Rotary removal

Rotary removal of relatively large solvent quantities, e.g. in pharmaceutical research

In the development of new medicinal substances, the active ingredients are either extracted from natural sources or produced by synthesis. In both cases it is often necessary to remove large quantities of solvents, such as for re-dissolution or for building up substance libraries. The complex molecules in these solvents are thermally sensitive, which makes drying under vacuum the preferred method.

Commonly used solvents include:

  • dichloromethane
  • ethyl acetate
  • alcohols
  • acetonitrile
  • tetrahydrofurane
  • toluene
  • dimethylformamide
  • dimethylsulphoxide

In addition to conventional rotary evaporators, more and more RVC-systems are used for round-bottom flasks as well. The evaporation time for media with relatively high boiling points, including water, is approximately 12 hours with four 500-ml round-bottom flasks. Automatic switch-off (using the product temperature sensor) and operation under program control allow the process to run unattended, or even overnight if necessary.

Vapour pressure curves of commonly used organic solvents
Vacuum concentrator RVC 2-33 CDplus with IR heating and rotor for four 500-ml round-bottom flasks with product temperature sensor