How does a rotary evaporator remove solvent?
A rotary evaporator is mainly used to continuously distill a large amount of volatile solvents under reduced pressure, such as extraction by distillate and a receiving liquid for chromatographic separation.The basic principle of a rotary evaporator is to evaporate sample materials with evaporation flask’s continuous rotation. The process can be descriped as follows:
- Turn on the chiller. Press the power button and the cooling button to lower the desired temperature and then cycle.
- Turn on the pump to circulate water.
- Install the distillation flask and secure it with a clamp. Turn on the vacuum pump and start rotating after a certain vacuum is gained.
- Adjust the height and rotation speed of the distillation flask and set the appropriate water bath temperature.
- Stop the rotation after steaming, then pass the atmosphere, stop the pump, and finally remove the distillation flask.
- Stop the chiller as well as the water bath, turn off the water circulating pump, pour out the solvent in the receiving flask, wash the buffer ball, and remove the flask.
The tips on removing solvent by a rotary evaporator
- Users need to remove the gas within equipment to create a vacuum environment, then rotate to prevent the distillation flask from slipping. When you want to stop it, stop rotating firstly. Then hold the flask when you pass the atmosphere into equipment. Stop the vacuum pump until the vacuum gets reduced to 0.04MPa to prevent the distillation bottle from falling off and sucking back.
- Each interface, sealing surface, sealing ring and joint needsto be coated with a layer of vacuum grease before installation.
- The heating tank must be filled with water before it is energized. It is not allowed to dry without water.
How does a rotary evaporator work?
a. Pour the mixture of solvent and required compound in a round bottom flask, which should be fiiled less than half full of the solution.
b. Fill the rotovap cold traps with dry ice.
c. Attach a glass “bump trap” to prevent any solution from entering the main part of the rotovap. Secure with a clip.
d. Connect the flask and bump trap to the adaptation part with a clip.
e. Lower the flask into the water bath, preventing the flask from disconnection.
The working process of rotary evaporator is a consecutive process under a reduced environment. There are several steps for the operation:
a. Under reduced pressure, the evaporation flask was continuously rotated while the solvent was being distilled. The evaporation flask is a pear-shaped or round-bottomed flask with a standard ground mouth connection. It is connected with the pressure reduction pump through a serpentine condenser.
b. After substances get evaporated by heating, the gas-phase substances will go into condensing part to get condensed. In this step, gas substances are transferred through the glass tubes.
c. After gas-phase substances got condensed into liquid-phase, the liquid-phase substances will be transferred into receiving flask, which is the final destination of extracted substances. And then users will take the receiving flask out of rotary evaporator equipment.
During the whole working process, there is always a vacuum pump providing a vacuum environment for the rotary evaporator, which guarantees the whole system work in a reduced environment and the automatic feeding system formed by the pressure difference between atmosphere pressure and vacuum pressure.
Can a rotary evaporator remove water?
Rotary evaporator is widely used in removing water from materials, which is to concentrate substances. Removing water by rotary evaporator is commonly used in kitchen, for example, concentrate fruit juice, which is to remove water from fruit juice. Besides, there are other examples of removing water from substances.