ICARUS Chamber Experiment: 2014 FIXCIT Study_20140127_trans-beta-IEPOX/methyl nitrite_Hydroxyl radical_No Seed_Trans-beta-IEPOX + OH, moderate NO, dry, no seeds

Goals: Allow everyone to sample trans-beta-IEPOX for an intercomparison of sensitivities and a look at possible interferences; observe the products of IEPOX + OH oxidation, which we expect to include hydroxyacetone, glycolaldehyde, glyoxal, methylglyoxal, and C4H8O3 and C4H6O3 compounds. Summary: Today's experiment went largely according to plan. We successfully injected a large amount of IEPOX (we estimate 60 to 70 ppbv) over the course of 2.5 hours. Following the injection, the CF3O- CIMS saw significant wall loss, totaling ~25% in 3 hours. This is similar to the wall loss observed during IEPOX experiments last summer (~7%/hour in the same bag with high levels of HNO3), which may imply that the walls are currently highly acidified. When lights were turned on, IEPOX reacted quickly; ~50% of the IEPOX remaining when lights were turned on reacted away within an hour, and a further 20% was lost in the next two hours. The CF3O- CIMS observed many of the expected oxidation products, including hydroxyacetone, glycolaldehyde, C4H8O3, C4H6O3, and C5H8O3. Glyoxal did see an increase in signal, though they also had high noise levels. O3 reached 150 ppbv by the end of the experiment, and AMS did not see significant nucleation or aerosol growth. Organization: 2014 FIXCIT Study Lab Affiliation: California Institute of Technology Chamber: Seinfeld chambers Experiment Category: Gas phase chemical reaction Oxidant: Hydroxyl radical Reactants: trans-beta-IEPOX, methyl nitrite Reaction Type: Photooxidation Relative Humidity: 5 Temperature: 25 Pressure: 750 Torr