Goals:
To quantify SOA yield and gas-phase product yields (particularly of C10 nitrooxy-hydroperoxide and other organonitrates) from humid nighttime RO2+HO2-dominated NO3-initiated chemistry of b-ocimene.
Summary:
The chamber was humidified, after which H2O2, NO2, and O3 were injected in the chamber and allowed to equilibrate, forming NO3 and HO2. Ammonium sulfate seed particles were injected. Then b-ocimene was injected and decayed by simultaneous reaction with ozone and NO3. Gas phase organics were monitored by CF3O- CIMS (units: normalized counts), particle formation was monitored by SMPS, and RH/T/O3/NOx were monitored throughout.
O3/NOx data sometimes require post-correction not applied here, including subtraction of an ozone interference from H2O2 (1 ppm H2O2 is detected as about 12 ppb ozone) and correction for an in-line HEPA filter (see timeline for applicable timing) that scrubs about 10% of NO2 and 45% of ozone.
Organization: Nguyen Group
Lab Affiliation: UC Davis
Chamber: Tran's big bag of air
Experiment Category: Gas phase chemical reaction, Aerosol formation
Oxidant: Nitrate radical
Reactants: Nitrogen Dioxide, Ammonium Sulfate, Ozone, Hydrogen Peroxide, Ocimene
Reaction Type: Dark oxidation
Relative Humidity: 65
Temperature: 22
Seed Name: Ammonium sulfate
Pressure: approx 1 atm
