Experiment: 2014 FIXCIT Study_20140107_ISOPRENE/Methyl nitrite_Hydroxyl radical_No Seed_Isoprene + OH "slow chemistry" (isomerization), dry, 40C, no seeds
Experiment
Name: 2014 FIXCIT Study_20140107_ISOPRENE/Methyl nitrite_Hydroxyl radical_No Seed_Isoprene + OH "slow chemistry" (isomerization), dry, 40C, no seeds
Date: 2014-01-07
Organization
2014 FIXCIT Study
Chamber
Seinfeld chambers
Experiment Set
FIXCIT experiments
Goals
To make ppbv levels of HPALDs and associated compounds and observe their response in the suite of instrumentation. To photoxidize HPALDs and associated compounds and observe product species. Determination if HPALD (or associated cmpds) contributes toward interference on OH instrument.
Summary
Overall, the experiment went well. Initial NO levels in the high NOx bag were ~500 pptv which we believe was a result of connecting the GTHOS instrument to the bag shortly before starting the experiment. The HPALD compounds were formed overnight by photolyzing CH3ONO in the presence of isoprene under low levels of UV light, at 40C. By 10AM HPALD levels were ~1.3 ppbv as observed by CF3O- CIMS, and isoprene had decayed by a factor of 2. After the initial rapid NO decrease to stationary level (~70 pptv), NO remained stable over the low light portion of the experiment. After instrumentation began sampling the reaction products, the low level UV lights were turned off, and then temperature was ramped down to 25C, and then back up to 40C over the period of an hour. Next, 20% of chamber UV lights were turned on for 45 miniutes, and then 100% UV lights were illuminated for approx. 1.5 hrs. When the high level of UV lights were turned on, the AMS detected particle nucleation, and NO3- CIMS observed increases in several ion signals.
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 - down FOR LIF - down I/A CIMS - up NCIMS - up RHTO3 - up GC FID - up AMS - up TQC1 - up TQC2 - up TOFCIMS - up Timeline (UTC, hrs, January 7, 2014): 04:45 - Set chamber T setpoint to 40C 05:15 - NO, GTHOS, CF3O- sampled bag background 05:45 - Stopped sampling from bag. Injected CH3ONO into bag (500 ml bulb with 1.6 torr @ 295K) 05:56 - Inected 2.4 ul isoprene into bag 06:10 - Resumed sampling from bag (NO, GTHOS, CF3O-) 07:04 - Lights turned on (2 UV bulbs, mounted on north wall of chamber) 07:30 - GTHOS stopped sampling 18:00 - Most instruments started sampling 18:36 - Lights turned off 19:06 - Set chamber T setpoint to 25C 19:38 - Set chamber T setpoint to 40C 20:23 - Lights turned on (20% of lights) 21:08 - More lights turned on (100% lights) 22:44 - Lights turned off 23:45 - Stopped sampling, flush bag, Set chamber T setpoint to 25CExperiment Details
Categories:
- Gas phase chemical reaction
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: 4.1e4 (molecules_per_cubic_centimeter)
RO2 Main Fate: Autoxidation/Isomerization
RO2 Lifetime: (Seconds)
Pressure: 750 Torr
Data Sets
Data Set plots
Experiment Set Details
Name: FIXCIT experiments
Time format and units: Seconds past midnight
Description:
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.
Collaborators:
- 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
Contacts
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
20140107_expTimeline.csv
Timeline
| UTC_hr | Action |
| 04:45 | Set chamber T setpoint to 40C |
| 05:15 | NO/GTHOS/CF3O- sampled bag background |
| 05:45 | Stopped sampling from bag. Injected CH3ONO into bag (500 ml bulb with 1.6 torr @ 295K) |
| 05:56 | Inected 2.4 ul isoprene into bag |
| 06:10 | Resumed sampling from bag (NO; GTHOS; CF3O-) |
| 07:04 | Lights turned on (2 UV bulbs mounted on north wall of chamber) |
| 07:30 | GTHOS stopped sampling |
| 18:00 | Most instruments started sampling |
| 18:36 | Lights turned off |
| 19:06 | Set chamber T setpoint to 25C |
| 19:38 | Set chamber T setpoint to 40C |
| 20:23 | Lights turned on (20% of lights) |
| 21:08 | More lights turned on (100% lights) |
| 22:44 | Lights turned off |
| 23:45 | Stopped sampling; flush bag; Set chamber T setpoint to 25C |
Citations
Characterizations
2013-12-16 (#20)
Particle Loss Characterizations:
(None)
Vapor Loss Characterizations:
(None)
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: