Chapter 4: Using Your RapidVap
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Original instructions
Heat Setting Guidelines
The evaporation rate achieved by the RapidVap is dependent upon a variety of
factors. These include the nature of the solvent, the temperature, the pressure in
the vacuum system or the flow of the nitrogen gas in the RapidVap N
2
, the volume
of sample, shape of tubes and vortex speed. Because of the multiplicity of factors
it is impossible to give “typical” performance data.
By design, the RapidVap Vacuum model can be run at lower temperature settings
than the RapidVap N
2
model. This is because the decrease in pressure will cause
the sample to evaporate at a lower temperature. As a general guideline, to speed
the evaporation process, the RapidVap temperature should be set as high as
possible as long as the temperature will not damage the sample or cause the sample
to bump.
In the RapidVap Vacuum models, generally the evaporation rate will be optimized
with the block temperature set and preheated 20 to 40°C above the boiling point of
the solvent at the operating pressure.
For example, methanol (which boils at 65°C at atmospheric pressure) boils at 5°C
at pressure of 53 mBar. Under these vacuum conditions, the block temperature
should be set between 25 to 45°C. The nomogram and equation to follow will help
in this determination.
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