ICARUS Chamber Experiment: Ziemann_20150220_Methyl nitrite/Nitric oxide/5-Decanol_Hydroxyl radical_DOS

Goals: Determine SOA yield of OH radical oxidation of the VOC Summary: Experiments were conducted in an 8.0 m^3 FEP Teflon environmental chamber in Boulder, CO, that was filled with clean, dry air [< 5 ppb of hydrocarbons and < 1% relative humidity (RH)] from two Aadco clean air systems and operated at ambient temperature (23 C) and pressure (630 Torr). The VOC was added to the chamber by evaporating a measured amount of the compound from a heated glass bulb into a stream of ultrahigh-purity (UHP) N2. Approximately 200 g/m^3 dioctyl sebacate (DOS) seed particles in UHP N2 were added from an evaporation?condensation apparatus. Known amounts of methyl nitrite and NO were prepared on a vacuum manifold using a calibrated glass bulb and absolute pressure gauge and then flushed into the chamber with UHP N2. Reactions were initiated by turning on blacklights that covered two walls of the chamber at 50% intensity (JNO2 = 0.37 per hour) for one hour. Photolysis of methyl nitrite created OH radicals with an average concentration of 4 x 107 molecules cm^-3, as determined from the measured decay of the VOC and estimated OH reaction rate constants. The VOC, methyl nitrite, and NO concentrations were 1, 5, and 5 ppm. Organization: Ziemann Lab Affiliation: University of Colorado, Boulder, Boulder, CO, USA Chamber: Janet (Chamber 1) Experiment Category: Gas phase chemical reaction, Photolysis, any phase, Aerosol formation Oxidant: Hydroxyl radical Reactants: Methyl nitrite, Nitric oxide, 5-Decanol Reaction Type: Photooxidation Relative Humidity: <1 Temperature: 23 Seed Name: DOS Pressure: 630