Teledyne ACCQPrep HP125 Installation And Operation Manual page 91

Initial Waste & Time Windows – The initial waste diverts
a user-determined volume to the waste port until the eluant
is about to be collected. At the start of a run, the internal
solvent lines hold some solvent from the previous run. This
volume can be diverted to waste, along with the anticipated
volume of fluid that will pass through the column before a
compound of interest will elute.
Time Windows can limit the fraction collection to specific time
durations of the run. To use time windows enter a start time and
an end time. All times are relative to start of the run, just fol-
lowing the sample injection. Then choose a peak collection mode.
If you select Peaks, the module will collect fluid only when the
time window is active and a peak is present. If you select All, the
module will collect all fluid during the time window regardless of
the peak state. Define up to three time windows.
Peak Collection – There are three peak collection options:
All, Peaks, or None. The All option will collect peak and
non-peak fluid in tubes. The Peaks option will collect only
peak fluid in tubes and divert all other fluids to the waste
port. The None option will divert all fluids, peak and
non-peak, to the waste port. The None option is useful for
developing custom methods that perform a column wash,
system cleaning, or similar function where solvents and
elute do not need to be collected.
When using the All or Peaks options, you can specify the
maximum Peak and Non-peak volumes to be collected in
the tubes. Be sure to enter volumes less than the maximum
tube capacity. Different peak and non-peak tube volumes
can be used to conserve tubes when using the All peak col-
lection mode by collecting large volumes of non-peak fluid
while creating more, smaller fraction volumes of fluids of
interest.
The fraction collector will advance to the next tube when-
ever a peak is detected. Also note that the system will
advance to the next tube if a new peak is detected before
completing the last one (sometimes called a double
advance). Tubes may also advance, when using multiple
detectors, depending on impurities or sensitivity to a given
compound by each detector. Keep in mind that the slope
and threshold detection methods use algorithms which opti-
mize the peak detection. For example, peak detection
includes a hysteresis to reduce the likelihood of multiple
tube advances that may occur if there is noise at the begin-
ning or tail end of a peak.
ACCQPrep HP125
Section 5 PeakTrak
5-27