Experiment: 2014 FIXCIT Study_20140113_ALPHA-PINENE/nitric oxide/OZONE/formaldehyde_Nitrate radical_Ammonium sulfate_HO2 fate, dry RH, seed added at end


Name: 2014 FIXCIT Study_20140113_ALPHA-PINENE/nitric oxide/OZONE/formaldehyde_Nitrate radical_Ammonium sulfate_HO2 fate, dry RH, seed added at end
Date: 2014-01-13

2014 FIXCIT Study

Seinfeld chambers

Experiment Set
FIXCIT experiments

Study alpha-pinene + NO3 chemistry by injecting 150 ppb NO2 & 75 ppb O3, plus HCHO. Run the experiment so as to optimize for the formation of the nitrooxyhydroperoxide (MW = 231), which we detected during SOAS and to prevent the dominance of RO2 + RO2 reactions. We will see if we can better understand the gas phase nitrate yields from alpha-pinene nighttime chemistry when we run the experiment in a more atmospherically relevant way than has been done in the past. We will also inject ammonium sulfate seed at the end of the experiment to see, which and to what degree, the gas phase nitrates partition into the particle phase.

We formed a very high yield of nitrooxyhydroperoxide. In fact most of the other masses detected by the CF3O- CIMS were significantly smaller. After the nitrooxyhydroperoxide signal began to level out, we ramped the temperature to determine if any species came off the walls. The signal for the nitrooxyhydroperoxide and other signals did increase, but not substantially. We then cooled the chamber and injected seed. There was uptake seen by the AMS (~10 ug/m^3). At the very end we turned on lights, and saw the nitrooxyhydroperoxide signal increase instead of decay. There was still alpha-pinene left unreacted at this point as confirmed via the PTR-MS. O3 increased to around ~500 ppb over only 30 minutes after lights turned on, so likely this provided enough NO3 to be competitive with OH.

Additional Notes
TD LIF up; PTRMS up; GTHOS up; LIF OHR off due to formaldehyde interference; CRM OHR up; NO CL up; GLY LIP down; FOR LIF off due to high formaldehyde concentration, I/A CIMS up, NCIMS up; RHTO3 up; GC FID off due to current column not detecting alpha-pinene; AMS up; TQC1 up; TQC2 up; TOFCIMS up

Experiment Details


  • Gas phase chemical reaction
Temperature: 25
Relative Humidity: 5
Seeded Experiment: Yes
Type of Seed: Ammonium sulfate
Initial Seed Concentration Value:
Seed Concentration Units:
Fuchs Adjusted Surface Area:
Condensation sink rate coefficient: 5
Reaction type:
Oxidant Name: Nitrate radical
Initial Oxidant Concentration Value: 4e8 (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: 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
30 Parts Per Billion
nitric oxide (145068) 150 Parts Per Billion
OZONE (24823) 75 Parts Per Billion
formaldehyde (712)
  • Aldehyde
8 Parts Per Million

20140113_expTimeline.csv Timeline

Time (America/Los_Angeles) Action
8:25 Start NO/CO span 2|20|off|35.0
8:40 NO 84.96 Nox 87.4 CO 16.46
Start GPT span 2|20|0.7|35.0
8:55 NO 61.52 Nox 86.91 CO 16.46
Start O3 span 2|20|0.7|off
9:29 O3 35.89
Start E-W-Z sampling
9:30 Fill air off
9:54 Air Handler on Heater on
9:32 Inject 100uL PFH into both bags
9:46 Inject 380uL H2O2 to both bags at 50~70C
10:14 Inject 20uL DEGEE to both bags at 71~95C
11:00 Mix E-W bags for 10 mins
11:14 Close valve 14
11:15 Inject (2.532-0.025) torr x 0.253L NO to East bag
11:23 Mix East for 1 min
GC2 sampling until 11:10
11:53 Only see 4ppb on East
Inject (1.659-0.03) torr x 0.253L NO to East bag
12:03 Mix East for 1 min
12:15 BLs on, Heater off
15:05 AMS on East
Valve not open until 17:50
18:47 BLs off, Air Handler off

Light Flux Characterizations:
Particle Loss Characterizations:
2013-03-06 (#12)
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: