This slide consists of the definition, parts, and functions, and the principle of the rotary evaporator. Besides this, I also added why we using a rotary evaporator and the comparison between a rotary evaporator and a lyophilizer.

1. Rotary Evaporator
AB/RTE/02
By Shubashini A/P Balakrishnan (TH1370)

2. Definition of Rotary Evaporator
• Rotary evaporator also called as “rotavap”.
• Comprised of a vacuum pump and coding circulator which involves
the mechanical rotation of the evaporation flask under low
pressure.
• The evaporation process occurs at an elevated temperature and
reduced pressure
• This helps encourage the rapid elimination of excess solvent from
less volatile samples(TFA , Acetonitrile)

3. Parts and Function of Rotary Evaporator

4. Parts and Function of Rotary Evaporator
PARTS FUNCTION
Rotary Motor rotates the evaporating flask; increase the surface area of the solution
Vacuum source the system responsible for creating a vacuum within the airtight set-up, thereby
reducing the pressure within the system.
Heating bath used to heat the solution in the evaporating flask ; ↑ evaporating rate
Condenser to condensate the evaporated sample as well as enhance convenient sample
collection.
Receiving flask to receive the distilled sample.

5. Principle of Rotary Evaporator
The evaporation vessel is constantly rotating so as to
increase the evaporation surface area per unit time
The centrifugal force produced keeps the liquid
stuck to the inside of the vessel providing a
large surface area
↓ pressure, Bp of
Liquid ↓
condenses the gas →
liquid by chilling &
cooling the vapor.
considered when
separating low boiling
solvents

6. Why Rotary Evaporator?
• The removal of solvent by a rotary evaporator is superior to evaporation under
atmospheric pressure for many reasons.
• The process much quicker
• Uses lower temperatures and less energy than boiling with a heat source.

7. Place the extract in
round- bottom flask
Join the bump trap to the
flask
Red bolt to fix the flask
Check level and
temperature of the water
Optimize the temperature
and rotation speed of the
flask
For example, Bp of the
solvent is 40ºC, bath temp
of 60ºC and coolant
should be 20ºC provide an
optimal setup
Switch on chiller and
circulate cooling water
and vacuum
Evaporated solvent
condenses and drips in to
the collector
Concentration completed Collect the extracted
The Process of Rotary Evaporator

8. Rotary Evaporator vs Lyophilizer
Rotary Evaporator Lyophilizer
Evaporation and condensation takes place
• Liquid → Gas (in evaporator flask)
• Gas → Liquid (in condenser coil)
Sublimation takes place
• Solid → Gas (without passing through liquid phase)
Less time required (5 to 15 minutes or more) More time required (72hours)
Limited life span for end product The end product can be stored for many years
Used to separating chemical solvent and used in creating
several high-quality pharmaceutical products.
Used to improve stability and storage of labile drugs and
applied to the production of injectable dosage forms of
drugs.

9. Precautions of handling and operating rotary
evaporator
• Check your flasks before every use and handle them carefully. (Damaged glass can
break easily under heat and pressure)
• Keep the heating medium below its boiling temperature.
• Don’t overload the sample flask.
• Monitor the evaporation flask rotation to prevent uneven heat or drying of sample on
one side.
• Allow heat bath and evaporation flask to cool before removal
• Always wear appropriate personal protective equipment in case of breakage or
splashing.

10. THANK YOU!