Experiment: Hildebrandt Ruiz Lab_20150706_ISOPRENE_Chlorine radical_Ammonium sulfate_C1_continuous Cl injection_neutral seed


Name: Hildebrandt Ruiz Lab_20150706_ISOPRENE_Chlorine radical_Ammonium sulfate_C1_continuous Cl injection_neutral seed
Date: 2015-07-06

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 0.42, and using neutral seed. Cl was continuously injected throughout the lights-on period with the total injected concentration reaching 94 ppb.

Neutral seed was injected with an initial seed surface area of 950 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
Initial Seed Concentration Value: 950
Seed Concentration Units:
Fuchs Adjusted Surface Area:
Condensation sink rate coefficient: 0
Reaction type:
Oxidant Name: Chlorine radical
Initial Oxidant Concentration Value: 94 (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) 40 Parts Per Billion

C1_timeline.csv Timeline

Time (HH:MM) Event description
11:27:50 UV Lights On
12:19:50 Injection of Chlorine Gas starts [Marker: Minute 52] - [Marker: time = 0]
14:06:03 INjection of chlorine stops [Marker: Minutes 149] - [Marker: Time = 41+6+60=107]
14:43:59 UV Lights Off [Marker: Minutes 186] [144 minutes after Cl2 injection]

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: