A rotary evaporator is one of the most commonly used chemical lab devices. Its role is to remove solvents from various samples in a gentle yet effective manner. There are many reasons why labs use such devices in their daily work. This article takes a closer look into the main purposes of using this gentle distillation method.
The first use of a rotary evaporator is to concentrate non-volatile components in a solution. For instance, if you want to obtain a plant extract, you can use a rotary evaporator to remove the water from the mixture. This is an effective method to extract volatile aromas and flavor molecules without needing to make use of high temperatures. This is why such devices are widely used in molecular cooking for the preparation of extracts and distillates. Their main role is to enable the extraction of specific flavors from blends of herbs, alcohols and fruit without using heat to separate the main compounds in the mixture.
The best way to gain a better understanding of the rotary evaporation process is to change your perspective. Distillation is nothing else than the separation of different substances in a mixture. this procedures allows us to separate acids, colors and sugars from alcohols, water, aromas and small flavor molecules. What makes this method better than standard distillation is that it doesn’t alter these molecules and food compounds in any way. Heat, on the contrary, alters their structure, thus leading to a totally different outcome.
A rotary evaporator allows for a precise and gentle distillation conventional machines cannot provide. The main reason why rotary evaporators are better than traditional devices is that it removes the solvent under vacuum. Vacuum lowers the boiling point, therefore eliminating the need for high temperature for the distillation process to occur. This reason should be good enough to determine labs and molecular cooking facilities to use this distillation method rather than the traditional one.
The second reason why rotovaps are better than traditional distillation machines is that the surface area of the product is much higher, thanks to the rotation of the evaporation flask. This rotation speeds up distillation a great deal, making the whole process way more efficient than its traditional alternative. Also, the forced convection helps to keep the mixture heated and evenly mixed. The result is a stable and even evaporation process which is more precise than other methods.
Last but not least, the technician has visual access to the process, being, therefore, able to monitor and adjust it as needed. These laboratory condensers are made of glass, so everybody can see what happens inside them. They are also sealed, thus allowing for the recovery of almost 100% of the solvent. This makes the process extremely economical, as well.
All these being said, it’s easy to understand why more and more labs prefer investing in rotary evaporators rather than sticking to their old distillation methods. The effectiveness, efficiency, and accuracy of this method are good enough reasons for many labs across the world to use it.