Standard Operating Procedure
LABORATORY ROTARY EVAPORATORS
Investigator: General Safety
1.0
Location: OES
Page 1 of 7
Revision: 00
PURPOSE:
Working with hazardous chemicals at high or low pressures requires planning and special
precautions. Procedures should be implemented to protect against explosion or implosion
through appropriate equipment selection and the use of safety shields. Care should be taken to
select glass apparatus that can safely withstand designated pressure extremes. This SOP
provides general safety procedures for the use of rotary evaporators in a laboratory setting.
2.0
SCOPE:
This procedure applies to all Louisiana State University Personnel that work in a laboratory and
have the potential to use a rotary evaporator. It is the intent of this guideline to provide
information on the proper use of a rotary evaporator in a laboratory at LSU and afford employee
protection while working in a laboratory.
3.0
RESPONSIBILITIES:
Only trained and qualified personnel shall be allowed to work in a laboratory at LSU. Each
laboratory worker is directly responsible for safe operation of laboratory equipment. Supervisors
are responsible for ensuring that personnel are trained to work safely in a laboratory. All
laboratory personnel are responsible for reading and understanding this procedure.
4.0
5.0
DEFINITIONS:
4.1
High vacuum - Typically 10-3 millibars or better produced using a vacuum pump.
4.2
Low vacuum – Typically around 30 millibars produced by a water pump
REFERENCES:
Not Applicable
6.0
MATERIALS and/or EQUIPMENT:
Personal Protective Equipment
Safety Shielding
Rotary Evaporator System
7.0
PROCEDURES:
Vacuum work can result in an implosion and the possible hazards of flying glass, spattering
chemicals, and fire. Implosion and flying glass can lead to cuts and lacerations. Any piece of
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Standard Operating Procedure
LABORATORY ROTARY EVAPORATORS
Investigator: General Safety
Location: OES
Page 2 of 7
Revision: 00
glassware under vacuum has the potential to do harm following implosion. The energy imparted
to flying fragments is directly proportional to the volume of the glass vessel evacuated It is a
common misconception that so called "high vacuum" (typically 10-3 mbars or better) systems
present a significantly greater hazard than everyday vacuums produced by e.g. a water pump
(around 30 millibars). These may differ by four orders of magnitude but the forces to which the
glassware is subjected is essentially the same.
7.1
General Precautions For Working With Rotary Evaporator Systems
7.1.1
Personal protective equipment, such as safety glasses or chemical goggles, face
shields should be used to protect against the hazards of vacuum procedures.
7.1.2
Always place a safety screen between the operator and glassware under
increased or reduced pressure.
7.1.3
Only handle these types of equipment in the presence of others.
7.1.4
Use heavy-wall rubber tubing only. Thin-wall rubber tubing and plastic tubing are
not suitable because they collapse leaving a partially evacuated closed system.
7.1.5
Although glass vessels are frequently used in vacuum systems, they can explode
or implode violently, either spontaneously from the strain or from an accidental
blow. Therefore, pressure and vacuum operations in glass vessels should be
conducted behind adequate shielding. Glass vessels should be designed for the
operation intended, and should be visually checked for star cracks, scratches, or
etching marks before each use.
7.1.6
Flasks with volumes of 1 liter or larger and the cooling condenser must be
enclosed in tape or plastic mesh to restrain fragments in case of implosion.
7.1.7
Glass dewars should be fully wound in tape or preferably enclosed in a metal
container.
7.1.8
The rotation speed and application of vacuum should be done gradually when
using a rotary evaporator.
7.1.9
Do not hold onto the sample whilst it is revolving: failure of the flask could result
in serious lacerations to the hands.
7.1.10 Slowly admit air back into the apparatus after evaporation of the solvent is
complete.
7.1.11 Clean the apparatus after use. Do not mix halogenated and non-halogenated
solvents in the receiver.
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Standard Operating Procedure
LABORATORY ROTARY EVAPORATORS
Investigator: General Safety
7.2
Location: OES
Page 3 of 7
Revision: 00
Low Vacuum Rotary Evaporators
A low vacuum (typically around 30 millibars) rotary evaporator system uses a water
aspirator reduce the pressure so that solvents can be separated. The use of cold traps
is dependent on the solvent.
7.2.1
Hook up tubing as between the vacuum source and the rotary evaporator.
7.2.2
Make sure the round bottom (RB) flask is twice the volume as your sample
volume.
7.2.3
Keep the inside of all tubing as large as possible so the vacuum is strong.
Suggested vacuum tubing size is approximately 3/16” wall thickness x 5/16” ID.
7.2.4
Fill water bath with deionized water, set temperature and turn on.
7.2.5
Put solvent “catch pot” in place.
7.2.6
Fill ice bucket and place under catch pot to remove as many solvents as possible
from condenser.
7.2.7
If required, hook up the solvent trap and fill it with ice.
7.2.8
Make sure tubing from the condenser carrying the warmed water is in the drain.
7.2.9
Fill cooling coils inside condenser and leave cooling water flowing if you’re ready
to evaporate a sample (Use chiller if you have one).
7.2.10 Make sure vacuum valve at top of the condenser is “open” so you’re not pulling a
vacuum yet when you put on your sample flask.
7.2.11 Attach the RB sample flask to the condenser and fasten into place with a clamp.
7.2.12 Start rotation of flask slowly and gradually increase speed.
7.2.13 Slowly close the vacuum valve at the top of the condenser – watch for bubbles in
your sample! Adjust vacuum as needed.
7.2.14 Once the sample has stabilized, lower the flask into the water bath.
7.2.15 Continue the process as long as necessary.
7.2.16 If you need to break the vacuum to the pump to discard solvent from the trap or
add ice to the solvent trap, open the valve and leave the vacuum pump running.
Discard solvent/add ice, shut valve and continue with rotary evaporation of
sample.
7.2.17 When completely done with evaporating all samples, open valve to break
vacuum and continue to run water at least 5 minutes.
7.2.18 Solvents should be poured into proper bottles and labeled for waste collection.
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Standard Operating Procedure
LABORATORY ROTARY EVAPORATORS
Investigator: General Safety
7.3
Location: OES
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Revision: 00
High Vacuum Rotary Evaporation Set-Up
A high vacuum (typically 10-3 millibars or better) rotary evaporator system include the
use of a vacuum pump or a house vacuum system to reduce the pressure so that high
boiling solvents and be separated. The system also requires the use of cold traps to
prevent solvent contamination of the vacuum source.
7.3.1
Hook up tubing as between the vacuum source and the rotary evaporator. Be
sure to note the in and out labels on the solvent trap.
7.3.2
Make sure the round bottom (RB) flask is twice the volume as your sample
volume.
7.3.3
Elevate the vacuum pump above the traps to aid in keeping the solvents out of
the pump.
7.3.4
Be sure to add an open/close valve between the last trap and the vacuum pump
to aid in solvent removal from traps
7.3.5
Keep the inside of all tubing as large as possible so the vacuum is strong.
Suggested vacuum tubing size is approximately 3/16” wall thickness x 5/16” ID.
7.3.6
Using dry ice is the recommended method of keeping the atmosphere cold to
condense the solvent. If you choose to use an ice, rock salt (used for making ice
cream) and water slurry please test the system first to see how many traps you
must use to keep solvent out of the vacuum pumps as that can damage the
pumps over time. A handy way to check this would be a check of the last sidearm flask before the pump and see if any solvent has precipitated. Also place a
piece of clear Tygon tubing on the out vent of the vacuum pump and check for
solvent droplets that may have formed. If you are using glass as part of the
connection in a side-arm flask remember to use glycerin to wet the glass. Wear
gloves to protect your hands and hold the glass next to the point you are applying
pressure when putting the vacuum tubing on.
7.3.7
7.4
The temperature of dry ice is -78.5 ºC.
High Vacuum Rotary Evaporation Procedure:
7.4.1
Fill water bath with deionized water, set temperature and turn on.
7.4.2
Put solvent “catch pot” in place.
7.4.3
Fill ice bucket and place under catch pot to remove as many solvents as possible
from condenser.
7.4.4
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Hook up dry ice trap.
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Standard Operating Procedure
LABORATORY ROTARY EVAPORATORS
Investigator: General Safety
Location: OES
Page 5 of 7
Revision: 00
7.4.5
Fill trap with dry ice or flaked ice and rock salt (if known to work).
7.4.6
Add a second and even a third side-arm flask “trap” between dry ice trap and
vacuum pump if you are seeing condensation in the clear tubing coming out of
the vacuum pump.
7.4.7
Place secondary ± tertiary “traps” into an ice bucket to catch any additional
solvent fumes carried past the first trap.
7.4.8
Make sure tubing from the condenser carrying the warmed water is in the drain.
7.4.9
Fill cooling coils inside condenser and leave cooling water flowing if you’re ready
to evaporate a sample. (Use chiller if you have one.)
7.4.10 Make sure vacuum valve at top of the condenser is “open” so you’re not pulling a
vacuum yet when you put on your sample flask.
7.4.11 Attach the RB sample flask to the condenser and fasten into place with a clamp.
7.4.12 Start rotation of flask slowly and gradually increase speed.
7.4.13 Slowly close the vacuum valve at the top of the condenser – watch for bubbles in
your sample! Adjust vacuum as needed.
7.4.14 Once the sample has stabilized, lower the flask into the water bath.
7.4.15 Continue the process as long as necessary.
7.4.16 If you need to break the vacuum to the pump to discard solvent from the trap or
add ice to the dry ice trap, open the valve and leave the vacuum pump running.
Discard solvent/add ice, shut valve and continue with rotary evaporation of
sample.
7.4.17 When completely done with evaporating all samples, open valve to break
vacuum from pump; disconnect tubing from inlet of vacuum pump and allow
pump to run at least 5 minutes to dry out any droplets of moisture that might be
inside it.
7.4.18 Shut off vacuum pump after 5 minutes. It is possible to plug the vacuum pump
into a timer so that the pump is turned if you forget to watch the time.
7.4.19 Solvents should be poured into proper bottles and labeled for waste collection.
7.5
Use of Flaked Ice
Follow the SOP for general rotary evaporation setup and procedure. This test procedure
is to verify whether you can use flaked ice (“crushed ice”) rather than dry ice in your
rotary evaporation setup with your particular solvent(s). It will also indicate how many ice
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Standard Operating Procedure
LABORATORY ROTARY EVAPORATORS
Investigator: General Safety
Location: OES
Page 6 of 7
Revision: 00
traps you need with your particular solvent(s). This MUST be done with each different
solvent or a change in temperature with the same solvent.
7.5.1
Ice the catch pot. This MUST be done. It has been found that approximately 1/3
of the solvent goes past one trap on to the pump/drain when the catch pot is
NOT iced.
7.5.2
Place ice and rock salt inside the “dry ice” trap.
7.5.3
Run your rotary evaporator and watch for solvent collection in the catch pot, and
dry ice trap. Also watch for any moisture droplets forming at the outlet of the
vacuum pump. 4. If you have ANY moisture at the outlet of the vacuum pump,
you MUST add another ice trap.
7.5.4
While adding the additional trap, be sure and disconnect the inlet tubing to the
vacuum pump and let it run to dry it out.
7.5.5
Add a side-arm flask “trap” between the dry ice trap and vacuum pump.
7.5.6
Place “trap” into an ice container to catch any additional solvent fumes carried
past the first trap.
7.5.7
If moisture is gone from outlet of pump, connect everything and you’re ready to
run your rotary evaporator again.
7.5.8
Watch for moisture droplets forming again at the outlet of the vacuum pump.
7.5.9
If you still have moisture (solvent) droplets forming at the outlet of the vacuum
pump after icing the catch pot, and having two ice traps between the condenser
and the vacuum pump, then you have no choice but you MUST use dry ice rather
than flaked ice to make it cold enough to chill your particular solvent fumes.
8.0
CONTINGENCIES:
8.1
In case of a fire, explosion, or gas leak evacuate individuals from the area and call the
emergency response (911). Notify supervision and adjacent personnel as quickly as
possible. Observe appropriate procedures for personal injury or fire as provided in OES
Web site.
8.2
In case of a chemical spill, alert others in the immediate vicinity and notify your
supervisor. Determine the severity of the spill and proceed as appreciate. Small spills
may be cleaned up by laboratory personnel. For large spills, notify OES (578-5640) and
Campus Police (911 or 578-3231). If possible to do so safely (without risk of over-
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Standard Operating Procedure
LABORATORY ROTARY EVAPORATORS
Investigator: General Safety
Location: OES
Page 7 of 7
Revision: 00
exposure), take action to stop the release. Ensure that extraneous personnel remain at
a safe distance until the spill is completely cleaned-up
9.0
REVIEWS AND REVISIONS:
This procedure shall be reviewed for compliance and effectiveness and revised as necessary on
an annual basis.
10.0
ATTACHMENTS and REFERENCE FORMS:
Not Applicable
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