About Solvent Level Detection - Teledyne CombiFlash Rf User Manual

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CombiFlash® Rf User Manual
T = Cartridge Volume / (Rf * Flow Rate)
Where T is the time in minutes to wait after the system
reaches the %B solvent used to run the TLC plate; Rf is the
retention factor measured in step 1; Cartridge Volume is
the volume in mL from step 2; and Flow Rate is the current
flow rate in mL/min.
5. Observe the current %B concentration in the status bar.
Once the system reaches the %B percentage used for the
TLC, wait at least the time established as T. After this time
has elapsed it is likely that the desired compound has come
off the cartridge and you can safely click the Cartridge
Bypass button.
For example, a TLC plate run at 30%B revealed that the last
desired compound had an Rf factor of 0.35. An empty 25-gram
size solid load cartridge was filled with sample adsorbed onto
10 grams of silica, and then placed on the system. The
programmed flow rate was 60 mL/min. During the run, the
flow rate dropped to 30 mL/min. The equation is then:
T = 45 mL / (0.35 * 30 mL/min) = 4.3 minutes
In this example, the Cartridge Bypass feature was used 4.3
minutes after the solvent gradient reached 30% B.
The calculation is conservative, but allows you to minimize the
time needed to keep the solid load cartridge in the fluid path.

5.4.3 About Solvent Level Detection

When enabled in the T
CombiFlash Rf
the solvent volume usage by measuring the solvent level in the
container and the monitoring the usage rate. The system
continues to refine this estimate of available solvent during
operation.
At the beginning of a run, the system calculates the amount of
solvent required to complete the run. The system will alert you
if it detects that there is not enough solvent at the start of the
run. Likewise, the system will alert you during the run if the
estimated usage rate or the measured level indicates that
there is insufficient solvent. Note that pauses and automatic
run extensions during a run will increase the required solvent
volume.
5-14
>Configuration window,
OOLS
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, Rf Lumen and Rf 4x systems will estimate