Quantitative assessment of organosulfates in size-segregated rural fine aerosol

Abstract

Abstract. Organosulfates have recently come into the focus of organic aerosol research as potentially important components of water-soluble secondary organic aerosol (SOA) which now dominate tropospheric fine aerosol. Their presence has been confirmed by the identification of sulfate esters of abundant biogenic carbonyl compounds in both smog chamber and continental aerosol. However, none of the studies have been able to determine the mass contribution of organosulfates to SOA. In this paper, as possibly the very first attempt to quantify organosulfates in ambient aerosol, we inferred the mass concentrations of organosulfates by concurrently determining mass concentrations of total sulfur, sulfate and methanesulfonate in rural fine aerosol using two highly sensitive analytical techniques. Although uncertainties were relatively large, we found that mass concentrations of organosulfates in water-soluble fine aerosol ranged from 0.02 μgS m−3 to 0.09 μgS m−3 yielding a mass contribution of 6–12% to bulk sulfur concentrations (or 6–14% to sulfate concentrations). The inferred size distribution of organosulfates suggested that they possibly form in heterogeneous reactions from semi-volatile carbonyl compounds with subsequent or concurrent condensation of gaseous sulfuric acid producing a refractory organic film on particle surfaces.

Organosulfate Formation in Biogenic Secondary Organic Aerosol

“…Despite the uncertainties associated with this estimate, it is clear that organosulfates may be responsible for a sizable fraction of ambient OM. In addition to our estimates, Lukács et al 64 recently showed that organosulfates in watersoluble fine aerosol, also collected from the K-puszta field site during the 2006 summer campaign, contribute 6-12% to the total sulfur concentration. Due to the likely importance of these estimates, it is essential that the detailed chemical characterization of organosulfates be conducted as this will lead to improved understanding of their formation pathways in ambient organic aerosol.…”

“…Furthermore, it has been suggested that organosulfate formation occurs on the acidic surface (and not in the bulk) of a fine ambient aerosol particle as a result of condensation of semivolatile organic vapors and subsequent reaction with sulfuric acid and gives rise to a refractory organic film. 64,95 It would be worthwhile to confirm in further studies with suitable analytical techniques (e.g., transmission electron microscopy) the occurrence of organosulfates on the surface of ambient fine aerosols.…”

Secondary organic material formed by methylglyoxal in aqueous aerosol mimics – Part 1: Surface tension depression and light-absorbing products

“…To our knowledge, organosulfate formation by methylglyoxal in ammonium sulfate aerosols has not been observed previously, although Liggio et al (2005a, b) and Galloway et al (2009) identified organosulfate products in ammonium sulfate aerosols exposed to gas-phase glyoxal. Organosulfates have been identified in ambient aerosol (Gao et al, 2006;Iinuma et al, 2007;Gómez-González et al, 2008;Surratt et al, 2007Surratt et al, , 2008Russell et al, 2009;Lukács et al, 2009). Lukács et al (2009) observed that organosulfate mass concentrations were at a maximum for submicron aerosol size fractions, suggesting a link between organosulfate formation and heterogeneous SOA formation pathways.…”

“…Organosulfates have been identified in ambient aerosol (Gao et al, 2006;Iinuma et al, 2007;Gómez-González et al, 2008;Surratt et al, 2007Surratt et al, , 2008Russell et al, 2009;Lukács et al, 2009). Lukács et al (2009) observed that organosulfate mass concentrations were at a maximum for submicron aerosol size fractions, suggesting a link between organosulfate formation and heterogeneous SOA formation pathways. If C-N species form in this system, this could contribute to the nitrogen-containing aerosol organics which have been observed in ambient aerosol (Denkenberger et al, 2007;Aiken et al, 2008;Lin et al, 2009;Gilardoni et al, 2009).…”

Observed Relationships Between Cloud Droplet Effective Radius and Biogenic Gas Concentrations in Summertime Marine Stratocumulus Over the Eastern North Atlantic

“…Consequently, natural marine aerosols are largely comprised of sea‐salt, sulfate, and organic material generated from the oxidation of marine biogenic gases, predominantly DMS, and combinations therein (Davison et al., 1996; Frossard et al., 2014; Quinn et al., 2014). DMS is converted to CCN through multiple cascades of chemical pathways, many of which are only vaguely understood, but biogenic activity related to CCN production is indicated by elevated concentrations of DMS and methane sulfonic acid (MSA), which is a reaction product (Bardouki et al., 2003; Barone et al., 1995; Gaston et al., 2010; Hodshire et al., 2019; Lukács et al., 2009). The oxidation of DMS into sulfuric acid (H 2 SO 4 ) within the MBL and the condensation of this H 2 SO 4 onto the surface of the smallest aerosol particles may reduce the critical radius such that it transforms the particles into viable CCN at reasonable supersaturations.…”