Concentration-Dependent Kinetics of Cvoc-Ammonium Sulfate Brown Carbon Chromophores

The release of water-soluble volatile organic gases (VOCs) into the atmosphere results in chemical processes that occur within cloud droplets and atmospheric aerosols due to the aqueous setting. The oxidation of these volatile organic gases leads to the presence of secondary organic aerosol material (SOA). Glyoxal (GLYX) and methylglyoxal (MGLY), considered carbonyl-containing VOCs (CVOCs), have been studied as a precursor to the formation of SOAs. These water-soluble carbonyl compounds undergo Maillard-type browning reactions in the presence of ammonium salts due to its light absorbing qualities. Much is not known about the kinetics of these reactions. Herein, we discuss the potential modeling of these rate reactions across various concentrations of the CVOCs. To simulate atmospheric conditions, organics were mixed with ammonium sulfate and its light-absorbance tracked using a UV-vis spectroscopy over duration of time. The data was then modeled using Gaussian curves as its fitting parameters.