Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual page 61

Fraction Collection - Delay and Detector Offset Options
Set the delay time or delay volume between the first detector in the system and the fraction
collector.
• Delay Time: This is a constant value which should only be applied with a constant pump
flow rate of your method. Note that changing the flow rate requires an according adaption
of the delay time to allow for proper fraction collection.
Delay Volume: This is the fluidic volume travelled by a peak after triggering the set start
threshold conditions between a detector and the separation point of the diverter valve.
Using the delay volume offers more flexibility, as Chromeleon automatically calculates the
delay time from the pump flow rate and the defined delay volume.
Both the delay volume and the delay time should be determined experimentally with a
suitable method. As a first approximation, the delay volume can be determined as a result
of the volume calculation of all tubing between the detector cell and the diverter valve.
Note that the volume of the drop former itself does not contribute to the delay volume but
to the carry over volume. It is recommended to perform a suitable test with some collected
fractions to assure proper functionality and fraction collection quality.
• If more than one detector is used, enter the delay time offset between the first detector after
the separation column and the subsequent detector or detectors under Detector Delay
Offsets.
Fig. 23: Fraction Collection Wizard: Delay and Detector Offset Options page
After completion of the wizard, Chromeleon creates a program file (method). Use this
program as a basis and add the required AFC-3000 commands and properties, for example,
by copying them from the example program provided in the appendix.
Operating Instructions
UltiMate 3000 Series:
AFC-3000 Automated Fraction Collector
Page 55