A rotary evaporator (rotavap) is a laboratory equipment used in the process of separating solvents by distillation. Distillation involves the separation of a particular mixture into its components and relies on the varying evaporation points of the different elements that constitute the mixture. The separation method employs evaporation and condensation.
Conventional distillation involves heating solvents to high temperatures. Conversely, rotavap distillation is typically used to separate solvent at lower temperatures. It is used with liquid solvents that can be isolated without too much heating of the compounds(solvent and solutes) that are sensitive and complex.
You need a rotavap for various separation processes and to perform multiple experiments, especially for analysis in the lab.
The following are some things you should have in mind when buying a rotavap :
The Samples to be Separated
The samples that you are to use in the evaporator are a vital thing to consider because it influences how the evaporator is set up. If you are to use a corrosive sample, such as an acid, the evaporator parts need to be coated well to prevent corrosion. The pump specifically needs coating.
The solvents may also result in damage to the rubber and plastic parts, so they need protection. So, it would be best if you considered the different samples that condense at varying temperatures.
Several options are available when it comes to condensing and collecting samples. Some evaporators have cold fingers and coils which need to have cold water or ice connection. Although the set up works well, there is the downside of wastage due to the constant need to change the water.
To avoid the wastage, evaporators that come with circulating chillers attached are better. Condensation happens well, and there is no water wastage.
The safety of the operator should be a big concern since the equipment heats acids, aqueous samples, and solvents. By using some accessories and parts, the safety of the operator can be ensured. Coated glassware is recommended to prevent shattering since the glass is subjected to extremely high pressure because of the heating and the vacuum pump.
Furthermore, protective hoods and shields having ventilation can guarantee the operator’s safety. Also, some evaporators have sophisticated safety features, such as automatic shut-offs and motorized lifts.
On top of the above things to consider, you must bear in mind air impermeability is a critical determinant of the performance of a rotavap. It influences the functioning as well as the durability of the equipment. Some things that determine air permeability in rotavap are the materials used to make it, the standards of the manufacturer, and design.