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


Name: 2014 FIXCIT Study_20140127_trans-beta-IEPOX/methyl nitrite_Hydroxyl radical_No Seed_Trans-beta-IEPOX + OH, moderate NO, dry, no seeds
Date: 2014-01-27

2014 FIXCIT Study

Seinfeld chambers

Experiment Set
FIXCIT experiments

Allow everyone to sample trans-b-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.

Today's experiment went largely according to plan. We successfully injected a large amount of IEPOX (we estimate 60-70 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.

Additional Notes
Initial conditions: ~60 ppbv IEPOX (as of 11:00am PST) ~200 ppbv CH3ONO 10% lights Instrument status: TD LIF - up PTRMS - up GTHOS - up LIF OHR - up 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 Timeline (UTC): 16:00: began filling bag with air; CF3O- CIMS on for background. 16:15: stopped filling bag. 16:22: began injecting IEPOX. 18:40: stopped IEPOX injection; began filling with air. 18:47: stopped filling bag. 19:00: all instruments began sampling. 21:00: all instruments stopped sampling. 21:04: began injecting CH3ONO. 21:16: stopped CH3ONO injection. 21:20: pulsed in air to mix. 21:30: all instruments began sampling. 22:04: 10% lights on. 25:04: lights off. 25:30: all instruments stopped sampling (except I- CIMS). 25:38: 100% lights on. 25:42: lights off. 25:54: started refilling far bag.

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: 7.3e6 (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
  • Alcohol
  • Epoxide
60 Parts Per Billion
methyl nitrite
  • NOx
200 Parts Per Billion

20140127_expTimeline.csv Timeline

UTC_hr Action
16:00 began filling bag with air; CF3O- CIMS on for background.
16:15 stopped filling bag.
16:22 began injecting IEPOX.
18:40 stopped IEPOX injection; began filling with air.
18:47 stopped filling bag.
19:00 all instruments began sampling.
21:00 all instruments stopped sampling.
21:04 began injecting CH3ONO.
21:16 stopped CH3ONO injection.
21:20 pulsed in air to mix.
21:30 all instruments began sampling.
22:04 10% lights on.
25:04 lights off.
25:30 all instruments stopped sampling (except I- CIMS).
25:38 100% lights on.
25:42 lights off.
25:54 started refilling far bag.

Light Flux Characterizations:
2013-12-16 (#19)
Particle Loss Characterizations:
2013-03-07 (#13)
Vapor Loss Characterizations:
2015-05-11 (#6)

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: