Strong anthropogenic control of secondary organic aerosol formation from isoprene in Beijing

Research output: Contribution to journalArticle

Authors

  • Daniel J. Bryant
  • William J. Dixon
  • James R. Hopkins
  • Rachel E. Dunmore
  • Kelly L. Pereira
  • Marvin Shaw
  • Freya A. Squires
  • Thomas J. Bannan
  • Archit Mehra
  • Stephen D. Worrall
  • Asan Bacak
  • Hugh Coe
  • Carl J. Percival
  • Lisa K. Whalley
  • Dwayne E. Heard
  • Eloise J. Slater
  • Bin Ouyang
  • Tianqu Cui
  • Jason D. Surratt
  • Yele Sun
  • Weiqi Xu
  • Alastair C. Lewis
  • James D. Lee
  • Andrew R. Rickard
  • Jacqueline F. Hamilton

Colleges, School and Institutes

External organisations

  • Department of Environmental Sciences/Center of Excellence in Environmental Studies, King Abdulaziz University
  • Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York
  • Wolfson Atmospheric Chemistry Laboratory, Department of Chemistry, University of York
  • School of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
  • School of Chemistry, University of Leeds, Leeds, UK
  • Lancaster Environment Centre, Lancaster University, Lancaster, UK
  • Department of Environmental Sciences and Engineering, Gillings School of Global Health, University of North Carolina, Chapel Hill, USA
  • Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, PR China
  • University of Manchester
  • Institute of Atmospheric Physics Chinese Academy of Sciences
  • University of York

Abstract

Isoprene-derived secondary organic aerosol (iSOA) is a significant contributor to organic carbon (OC) in some forested regions, such as tropical rainforests and the Southeastern US. However, its contribution to organic aerosol in urban areas that have high levels of anthropogenic pollutants is poorly understood. In this study, we examined the formation of anthropogenically influenced iSOA during summer in Beijing, China. Local isoprene emissions and high levels of anthropogenic pollutants, in particular NOx and particulate SO42-, led to the formation of iSOA under both high- and low-NO oxidation conditions, with significant heterogeneous transformations of isoprene-derived oxidation products to particulate organosulfates (OSs) and nitrooxyorganosulfates (NOSs). Ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry was combined with a rapid automated data processing technique to quantify 31 proposed iSOA tracers in offline PM2:5 filter extracts. The co-elution of the inorganic ions in the extracts caused matrix effects that impacted two authentic standards differently. The average concentration of iSOA OSs and NOSs was 82.5 ngm􀀀3, which was around 3 times higher than the observed concentrations of their oxygenated precursors (2-methyltetrols and 2-methylglyceric acid). OS formation was dependant on both photochemistry and the sulfate available for reactive uptake, as shown by a strong correlation with the product of ozone (O3) and particulate sulfate (SO42-). A greater proportion of high-NO OS products were observed in Beijing compared with previous studies in less polluted environments. The iSOA-derived OSs and NOSs represented 0.62% of the oxidized organic aerosol measured by aerosol mass spectrometry on average, but this increased to _ 3% on certain days. These results indicate for the first time that iSOA formation in urban Beijing is strongly controlled by anthropogenic emissions and results in extensive conversion to OS products from heterogenous reactions.

Details

Original languageEnglish
Pages (from-to)7531–7552
Number of pages22
JournalAtmospheric Chemistry and Physics
Volume20
Publication statusPublished - 30 Jun 2020