Chemical characterization of organosulfates in secondary organic aerosol derived from the photooxidation of alkanes

Abstract

Abstract. We report the formation of aliphatic organosulfates (OSs) in secondary organic aerosol (SOA) from the photooxidation of C10–C12 alkanes. The results complement those from our laboratories reporting the formation of OSs and sulfonates from gas-phase oxidation of polycyclic aromatic hydrocarbons (PAHs). Both studies strongly support the formation of OSs from the gas-phase oxidation of anthropogenic precursors, as hypothesized on the basis of recent field studies in which aromatic and aliphatic OSs were detected in fine aerosol collected from several major urban locations. In this study, dodecane, cyclodecane and decalin, considered to be important SOA precursors in urban areas, were photochemically oxidized in an outdoor smog chamber in the presence of either non-acidified or acidified ammonium sulfate seed aerosol. Effects of acidity and relative humidity on OS formation were examined. Aerosols collected from all experiments were characterized by ultra performance liquid chromatography coupled to electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-QTOFMS). Most of the OSs identified could be explained by formation of gaseous epoxide precursors with subsequent acid-catalyzed reactive uptake onto sulfate aerosol and/or heterogeneous reactions of hydroperoxides. The OSs identified here were also observed and quantified in fine urban aerosol samples collected in Lahore, Pakistan, and Pasadena, CA, USA. Several OSs identified from the photooxidation of decalin and cyclodecane are isobars of known monoterpene organosulfates, and thus care must be taken in the analysis of alkane-derived organosulfates in urban aerosol.

Biogenic, urban, and wildfire influences on the molecular composition of dissolved organic compounds in cloud water

“…Monoterpene-derived organosulfates and organonitrates (Surratt et al, 2008) were observed in the cloud water during all air mass influences, similar to previous cloud water studies (Boone et al, 2015;Pratt et al, 2013). Notably, long-chain, alkane-derived organosulfates (Riva et al, 2016) were observed in cloud water when urban influence was present. Future work comparing cloud water composition with aqueous aerosol is needed to isolate in-cloud processes from aqueous-aerosol processes.…”

“…A fraction of the CHOS compounds, unique to sample B1, were characterized by low O : C (0.05-0.25) and H : C (0.6-1.2) ratios, similar to previous cloud water observations by Zhao et al (2013). Notably, aliphatic organosulfate species derived from photooxidation of long-chain alkane precursors (C 10−12 ), including dodecane, cyclodecane, and decalin, recently observed in laboratory and urban ambient aerosol studies (Riva et al, 2016;Tao et al, 2014), were detected in the B1 cloud water Figure 4. NOAA HYSPLIT 144 h (6-day) backward air mass trajectory (white line, with 1-day resolution, shown as black dots) and corresponding cloud water molecular composition, shown as compound-type number fractions during the wildfire event (sample C1).…”

Importance of Sulfate Radical Anion Formation and Chemistry in Heterogeneous OH Oxidation of Sodium Methyl Sulfate, the Smallest Organosulfate

“…The detection of organosulfates in 10 laboratory studies have been complemented by a number of field observations, which confirm the presence of organosulfates in atmospheric particles (Budisulistiorini et al, 2015;Chan et al, 2010;Darer et al, 2011;Frossard et al, 2011;Froyd et al, 2010;Hawkins et al, 2010;Hettiyadura et al, 2015;Huang et al, 2015;Iinuma et al, 2007;Kuang et al, 2016;Olson et al, 2011;Rattanavaraha et al, 2016;Riva et al, 2016;Shakya and Peltier, 2013;Stone et al, 2012;Surratt et al, 2007Surratt et al, , 2008Surratt et al, , 2010. While the abundance, composition, and formation mechanisms have extensively been investigated, there is comparably little work understanding how organosulfates chemically transform in the atmosphere.…”

Quantification of known and unknown terpenoid organosulfates in PM10 using untargeted LC–HRMS/MS: contrasting summertime rural Germany and the North China Plain

“…epoxides) and an acidic sulfate aerosol (Iinuma et al 2007a(Iinuma et al , 2007bSurratt et al 2008Surratt et al , 2010. Several laboratory studies focussed on OS formation mechanisms from a variety of biogenic as well as anthropogenic volatile organic compounds, which include isoprene (Riva et al 2016b;Schindelka et al 2013;Surratt et al 2010), monoterpenes (MTs, Iinuma et al 2007aIinuma et al , 2007bSurratt et al 2008), pinonaldehyde (Liggio and Li 2006), sesquiterpenes (SQTs, Chan et al 2011), unsaturated aldehydes (Shalamzari et al 2016), and polycyclic aromatic hydrocarbons as well as alkanes (Riva et al 2016a). Moreover, direct formation of OSs from reactions of gaseous SO 2 with fatty acids (Passananti et al 2016) and limonene-derived Criegee intermediates were reported (Ye et al 2018).…”

“…Previous studies on the detection and identification of OSs have mostly relied on mass spectrometry (MS) in combination with electrospray ionisation (ESI) (Iinuma et al 2007a; Kristensen and Glasius 2011;Riva et al 2016a;Surratt et al 2008). In contrast to the rather harsh ionisation methods, such as electron ionisation, ESI typically yields major signals for protonated ([MþH] þ ) or deprotonated ([M-H] À ) molecular ions with positive and negative polarity respectively.…”