Experiment: Nguyen Group_20210114_2-Methylbut-3-ene-1,2-diol/Hydrogen Peroxide_Hydroxyl radical_Ammonium sulfate


Name: Nguyen Group_20210114_2-Methylbut-3-ene-1,2-diol/Hydrogen Peroxide_Hydroxyl radical_Ammonium sulfate
Date: 2021-01-14

Nguyen Group

Tran's big bag of air

Experiment Set
1,2-dihydroxy isoprene (DHI)

Product and SOA formation study on 2-methylbut-3-ene-1,2-diol (1,2-DHI) + OH, using wet (deliquesced) ammonium sulfate seeds at 50% RH. RO2 + HO2 pathway targeted.

1,2-DHI and H2O2 were injected, AS solution was atomized, and lights were turned on to initiate photooxidation. The CIMS died briefly partway through; it was only off for ~10 minutes but the signals appear to have changed a bit after restart. Note that the NOx and O3 monitors were sampling the room, not the chamber, until 11:00.

Experiment Details


  • Gas phase chemical reaction
  • Aerosol formation
Temperature: 22
Relative Humidity: 50
Seeded Experiment: Yes
Type of Seed: Ammonium sulfate
Initial Seed Concentration Value: 250
Seed Concentration Units: micrograms_per_cubic_meter
Fuchs Adjusted Surface Area:
Condensation sink rate coefficient: 50
Reaction type:
Oxidant Name: Hydroxyl radical
Initial Oxidant Concentration Value: 3e6 (molecules_per_cubic_centimeter)
RO2 Main Fate: HO2
RO2 Lifetime: (Seconds)
Pressure: 755

Data Set plots
Choose a file: Choose the X-Axis:

Experiment Set Details

Name: 1,2-dihydroxy isoprene (DHI)
Time format and units: HH:MM, local time
A series of experiments to investigate the gas-phase oxidation rate of 1,2-dihydroxy isoprene, its oxidation products via various RO2 pathways, and the effects of including seed (AS = ammonium sulfate) particles both on observed gas-phase products and on SOA formation.


  • Kelvin H Bates Harvard / UC Davis


Principal investigator:

Tran B. Nguyen
Phone: 5307525987
E-mail: tbn@ucdavis.edu
OrcID: 0000-0001-9206-4359

Data Manager:

Kelvin H. Bates
E-mail: kelvinhbates@gmail.com


Reactant Compound type Concentration Concentration units
2-Methylbut-3-ene-1,2-diol (185554)
  • Alcohol
  • Alkene
  • Diol
120 Parts Per Billion
Hydrogen Peroxide (784) 3 Parts Per Million

timeline_210114.csv Timeline

Time_local_HHMM Action
9:00 Start humidifying
9:12 SMPS on
9:28 CIMS on
9:45 Stop humidifying; start injections (H2O2 + AS seed + DHI)
10:00 Stop seed injection
10:15 All injections stopped; burst mixing air; let it equilibrate
11:00 100% lights on
12:23 CIMS computer died; ~10 minutes of data missing
12:40 Lights off
14:42 Start DNPH filter
14:53 Stop DNPH; instruments off

Light Flux Characterizations:
Particle Loss Characterizations:
Vapor Loss Characterizations:

Chamber Details

Name: Tran's big bag of air
Volume in cubic meters: 10
Shape: Rectangular Prism
Surface area in cubic meters: 28
Flow Mode: Batch
Flow through rate in liters per minute:
Body Material: Teflon
Body thickness: 2
Replacement date:
Replacement frequency: As needed
Cleaning method: Flushing with air Flushing with air with UV lights on Oxidation
o3 background: < 0.5 ppb
nox background:
Particle background in micrograms per cubic meter:
Air filtration method: Custom filtration canisters to remove NOx, hydrocarbons, water, particles, ozone, SOx from pressurized ambient air.
Mixing method: 1
Mixing method material: Pulsed air jets, manually actuated
Temparature Control: Yes
Temparature measurements recorded: Yes
Temparature range (min degrees celcius):
Temparature range (max degrees celcius):
Humidity Control: Yes
Humidity Measurements Recorded: Yes
Relative humidity range (min percent):
Relative humidity range (max percent):
Particle experiment capability: 1
Lights: Yes
Light source type(s): UV broadband black lights (centered at 350 nm)
Supplemental information:
Additional Notes: 40-Watt, Osram/Sylvania 350nm black lights, 48” long, T12 fluorescent; 72 bulbs, 36 each on two facing walls, with UV-reflective siding on all walls. Lights are controlled via 6 panels (3 on the right wall - top, mid, bottom - and 3 equivalent on the left wall).