Environmental Molecular Sciences Laboratory

A DOE Office of Science User Facility

This page lives in the old site. Check out our new site here.

Chamber-based insights into the factors controlling epoxydiol (IEPOX) secondary organic aerosol (SOA) yield, composition, and

Abstract: 

We present measurements utilizing the Filter Inlet for Gases and Aerosols (FIGAERO) applied to chamber measurements of isoprene-derived epoxydiol (IEPOX) reactive uptake to aqueous acidic particles and associated SOA formation. Similar to recent field observations with the same instrument, we detect two molecular components desorbing from the IEPOX SOA in high abundance: C5H12O4 and C5H10O3. The thermal desorption signal of the former, presumably 2-methyltetrols, exhibits two distinct maxima, suggesting it arises from at least two different SOA components with significantly different effective volatilities. Isothermal evaporation experiments illustrate that the most abundant component giving rise to C5H12O4 is semi-volatile, undergoing nearly complete evaporation within 1 hour, while the second, less volatile, component remains unperturbed and even increases in abundance. We thus confirm, using controlled laboratory studies, recent analyses of ambient SOA measurements showing that IEPOX SOA is of very low volatility and commonly measured IEPOX SOA tracers, such as 2-methyltetrols and C5-alkene triols, result predominantly from artifacts of measurement techniques associated with thermal decomposition and/or hydrolysis. We further show that IEPOX SOA volatility continues to evolve via acidity enhanced accretion chemistry on the timescale of hours, potentially involving both 2-methyltetrols and organosulfates.

Citation: 
D'Ambro E., S. Schobesberger, C.J. Gaston, F.D. Lopez-Hilfiker, B.H. Lee, J. Liu, and A. Zelenyuk-Imre, et al. 2019. "Chamber-based insights into the factors controlling epoxydiol (IEPOX) secondary organic aerosol (SOA) yield, composition, and volatility." <i>Atmospheric Chemistry and Physics</i> 19, no. 17:11253-11265. PNNL-SA-142721. doi:10.5194/acp-19-11253-2019
Authors: 
Alla Zelenyuk-Imre,
Kurten
Theo;Gaston
Cassra Jayne;Wise
Matthew Eric;Surratt
Jason Douglas;Zelenyuk-Imre
Alla;Lopez-Hilfiker
Felipe Daniel;Li
Ziyue;Shilling
John E;Liu
Jiumeng;Thornton
Joel A;Hyttinen
Noora;Salo
Vili-Taneli;Wang
Jian;Hasan
Galib;Bell
David M;Cappa
Christopher;Schobesberger
Siegfried;Helgestad
Taylor M;Lee
Ben H;D'Ambro
Emma;Riedel
Theran P;Guenther
Alex B;Caylor
Ryan