Low-Molecular-Weight Carboxylic Acids in the Southeastern U.S. : Formation, Partitioning, and Implications for Organic Aerosol Aging

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

1 Scopus Citations
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Author(s)

  • Yunle Chen
  • Hongyu Guo
  • David J. Tanner
  • Amy P. Sullivan
  • Masayuki Takeuchi
  • Gao Ziqi
  • Petros Vasilakos
  • Armistead G. Russell
  • Karsten Baumann
  • L. Gregory Huey
  • Rodney J. Weber
  • Nga Lee Ng

Detail(s)

Original languageEnglish
Pages (from-to)6688-6699
Number of pages12
Journal / PublicationEnvironmental Science and Technology
Volume55
Issue number10
Online published27 Apr 2021
Publication statusPublished - 18 May 2021
Externally publishedYes

Abstract

While carboxylic acids are important components in both particle and gas phases in the atmosphere, their sources and partitioning are not fully understood. In this study, we present real-time measurements of both particle- and gas-phase concentrations for five of the most common and abundant low-molecular-weight carboxylic acids (LMWCA) in a rural region in the southeastern U.S. in Fall 2016. Through comparison with secondary organic aerosol (SOA) tracers, we find that isoprene was the most important local precursor for all five LMWCA but via different pathways. We propose that monocarboxylic acids (formic and acetic acids) were mainly formed through gas-phase photochemical reactions, while dicarboxylic acids (oxalic, malonic, and succinic acids) were predominantly from aqueous processing. Unexpectedly high concentrations of particle-phase formic and acetic acids (in the form of formate and acetate, respectively) were observed and likely the components of long-range transport organic aerosol (OA), decoupled from their gas-phase counterparts. In addition, an extraordinarily strong correlation (R2 = 0.90) was observed between a particulate LMWCA and aged SOA, which we tentatively attribute to boundary layer dynamics.

Citation Format(s)

Low-Molecular-Weight Carboxylic Acids in the Southeastern U.S. Formation, Partitioning, and Implications for Organic Aerosol Aging. / Chen, Yunle; Guo, Hongyu; Nah, Theodora; Tanner, David J.; Sullivan, Amy P.; Takeuchi, Masayuki; Ziqi, Gao; Vasilakos, Petros; Russell, Armistead G.; Baumann, Karsten; Huey, L. Gregory; Weber, Rodney J.; Ng, Nga Lee.

In: Environmental Science and Technology, Vol. 55, No. 10, 18.05.2021, p. 6688-6699.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review