READ AND REVIEW ANY APPLICABLE MANUFACTURER/VENDOR SAFETY INFORMATION BEFORE
DEVELOPING STANDARD OPERATING PROCEDURE AND PERFORMING WORK.
Date Modified: April 15, 2020 PI Name: Sergey Nizkorodov
Name of Work Unit: Aerosol Photochemistry Group
Standard Operating Procedure (SOP) for
Generating, Monitoring, and Collecting SOA with the 5 m 3 Photochemical Chamber
#1 Scope of Work/Activity: Describe the experiment purpose/scope.
Identify all apparatus that will be used, and associated requirements.
List special equipment (X-ray generators, lasers, furnaces, etc.) that will be used for the project.
Identify measurement and test equipment, apparatus operating conditions,
Include process flow diagrams, pressures, and required maintenance procedures as appropriate.
The system consists of:

Rectangular prism bag (6 m
3
volume) made out of 5 mil PTFE material

20 m
3
black acrylic external chamber with silicon gaskets

40 UV-B broadband lamps (310 nm center wavelength)

SMPS

NOy monitor

Ozone monitor

Humidity/Temperature probe

Fan

Nafion humidifier with temperature-controlled water circulator
Test equipment needed:

None
#2 Specific Safety and Environmental Hazards: State the specific hazard and consequences if procedure not followed to person, environment, or property.
Exposure to UV radiation is mutagenic, exposure to O
3
,NOx and particles produced while chamber is flushing or running is hazardous
#3 Describe in detail how the hazards will be controlled. a. Identify the Engineering Controls (e.g. interlocks, shielding), Standard Operating Procedures, or
Personal Protective Equipment (e.g. respirators, gloves;) that will be employed to reduce hazards to acceptable levels.
Engineering controls include:

Chamber is attached to high-flow vents for flushing

Purge tube can be closed with a manual shut off valve

Black acrylic exterior prevents exposure to oxidants, particles and UV radiation

NOy monitor exhaust is directed into vents

O
3
monitor exhaust is returned to the chamber b. Address emergency shutdown procedures.

In case of overpressure resulting in the contents of the PTFE bag escaping, close the enclosure door and flush thoroughly with dry air
#4 Designated Area: Indicate the designated area for performing this process in the laboratory.
Chamber is permanently situated in RH385, and is not movable.

#5 Personal Protective Equipment (PPE): State the personal protective equipment selected and required. Examples: safety spectacles, work gloves, respiratory protection, steel toe shoes.
Personal protective equipment includes:

UV eye protection and clothe that fully covers the skin must be worn if opening the chamber door when the lights are on.

Never enter the enclosure with the UV lights on.
#6 Important Steps to Follow: List the specific sequence staff should follow to avoid hazard.
Refer to the attached directions for the start up and power down procedures. Consult instrument manuals for detailed instructions.
#7 Emergency First Aid Procedures: a.
Describe immediate medical treatment required in case of personnel exposure.
-Complete online incident report form at www.ehs.uci.edu
If someone inhales too much oxidant:

Remove the person to an area with clean air.

Seek medical attention if applicable.
#8 Training & Competency Requirements: Describe necessary training and demonstration of competency for performing the hazardous operation.
Everyone operating the chamber must:

Read this SOP

Review manuals for SMPS, NOy and O
3
monitor

Beginners must first shadow an experienced user, and then operate the chamber under close supervision, before attempting to run it themselves.
#9 Identify waste stream and disposition of unused stock of chemicals
List concentrations and amounts of hazardous wastes or emissions and control measures.
Additional guidelines regarding hazardous waste at : http://www.ehs.uci.edu/programs/enviro/
Low levels of O
3
and NOx emissions are produced and may be removed with activated charcoal.
#10 Decontamination and spill clean-up procedures
In the event the chamber bag is replaced the old bag can be disposed of in a regular trash.
As the Principal Investigator, it is your responsibility to ensure that all individuals listed in this protocol is taught correct procedures for the safe handling of hazardous materials involved in this study. It is also your responsibility to assure that your personnel attend Lab Core Safety Training and other applicable safety training courses.

Both PI and all persons associated with the protocol must sign the following acknowledgement:
I have read, asked questions, and understand the hazards of and safe working procedures for the activity/materials described herein.
PI Signature: DATE
Other Personnel:
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DATE
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3
Last updated on April 15, 2020
PPE required for chamber use:

Gloves, lab coat, lab glasses, closed shoes

Hood for preparing chemicals

Toxic gas cabinet for storing toxic gases (NO standard)
Teflon chamber Stainless steel tubes
Injection Port
Connection ports to: dry air, SMPS, O
3
monitor,
NOy monitor
Collection port to PTRMS,
SMPS or Filter/MOUDI
Electric Fan
Vent Tube
Relative
Clamp + Tape
(to close off)
Humidity Probe
Sleeve
To vent
Vent Valve
Figure 1: Schematic drawing of 5 m
3
Teflon chamber and components. The chamber is surrounded by a 20 m
3 black acrylic enclosure (with silicone gaskets) and ca.
40 UV lamps. Note: not even close to scale.
This SOP is for generating SOA under HUMID, high-NOx, photochemical conditions with the following instruments monitoring the reaction: a) Proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) – monitors volatile organic compounds (no alkanes, CO, CO
2
, CS
2
, etc…) b) Scanning mobility particle sizer (SMPS) – monitors particles (diameters, number count, and number/mass densities). c) NO- Dif- NOy analyzer – monitors NO and [NOy-NO] (NO
2
, particulate nitrates, etc…) d) O
3
analyzer – monitors ozone e) Vaisala probes – monitors temperature and RH (read-out on the front of chamber near light switches)
***If you don’t need one or more of these conditions, just skip the desired steps***
Flushing the Chamber:
1) Make sure the glass bubbler in the injection port is clean. You may need to clean it with acetone and air dry.
2)
The chamber should be connected to a dry purge air source (Parker FTIR purge gas generator) by a 3/8” plastic tube entering the back. The connection to the chamber should be labeled “AIR IN.” When the chamber is being flushed the large valve on the vent tube must be OPEN. The valve is located inside the chamber enclosure.

3) The flow rate range is 0-100 standard liters per minute (SLM) uncalibrated. Flushing the chamber of all
VOC should take at least overnight (>10 hr) at high (60 SLM) flush rates. When not in use, lower the flush flow rate to < 20 SLM.
4) When you are done with flushing, CLOSE the vent tube valve and shut off air flow. The chamber is now ready for experiments in dry air. Steps to humidify the air in the chamber are described below.
Turning ON the Instruments:
Before starting experiments, the instruments have to warm up.
1) PTR-MS: a.
The stainless steel tube that goes to the PTRMS and SMPS (and later to the collection) should be split by an Ultratorr Tee. b.
To start the PTRMS, open the “PTR Manager” program by double clicking the icon located on the desktop. This program controls the pressures and flows in the PTRMS. Go to the “Control” tab, click on “Operation” and make sure the instrument is on Operation Mode. Check the front of the instrument to see that the Drift pressure is around 2.2 mbar, the Foreline pressure is < 5 mbar, the TOFlens pressure is ~ 1 x10
-5
mbar, and the TOF pressure is ~ 1 x10
-7
mbar. The sample flow should be 50-200 sccm. c.
Open the “TPS Controller” program from the desktop icon. This program controls all the voltages applied in the PTRMS. Click the “Initialize” button on the top left. Go to the “Setting
Files” tab and click on a file called “UCI_12_6_2010.set” or an updated version. Click on the
“All Voltages” button on the top. d.
Wait > 30 minutes for the voltages to stabilize. e.
Make sure the inlet of the PTRMS is connected to the chamber with a Teflon tube (do not use conducive tubing – it introduces significant contamination in the mass spectrum).Be careful not to pull on or kink the small yellow PEEK (a heat-resistant plastic) tube in any way- it is advisable to clamp the tubes in place so that you don’t accidentally pull on the PEEK tube. f.
DO NOT TURN OFF THE PTR MANAGER THROUGHOUT USE.
2) O
3
Analyzer: a.
Click the ON switch at the front of the instrument. b.
Wait >30 minutes (manual says 90 minutes, but 30 is fine).
3) NOy Analyzer: a.
Click the ON switch at the front of the instrument. b.
Plug in the external pump (white cord) – you should be able to hear it if it’s on. c.
Turn on the bypass pump. Make sure it reads 1.5 LPM on both sides. d.
Check that the inlet is connected to the chamber. e.
Wait >30 minutes (manual says 90 minutes, but 30 is fine).
4) The Computer connected to the O
3
and NOy monitor a.
Turn the computer and monitor on. Click on “Thermo iPORT” icon on the desktop. Click on
“Connect” button (with cyan blue phone icon) or go to the “Comm” tab and click “Connect.”
You should be able to see the readings from the NOy and O
3
analyzer when they are warmed up.
5) SMPS: a.
Click the ON switches at the back of the DMA (top) and the CPC (bottom). b.
Make sure the inlet of the DMA is connected to the chamber with conductive tubing (the black silicon-based tubing works well –do not use Teflon). c.
Make sure the 1-butanol bottle connected to the CPC is not empty. d.
Wait > 20 minutes.

Introducing Relative Humidity:
Nafion Humidifier
Connect to “Air IN” port
37.3
Air IN
Water Circulator
Purge
Gas Figure 2: Connection at the back of the chamber to Nafion humidifier.
While the instruments are warming up – introduce the desired RH.
1) Make sure the valve in the vent tube for the chamber is OPEN.
2) Turn on the fan a.
On the front of the chamber, underneath the light switches, there is an electrical box with a button. This is the “ON/OFF” button for the fan (when on the button is lit up).
3) Turn on the Julabo water heater/circulator a.
There is an ON switch at the right hand side of the water circulator. b.
Make sure there is enough water in the circulator, fill it up with Nanopure or distilled water ½” from the top. c.
Set the temperature to approximately 30 degrees Celsius using the temperature control panel
(chances are it’s already set.) Note: there are two temperature controls (T1 and T2) you only need one of them. d.
Turn off the flow on the purge gas generator. Connect the 3/8” plastic tubing to the black conductive tubing that is attached to the Nafion humidifier (Fig. 2). Attach the other end of the connective tubing to the “Air IN” port of the chamber. e.
Turn the flow on the purge gas generator to 40-60 SLM. The chamber will start humidifying as shown on the RH read-out panel in front of the chamber.
4) CLOSE the chamber vent , shut off air flow, and turn off water circulator when desired RH is reached.
***Proceed to these next steps if the chamber has reached the desired RH and the instruments have warmed up. ***
Program the SMPS and Start Collecting Data
1)
Click on the “Aerosol Instrument Manager” icon on the laptop monitor to start the software.
2)
Go to the “File” tab, click on “New.” Choose the directory for the file, and name it according to your preference. The naming mechanism YYYY_MM_DD_EXPERIMENT works well if you don’t know what to name it.
3)
Now the “SMPS Properties” window will pop up. Enter in the following information: a.
Under “Hardware Settings” i.
Classifier model “3080” ii.
DMA “3081” iii.
Impactor Type “0.071 cm” iv.
CPC model/flow rate “3775 LOW” v.
DMA flow rate (LPM): Sheath “3.0” and Aerosol “0.3” b.
Press “Set to max range” button next to DMA flow rate

i.
You should see “Size range: 14.3-673.2nm” and “Voltage range: 10-9591V” c.
Scan time, up 120, retrace 15. d.
Click on the second tab “Scheduling” i.
Click on “Repeat every” and enter in anything from 1-5 minutes. 4 minutes works well for me.
4) Physically set the sheath flow by using the large black dial on the DMA to press “Menu” on the DMA.
Press on “Sheath Flowrate” and adjust the dial to read 3.0 LPM. Then press “Exit.”
5)
Click on the green “Start” button to start acquiring data with the set time interval.
Program the PTRMS and Start Collecting Data
1)
Click on the “TofDaqRec” yellow icon on the desktop.
2) Click on the the “DAQ” button on the top toolbar and go to the “Files/Paths” tab. a.
On the data directory, choose your own folder (or make one) b.
For the file name, the system has set up a <timestamp>_filename.h5 naming mechanism. It’s best to use this because every time you start/stop the program it generates a new file so the timestamp keeps the filenames unique. Delete all files you are not using (e.g. mass calibration)!
Close the DAQ window. c.
Don’t mess with the timing if you don’t know what you’re doing!!! d.
You will see two screens: the top one shows the updated and averaged mass spectrum and the bottom one shows the time-dependent traces of selected VOC. In order to select VOC, find them in any of the 5 scroll-down menus. It’s a good idea to choose H
3
18
O
+
as one of your traces because this monitors the primary ion (you want this trace to be stable). e.
Click the start button at the top left. Check the “Log scale” box on the bottom of the top window to enhance the intensities of the smaller peaks. f.
Click on “average” box on the right toolbar and click off “combined.” Wait a few minutes and zoom in to the 21 peak using your magnifier tool and check the “peak parameters” box at the bottom of the top screen. If the peak is pretty close to 21.0235 m/z then skip calibration. If not, to do calibration, you have to stop the data acquisition so click “stop.” Highlight the 21 peak and click on “set” button on the right toolbar. Enter in the following values for the respective peaks
(press “close” after each one, and “calibrate” after the last one): i.
21.0235 m/z ii.
29.9980 m/z iii.
59.0497 m/z iv.
Click “calibrate” and restart data collection. Delete the file you had created before. You are now collecting data – the program will stop only when the set time runs out (7 hours or so) or you stop it.
Introduce NOx
1) I like to ensure the introduced NOx is well-mixed before it’s inhaled by the NOy analyzer. So I temporarily open the inlet of the NOy analyzer to room air and plug the other end (coming from the chamber) before adding NO.
2) The chamber is connected to a 5000 ppm NO in N
2
standard gas cylinder located in the gas hood in the back of the room (Matheson gas products). The cylinder is connected to a 0-100 standard cubic centimeters per minute (sccm) calibrated mass flow controller (MFC) with digital read-out. a.
Make sure the MFC switch is on “Close.” Turn the round dial to “Set” and use the dial to set 85 sccm (this set flow is equal to 100 sccm actual flow according to a calibration I did on 1/7/2010).
Turn the round dial to “Flow.” b.
Open the NO cylinder and the regulator. c.
Flipping the switch to “Control” now will turn on the flow to the chamber according to the set flow rate on the MFC.
Flipping the switch to “Purge” will open up the cylinder to the

chamber at a very high flow rate that exceeds the one you set – do not do it unless NO cylinder is CLOSED. Read step (d) first before you proceed. d.
Before you turn on the flow, make sure you know how much you are adding. Just from experience, the mass flow is not linear. Here are some recommendations: i.
300 ppb NO = 4.0 minutes flow. Then shut off the cylinder and regulator. Then flip the switch to “purge” to get rid of all the NO in the gas lines. The MFC read-out should go to zero. ii.
600 ppb NO = 9.0 minutes flow. Then shut off cylinder and purge as before.
3) Let the air mix in the chamber for ~ 5 minutes and reconnect the chamber to the NOy analyzer. You should see approximately the desired reading of NO and possibly some NO
2
.
Introduce OH Precursor and Hydrocarbon
1) Use the injection port (Fig. 1) to inject your OH precursor (H
2
O
2
, isopropyl nitrite, etc.) For 250 ppb of hydrocarbon, I add 2 ppm of 30% w/w H
2
O
2
which equates to roughly 40 μL. The injection port is also hooked up to a flow controller (0-10 SLM). For introducing 40 μL H
2
O
2
, 4 SLM and approximately 15 minutes works fine. Specifically, a.
Use a septum-piercing syringe to inject the desired volume of liquid through the septum. You should see it enter the glass bubbler. b.
Open the gas valve and verify that the flow is at 4 SLM c.
Wait until the droplet fully evaporates. d.
Close the gas valve after that
2) Also use the injection port to introduce the hydrocarbon similar to (1). Some hydrocarbons will need to be heated up in order to vaporize. Use a small heat gun and gently heat the bubbler to achieve this. (In the special case of naphthalene mixed with dichloromethane, it turns into a solid upon injection and introduction to dry air. Heating it up gently will cause the naphthalene to sublime into the chamber).
Turn on the UV Lights and Start the Experiment!
1) Turn OFF the fan (this will reduce wall losses).
2) Turn OFF the flow from the injection port.
3) Switch on all three of the UV lights, and switch off the Vis light.
4) Record starting conditions: a.
Particle mass density in chamber before photolysis. b.
NO, NOy, O
3
before photolysis but after adding NO standard. c.
RH d.
Temperature
5) Record the time you started photolysis: a.
Record the number of seconds on the PTRMS b.
Record the sample # on the SMPS.
***Now what to do when your experiment is done and you need to collect particles and shut everything down***
Turn off the lights and Instruments
1) Switch off UV lights.
2) Stop SMPS data collection, back up data, and turn off the instrument.
3) Stop PTRMS data collection and back up data. To turn off the instrument: a.
Close the TOFDaqRec (your data is saved when you hit stop). b.
Go to the TPS, click on the “shutdown” button and wait for voltages to reach 0.

c.
If you won’t be using the PTRMS for a couple of days, go to the PTR Manager and click
“Operation 
Standby” to turn off all current and water flow. If you will be using the instrument the next day, it’s fine to keep it in operation or on standby – but don’t turn off the PTR Manager! d.
Do NOT plug the inlet of the PTRMS when water flow is ON!!!
4) Record end conditions: a.
Particle mass density in chamber after photolysis. b.
NO, NOy, O
3
after photolysis c.
RH d.
Temperature
5) Take the Ultratorr Tee that is on the stainless steel collection port off. Place a thermal denuder (Sunset
Laboratories) on the stainless steel outlet (make sure there is a ring stand to support the denuder because it is heavy). Connect your filter holder or MOUDI to the denuder and start collection.
6) If using MOUDI pump, also introduce make-up air so the chamber doesn’t collapse. a.
Take the plastic tubing that is in the Nafion humidifier and connect directly to the chamber.
Introduce dry air into the chamber at a flow rate of 25 SLM. b.
Make sure you blind-plug the Nafion humidifier after use.
7) Save the NOy and ozone data off the computer and then turn off both instruments. a.
Select the NOy or O
3
window and click on the “Load Records” button to pull up the data saving window. Select the time you started the experiment and select “save as” and choose file name on the Load Records window. b.
Turn off NOy and O
3
analyzer by switching them off and unplugging all the pumps.
8) At the end of the collection, stop the pump and remove the filter holder or MOUDI.
9) Open the chamber vent valve.
10) Flush with dry air at 60 SLM or higher.

Last updated on April 15, 2020
RESPONSIBLE PERSON
The person responsible for the cleaning is the person who last used the chamber. If several people used the chamber in a given week they should agree between themselves who is going to do the cleaning. The next user may elect to do the cleaning if she/he has special cleaning requirements.
WHEN TO CLEAN
The chamber must be cleaned in the following cases.

At the end of each week (Friday/Saturday) in which the chamber was in operation for any kind of experiment. Exception: if the same type of aerosol will be generated next week and/or the chamber has already been cleaned this week the user may elect to skip the end-of-the week cleaning step.

Whenever the aerosol precursor or environmental conditions are chamber, especially if the precursor is changed from a VOC with a large SOA yield to a VOC with a small SOA yield, or the conditions are changed from dry to humid. If you neglect to clean the chamber in these situations, you will be producing random crap instead of your intended SOA.

Whenever cleaning is part of the experimental design.
CLEANING PROCEDURE:
The full procedure takes two days. The recommended protocol is:

Start flushing on Friday evening.

Introduce the oxidants on Saturday morning.

Initiate the final flush on Saturday evening (unless you are doing the “lazy option” described below)
The details are provided below.
1) Important: turn on the chamber fan and leave it on during the entire procedure to ensure uniform removal of impurities and faster air-wall exchange during cleaning.
2) Flush the chamber with air added through the Nafion humidifier for several hours to purge the content of the previous experiment. If flushing is done at 60 SLM, it will take n

[6 m
3
] / [0.060 m
3
/min] = 100
 n minutes to displace n chamber volumes. This would be roughly equivalent to 100
 exp(-n) % of the previously used chemicals remaining in the chamber after the flush. The following table illustrates the effect of flushing and suggests that at least 5 hours are needed to achieve 99% removal of the chamber content. Therefore, flushing the chamber overnight (e.g., Friday night) is recommended. n
7
8
9
5
6
3 time needed (hr) Impurities remaining (%)
5.0 4.98
4 6.7 1.83
8.3
10.0
0.67
0.25
11.7
13.3
15.0
0.09
0.03
0.01
3) The humidity should be fairly high at the end of the flushing, and condensation may appear on the walls.
This is OK, and is in fact desirable as high RH will help push the impurities off the walls.
4) Stop flushing the chamber.
5) Close the manual shut-off valve to isolate the chamber.
6) Introduce 10-100 ppm of ozone in the chamber (the exact amount is irrelevant). Let the chamber sit for
1 hour.

7) Introduce 2 ppm H
2
O
2
in the chamber (the exact amount is irrelevant).
8) Turn on UV lights for 6-12 hours using the automatic timer and let the chamber sit.
9) Turn the lights off (if they are not off already), open the manual shut off valve, and flush the chamber with dry air overnight. Lazy Option (not recommended): start flushing simultaneously with turning the lights on, i.e., combine steps 8 and 9.