Experiment: 2014 FIXCIT Study_20140128_Isoprene/Methyl nitrite_Hydroxyl radical_No Seed


Name: 2014 FIXCIT Study_20140128_Isoprene/Methyl nitrite_Hydroxyl radical_No Seed
Date: 2014-01-28

2014 FIXCIT Study

Seinfeld chambers

Experiment Set
FIXCIT experiments

Isoprene moderate NO photooxidation with methyl nitrite and 10% lights, dry. To measure HCHO and glyoxal yields from isoprene + OH oxidation under moderate NO conditions (~1 ppbv). To continue the diagnosis of the OH artifact in GTHOS.

The experiment appeared to go well (and fast). Aerosol nucleation was observed. We added 25% RH during the lights on period, and at the end added ozone to probe the OH interference. Then we added NO to remove ozone.

Additional Notes
Instrument Status: TD LIF - up PTRMS - up GTHOS - up LIF OHR - Down, to conserve gas, and setup dilution. CRM OHR - up NO CL - up GLY LIP - up FOR LIF - up I/A CIMS - up NCIMS - up RHTO3 - up GC FID - up AMS - up TQC1 - up TQC2 - up TOFCIMS - up

Experiment Details


  • Gas phase chemical reaction
Temperature: 25
Relative Humidity: 5
Seeded Experiment: No
Fuchs Adjusted Surface Area:
Condensation sink rate coefficient: 5
Reaction type:
Oxidant Name: Hydroxyl radical
Initial Oxidant Concentration Value: 3e6 (molecules_per_cubic_centimeter)
RO2 Main Fate: NO
RO2 Lifetime: (Seconds)
Pressure: 750 Torr

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

Experiment Set Details

Name: FIXCIT experiments
Time format and units: Seconds past midnight
The Focused Isoprene eXperiment at the California Institute of Technology (FIXCIT) was a collaborative study at the atmospheric chambers of Caltech during January 2014. FIXCIT is the laboratory component of SOAS, and is aimed toward (1) better understanding the chemical details behind ambient observations relevant to the southeastern United States, (2) advancing the knowledge of atmospheric oxidation mechanisms of important biogenic hydrocarbons, and (3) characterizing the behavior of field instrumentation using authentic standards. A series of chamber experiments was conducted to investigate the oxidation of isoprene, α-pinene, methacrolein, pinonaldehyde, acylperoxy nitrates, isoprene hydroxy nitrates (ISOPN), isoprene hydroxy hydroperoxides (ISOPOOH), and isoprene epoxydiols (IEPOX). Pinonaldehyde and isomer-specific standards of ISOPN, ISOPOOH, and IEPOX were synthesized, enabling study of the oxidation mechanisms and instrument responses for these compounds.


  • Allen H. Goldstein UC Berkeley
  • William H. Brune Penn State University
  • Ronald C. Cohen UC Berkeley
  • Delphine K. Farmer Colorado State University
  • Manjula R. Canagaratna Aerodyne
  • Douglas R. Worsnop Aerodyne
  • Jose L. Jimenez University of Colorado Boulder
  • Frank N. Keutsch Harvard
  • Saewung Kim UC Irvine
  • Alex B. Guenther UC Irvine
  • John E. Mak SUNY Stonybrook
  • Geoffrey S. Tyndall NCAR
  • Denise D. Montzka NCAR
  • Andrew J. Weinheimer NCAR
  • Alam Hasson Fresno State


Principal investigators:

Paul O. Wennberg
Phone: 626 395 2447
E-mail: wennberg@caltech.edu
OrcID: 0000-0002-6126-3854

John H. Seinfeld
Phone: 626-395-4635
E-mail: seinfeld@caltech.edu
OrcID: 0000-0003-1344-4068

John D. Crounse
Phone: 626-395-8655
E-mail: crounjd@caltech.edu
OrcID: 0000-0001-5443-729X

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

Data Manager:

Tran B. Nguyen
Phone: 5307525987
E-mail: tbn@ucdavis.edu


Reactant Compound type Concentration Concentration units
Isoprene (6557)
  • Alkene
100 Parts Per Billion
Methyl nitrite (12231)
  • NOx
200 Parts Per Billion

20140128_expTimeline.csv Timeline

UTC_hr Action
16.33 Chamber T setpoint set to 25C
17 GTHOS sampled chamber background
17.5 Capped bag
17.67 Injected 10 ul isoprene
17.92 Stopped isoprene injection
18 All instruments began sampling
18.58 CH3ONO was injected (8.03 torr in 500ml bulb@22C)
19.08 10% lights on
21.5 Started humidifying bag
21.88 Stopped humidifying bag
22.08 Lights off
22.58 O3 addition started
23.97 O3 addition stopped
24.42 Added NO (4.5 min NO mixture @ 5 slm)
26.5 Started flushing the bag

Light Flux Characterizations:
2013-12-16 (#19)
Particle Loss Characterizations:
Vapor Loss Characterizations:

Chamber Details

Name: Seinfeld chambers
Volume in cubic meters: 22
Shape: Rectangular Prism
Surface area in cubic meters: 48
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: 40 ppt
Particle background in micrograms per cubic meter: < 0.01 ug/m3
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): 10
Temparature range (max degrees celcius): 45
Humidity Control: Yes
Humidity Measurements Recorded: Yes
Relative humidity range (min percent): 4
Relative humidity range (max percent): 90
Particle experiment capability: 1
Lights: Yes
Light source type(s): UV black lamps (350 nm centered)
Supplemental information: https://www.worldscientific.com/doi/abs/10.1142/9789813147355_0001
Additional Notes: