Advantages and Disadvantages of using a Rotary Evaporator?

A Rotary evaporator is a laboratory equipment, applied in the chemical sector, capable of separating or rescuing substances at very low pressures, to extract from them the various elements that compose it, through distillation processes, and to be able to separate the components from each other.

This equipment, is generally used in the pharmaceutical industry and in chemical laboratories, for the effective and smooth removal of solvents from samples by evaporation. They are also used in molecular cooking for the preparation of distillates and extracts. Its function, which is basic and common in the chemistry laboratory, allows to dissolve volatile organic elements, coming from a reaction mixture or a process such as liquid-liquid extraction. Although this operation, in principle, could be done by simple distillation, the fastest and most convenient method, is the use of a Rotaevaporator for distillation at reduced pressure.

Advantages and Disadvantages of the Rotary Evaporator

Modern rotary evaporator technologies are particularly useful when you have many samples to do in parallel, as in the medium to high yield synthesis, which expands in the chemical industry. Evaporation can be performed using standard organic distillation glass material, i.e. without sample rotation.

The key advantages of using a rotary evaporator are:

  • The centrifugal force and the friction force between the wall of the rotating flask and the liquid sample result in the formation of a thin film of hot solvent, which extends over a large surface.
  • The forces created by rotation suppress the blows. The combination of these characteristics and the convenience of modern rotary evaporators allows for a quick and smooth evaporation of the solvents from most samples, even by relatively inexperienced users. The solvent remaining after rotary evaporation can be removed by exposing the sample to an even deeper vacuum in a more hermetically sealed vacuum system at room temperature or above.

A key disadvantage of Rotary evaporators, in addition to their unique sample nature, is the potential of some types of butt samples, e.g. ethanol and water, which may result in the loss of some of the material intended to be retained. Shocks can often be prevented by introducing homogeneous phases into evaporation, carefully regulating the vacuum force (or bath temperature), to provide a uniform rate of evaporation, or, in rare cases, by using added agents, such as boiling chips (to make the nucleation stage of evaporation more uniform).

Finally, Rotary evaporators can be equipped with other special traps and capacitor assemblies that best suit particularly difficult sample types, including those with a tendency to foam or shock.

Recommendations for Use

Potential risks include implosions resulting from the use of faulty glass items such as star-shaped cracks. Explosions can also occur by concentrating unstable impurities during evaporation. Accordingly, it is recommended that users of equipment take precautions to avoid contact with rotating parts, especially entanglement of loose clothing, hair or necklaces. In these circumstances, the winding action of the rotating parts can attract users to the apparatus, which causes the breakdown of glassware, burns and chemical exposure. In addition, additional caution should be applied to operations with reactive materials in air, especially when under vacuum. A leak can draw air into the device and a violent reaction can occur.

Kalstein Rotary Evaporators

At Kalstein, we are manufacturers of the most comprehensive technology in trained laboratory equipment, to meet all the demands of our customers. In this case, we offer you the Rotary Evaporators belonging to the YR series, with general, attractive features, such as; patented technology of double Teflon Sealing (PTFE) and FV rubber ensures the level of negative pressure. Automatic switching valve for continuous collection, without affecting the vacuum degree and without stopping distillation. Teflon discharge valve, corrosion resistant and pollution free. Water bath jacket, which protects the operator from burns by hot liquid.

In addition, we offer extensive advice, with the best experts, so that your purchase is ideal and at excellent prices. To learn more about our catalog, visit HERE

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