subject: How Solvent Evaporator Products Are Used In The Laboratory [print this page] In product manufacture it is often desirable to create a concentration of extracted materials from the raw materials. While the evaporation process brings many familiar products to the table like table salt, sugar and maple syrup it also has many applications in research, chemical, pharmaceutical and clinical laboratories. In a lab environment there are a variety of instruments called solvent evaporators which are designed to do this job.
This is basically a piece of scientific equipment used in laboratories which facilitates the concentration of extracted material from other liquids or solids. Another name for the process is sample enrichment.
Today's modern rotary evaporators are not that far removed from the design proposed in a one-page scientific paper published in 1950 by Lyman C. Craig, Gregory and Hausmann. Their "Versatile Laboratory Concentration Device" was in effect a simple Rotary Evaporator. The design was picked up by Swiss company Bchi in 1957 and has been sold commercially ever since.
Nitrogen blowdown evaporators, also known as gas blowdown concentrators use gas jets to force vaporised molecules to immediately leave the surface of the solution before they have the chance to revert to liquid form. This speeds up the evaporation process and is especially useful when sample surface area is small as it is when working with microplates or test tubes.
Vaccum evaporators use a similar principle as Nitrogen Blowdown versions in that they remove vapour from the surface of the sample but they do so in a different way. Instead of gas jets they use vacuum pumps. Rotary evaporators work by rotating a flask which contains the sample dissolved in a solution which is most often water through a heated bath and collecting the evaporating gases. They usually offer temperature and vacuum control.
While rotary evaporators are standard lab equipment they generally run only one or limited samples at one time.
When more samples are needed a centrifugal evaporator is used which efficiently collects the evaporated solvent from many samples at a time.Using a vacuum pump which connects to the centrifuge unit, the system lowers the pressure in the centrifuge unit at the same time lower the temperature at which the solutions will boil. This allows solvent to be collected without as much stress to the original sample solution.
The pressure created in some modern centrifugal evaporators on the samples contained in the microplate wells causes them to boil from the top down. This is a great advantage because it eliminates 'bumping', which is the loss of sample solution due to overheating.
Whichever evaporator is used either the concentrated residue left behind after the solution has been vaporised or the collected gases could be the target material.
Solvent evaporators are already widely used but they are also constantly evolving with new designs attempting to further lower temperatures and time required as well as increase volume for high-throughput environments. Anyone looking to purchase a solvent evaporator should consider volume required and the sensitivity of the base materials they are working with to decide on which of the solvent evaporators would best fill their needs.
