Teledyne CombiFlash Rf User Manual page 58

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CombiFlash® Rf User Manual
settings are discussed in Section 7, R
select this option for these initial installation steps.
Default Run Units – Run units are displayed along the
X-axis of the chromatogram. Select Time (in minutes) or
Column Volumes. A column volume unit is the time it takes to
pump enough solvent to exchange the volume held by the
column. The duration in minutes will vary according to the
column media and size, and the flow rate.
Gradient Method – Select the standard gradient type
(Figure 2-9).
• Linear – The system gradually mixes solvents A and B
from the last programmed %B until it reaches the next
programmed %B. This method connects the inflection
points that define the gradient with a straight line.
• Step – The system holds each %B value until it reaches
the next programmed %B. Because the system holds the
%B values, the changes at each new value are nearly
instantaneous, producing a stepped appearance on the
plot area.
• Isocratic – The system holds the initial solvent mix for
the entire run.
Figure 2-9 Gradient types
Enable Run Length Extension – When enabled, this option
automatically extends the run if a peak is eluting at the end of
the maximum %B gradient. This ensures that a late-eluting
peak fully comes off the column and is collected.
An automatic run extension is a five-minute isocratic hold
added to the end of the run's maximum %B gradient profile.
During the extension, the system continues to pump the
maximum %B solvent mixture. Should the system still detect
2-22
Linear
I
EMOTE NTERFACES
Step
. Do not
Isocratic