Experiment: Nguyen Group_20210322_ALPHA-PINENE/OZONE/hydrogen peroxide_Ozone_N/A

Experiment

Name: Nguyen Group_20210322_ALPHA-PINENE/OZONE/hydrogen peroxide_Ozone_N/A
Date: 2021-03-22

Organization
Nguyen Group

Chamber
Tran's big bag of air

Experiment Set
a-pinene nighttime chemistry

Goals
To quantify the nitrooxy-hydroperoxide yield and the SOA yield from nighttime RO2+HO2-dominated NO3-initiated chemistry of a-pinene by adding H2O2 + ozone + NO2 to the chamber. This experiment was predominantly to collect a filter to analyze the chemical content of pinene ozonolysis SOA by offline HRMS.

Summary
H2O2 and O3 were injected in the chamber and allowed to equilibrate. Then a-pinene was injected and decayed by reaction with ozone. The first pinene injection (100 ppb) didn't produce enough SOA for a good filter to analyze by HRMS, so more pinene was injected (150 ppb) over two periods until SOA produced was >200 ug/m3. Gas phase was monitored by CF3O- CIMS and particle formation by SMPS. After all injections, a filter was collected for offline HRMS analysis.

Experiment Details

Categories:

  • Gas phase chemical reaction
  • Aerosol formation
Temperature: 22
Relative Humidity: 5
Seeded Experiment: No
Fuchs Adjusted Surface Area:
Condensation sink rate coefficient: 5
Reaction type:
Oxidant Name: Ozone
Initial Oxidant Concentration Value: 100 (parts_per_billion)
RO2 Main Fate: Not Sure
RO2 Lifetime: (Seconds)
Pressure: 755 Torr

Data Sets

ID Instrument File  
2319 SMPS - bulk, wall loss corrected 210322_SMPS_corr.csv
2320 SMPS - bulk, uncorrected 210322_SMPS_uncorr.csv
2321 CF3O- CIMS: negative mode, raw spectra 210322_CIMS_neg.csv
2322 CF3O- CIMS: positive mode, raw spectra 210322_CIMS_pos.csv

Data Set plots
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Experiment Set Details

Name: a-pinene nighttime chemistry
Time format and units: HH:MM, local time
Description:
A series of experiments examining product yields and SOA formation from a-pinene + NO3 under conditions spanning a range of RO2 fates and under conditions designed to mimic the nighttime chemistry of the Southeast US in the summer. Two types of experiments are included: those in which the chemistry is initiated by addition of N2O5, which provides an easy NO3 source but tends to deviate from ambient conditions (i.e., no HO2 or ozone, and usually extremely high NO3 and/or RO2), and those in which the chemistry is initiated with O3 + NO2 + H2O2, which together provide conditions more closely resembling the ambient atmosphere at night (i.e., with HO2 and ozone in addition to NO3 and pinene) but have much more complex chemistry to untangle (simultaneous a-pinene + NO3, a-pinene + O3, and a-pinene + OH oxidation). For each experiment initiated with O3 + NO2 + H2O2, an additional control experiment without NO2 was run to account for this complex "background" (non-NO3) chemistry.

Collaborators:

  • Kelvin H Bates Harvard / UC Davis

Download

Download this Experiment (155.06 KB)

Contacts

Principal investigator:

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

Data Manager:

Kelvin H. Bates
E-mail: kelvinhbates@gmail.com

Reactants

Reactant Compound type Concentration Concentration units
ALPHA-PINENE (6654)
  • Alkene
  • Cycloalkene
 250 Parts Per Billion
OZONE (24823) 600 Parts Per Billion
hydrogen peroxide (784) 10 Parts Per Million

210322_timeline.csv Timeline

Time_HH:MM Action
9:30 Instruments on
9:42 CIMS on
9:46 Start H2O2 injection
10:30 Stop H2O2, start O3 injection (105 sec)
10:33 Stop injections
11:37 Inject a-pinene with mixing air pulses for 12 min
12:07 Start filter
14:50 Inject more pinene
15:15 Stop second pinene injection
15:37 Inject even more pinene
16:00 Stop third pinene injection
17:30 Instruments off
17:47 Filter stop

Citations
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Characterizations
Light Flux Characterizations:
(None)
Particle Loss Characterizations:
(None)
Vapor Loss Characterizations:
(None)

Chamber Details

Name: Tran's big bag of air
Volume in cubic meters: 10
Shape: Rectangular Prism
Surface area in cubic meters: 28
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:
Particle background in micrograms per cubic meter:
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):
Temparature range (max degrees celcius):
Humidity Control: Yes
Humidity Measurements Recorded: Yes
Relative humidity range (min percent):
Relative humidity range (max percent):
Particle experiment capability: 1
Lights: Yes
Light source type(s): UV broadband black lights (centered at 350 nm)
Supplemental information:
Additional Notes: 40-Watt, Osram/Sylvania 350nm black lights, 48” long, T12 fluorescent; 72 bulbs, 36 each on two facing walls, with UV-reflective siding on all walls. Lights are controlled via 6 panels (3 on the right wall - top, mid, bottom - and 3 equivalent on the left wall).