they can act as reservoirs of atmospheric nitrogen oxides. In this work, we estimate the rate of production of IsN from the reactions of isoprene with OH and NO3 radicals during the summertime in Beijing. While OH dominates the loss of isoprene during the day, NO3 plays an increasingly important role in the production of IsN from the early afternoon onwards. Unusually low NO concentrations during the afternoon resulted in NO3 mixing ratios of ca. 2 pptv at approximately 15:00, which we estimate to account for around a third of the total IsN production in the gas phase. Heterogeneous uptake of IsN produces nitrooxyorganosulfates (NOS). Two mono-nitrated NOS were correlated with particulate sulfate concentrations and appear to be formed from sequential NO3 and OH oxidation. Di- and tri-nitrated isoprene-related NOS, formed from multiple NO3 oxidation steps, peaked during the night. This work highlights that NO3 chemistry can play a key role in driving biogenic–anthropogenic interactive chemistry in Beijing with respect to the formation of IsN during both the day and night.
Original languageEnglish
Pages (from-to)842–853
Number of pages12
JournalEnvironmental Science & Technology
Volume55
Issue number2
Early online date7 Jan 2021
DOIs
Publication statusPublished - 19 Jan 2021

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