Experiment: Hildebrandt Ruiz Lab_20170617_ISOPRENE_Chlorine radical_Ammonium sulfate + Sulfuric acid_A7_acidic seed


Name: Hildebrandt Ruiz Lab_20170617_ISOPRENE_Chlorine radical_Ammonium sulfate + Sulfuric acid_A7_acidic seed
Date: 2017-06-17

Hildebrandt Ruiz Lab

LHR Chamber

Experiment Set
Isoprene + Cl

To calculate SOA yield from Cl-initiated photo-oxidation of isoprene at a VOC:Cl2 ratio of 0.98, and using acidic seed.

Acidic seed was injected with an initial seed surface area of 2700 um2/cm3, followed by a Cl2 injection out of a gas cylinder, and the isoprene injection using a heated glass bulb. Temperature was kept at 25C for the whole duration of the experiment, while RH was kept at less than 10%.

Experiment Details


  • Gas phase chemical reaction
  • Volatility and partitioning
  • Aerosol formation
Temperature: 25
Relative Humidity: 0
Seeded Experiment: Yes
Type of Seed: Ammonium sulfate + Sulfuric acid
Initial Seed Concentration Value: 2700
Seed Concentration Units:
Fuchs Adjusted Surface Area:
Condensation sink rate coefficient: 0
Reaction type:
Oxidant Name: Chlorine radical
Initial Oxidant Concentration Value: 100 (parts_per_billion)
RO2 Main Fate: Not Sure
RO2 Lifetime: (Seconds)

Data Set plots
Choose a file: Choose the X-Axis:

Experiment Set Details

Name: Isoprene + Cl
Time format and units:
Environmental chamber experiments were carried out under low-NOx conditions with isoprene and chlorine as primary VOC and oxidant sources. Secondary organic aerosol yields were calculated upon complete isoprene consumption. Formation of particulate organochloride was tracked using an ACSM. A high-resolution time-of-flight chemical ionization mass spectrometer was used to determine the molecular composition of gas-phase species using iodide–water and hydronium–water cluster ionization.


  • Dongyu S. Wang University of Texas at Austin, now at Paul Scherrer Institute in Switzerland
  • Lea Hildebrandt Ruiz University of Texas at Austin


Principal investigator:

Lea Hildebrandt Ruiz
E-mail: lhr@che.utexas.edu
OrcID: 0000-0001-8378-1882

Data Manager:

Lea Hildebrandt Ruiz
E-mail: lhr@che.utexas.edu


Reactant Compound type Concentration Concentration units
ISOPRENE (6557) 98 Parts Per Billion

A7_timeline.csv Timeline

Time (HH:MM) Event description
9:26 Starting FIGAERO blank routine
9:36 IMR Pressuure is too low
9:36 Adjusting IMR pressure
10:05 Injecting 4 ul of isoprene, 2 LPM CA
10:11 IMR pressure is unstable depite usign the imr controller
10:21 Sampling gas-phase
10:38 Start of Cl2 injection, 101 ppm at 2 LPM for 5 mins
10:43 Injection has finished
10:56 UV on (5/5)
11:57 UV off (0/5)
12:29 Preparing to set up figaero filter collection
12:34 Filter collection starts
13:19 Figaero collection finished, preparing to go into desorption mode
13:22 Starting FIGAERO desorption routine
15:12 End of 2nd desorption round, preparing for 2nd filter collection
15:14 Sampling gas-phase
15:14 Start of 2nd filter collection
15:29 preparing to change voltage
15:52 Sampling gas in water mode
16:00 FIGAERO collection stopped, preparing to start desorption
16:02 Looking at a collected filter
16:07 Starting FIGAERO desorption routine
18:00 Prepare to end the desorptions and CIMS operations for the day.

Light Flux Characterizations:
Particle Loss Characterizations:
Vapor Loss Characterizations:

Chamber Details

Name: LHR Chamber
Volume in cubic meters: 8.92
Shape: Rectangular Prism
Surface area in cubic meters: 26.4
Flow Mode: Batch
Flow through rate in liters per minute:
Body Material: Teflon
Body thickness: 5.0
Replacement date: 2018-06-15
Replacement frequency: As needed
Cleaning method: Flushing with air Flushing with air with UV lights on Oxidation
o3 background:
nox background:
Particle background in micrograms per cubic meter: < 10 counts/cm3
Air filtration method: NA
Mixing method: 0
Mixing method material:
Temparature Control: Yes
Temparature measurements recorded: Yes
Temparature range (min degrees celcius): 5
Temparature range (max degrees celcius): 50
Humidity Control: No
Humidity Measurements Recorded: Yes
Relative humidity range (min percent): 0
Relative humidity range (max percent): 85
Particle experiment capability: 1
Lights: Yes
Light source type(s): UV-A Blacklight
Supplemental information:
Additional Notes: