Experiment: 2014 FIXCIT Study_20140103_ISOPRENE/nitric oxide/hydrogen peroxide_Hydroxyl radical_No Seed_Isoprene + OH, high NO, dry, no seeds


Name: 2014 FIXCIT Study_20140103_ISOPRENE/nitric oxide/hydrogen peroxide_Hydroxyl radical_No Seed_Isoprene + OH, high NO, dry, no seeds
Date: 2014-01-03

2014 FIXCIT Study

Seinfeld chambers

Experiment Set
FIXCIT experiments

High NO isoprene oxidation experiment. Interested mainly in working out chamber method for high-NOx condition with this many instruments.

Isoprene injection was conducted as the first step in the consideration of OH reactivity measurement. H2O2 injection proceeded as normally. 4.5 min NO injection was conducted to obtain 500 ppb NO level in the chamber. After approximately 30-45 minutes of sampling, instruments reported stable backgrounds so the UV lights were turned on. We have 50% lights on for the high-NOx conditions to slow down the isoprene decay. The bag was not very puffy when instruments started to sample for the background before lights on. For future runs, it might be better to fill the bag before background sampling started. This means the initial concentrations of all the precursors should be ~ 15% higher than the final desired values. I/A CIMS detected a signal at m/z 90 and they confirmed that this signal is oxalic acid. This might be resulted from the last experiment we did with HCHO injection involved.

Additional Notes
Instrument Status: TD LIF - up PTRMS - still down [waiting on a part] CRM OHR - up, but OHR too high to measure GTHOS - up LIF OHR - down [waiting on control board] NO CL - up GLY LIP - down [laser broken] FOR LIF - down I/A CIMS - up NCIMS - up RHTO3 - up GC FID - up AMS - up TQC1 - up TQC2 - up TOFCIMS - up Bag Additions: Isoprene, ~100ppb (10uL ISOP, 98% purity) H2O2, ~2ppm (120 uL 50% H2O2) NO, ~500ppb (4.5 min 500 ppm NO with 5L/min flow rate) Timeline (UTC, hh:mm): 15:45-Inject isoprene + mix 16:00-Sample chamber air to get a stable level 17:00-Inject H2O2 18:00-Inject NO 18:30-Sample for stable backgrounds 19:00-Lights on 24:20-Lights off and sample in the dark 25:00-Flush Far bag

Experiment Details


  • Gas phase chemical reaction
Temperature: 26
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: 2.4e6 (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
  • Alkene
100 Parts Per Billion
nitric oxide (145068)
  • NOx
500 Parts Per Billion
hydrogen peroxide (784) 2 Parts Per Million

20140103_expTimeline.csv Timeline

UTC_hr Action
15:45 Inject isoprene + mix
16:00 Sample chamber air to get a stable level
17:00 Inject H2O2
18:00 Inject NO
18:30 Sample for stable backgrounds
19:00 Lights on
24:20 Lights off and sample in the dark
25:00 Flush Far bag

Light Flux Characterizations:
2013-12-16 (#17)
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: