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How to Configure the Optimum Delay Volume
The physical delay volume of the pump depends primarily on the use of the Jet
Weaver mixer. For UV detection the Jet Weaver should always be used but for
mass spectrometric detection the user can decide to bypass the Jet Weaver in
order to reduce the delay volume. This only makes sense for ultra-fast gradient
operation (less than 0.5 min) or for use with very small volume columns. If the
Jet Weaver is bypassed the connection tubing to the autosampler is routed
directly from the purge valve.
Before disconnecting a Jet Weaver from the flow path, flush it with organic solvent. Avoid
N O T E
leaving water or buffers inside the Jet Weaver, which may cause the growth of
microorganisms like algae or bacteria.
Sometimes it may be advisable to increase the delay volume in the pump.
Specifically this can be the case when UV detection is employed and a strongly
UV-absorbing compound has been added to the mobile phase. This can have
the effect of emphasizing any pump noise and the most common example is
the use of trifluoroacetic acid (TFA) in the analysis of proteins and peptides.
The effect can be mitigated by increasing the mixer volume.
The following different Jet Weaver configurations are available:
• The Jet Weaver 35 µL/100 µL(G4220-60006) has two alternative volumes in
• The 380 µL Jet Weaver high performance mixer is optionally available for
Agilent 1290 Infinity Binary Pump User Manual
the same unit.
The switch from the lower volume, 35 µl, to the higher volume, 100 µl, is
done by uninstalling it, turning it around from front to back and
re-installing it, see
"Changing configuration or replacing the Jet Weaver"
page 127. The mixing volume (and hence delay volume) is increased by 65 µl
and the baseline performance with additives like TFA will be improved.The
configuration of the Jet Weaver is logged automatically by an attached RFID
tag.
demanding applications, which use solvents in different channels (for
example A versus B), that differ strongly in their UV/Vis absorption, for
example by using trifluoroacetic acid (TFA) as a modifier, which has a high
absorbance.
How to Optimize the Performance of Your Module
How to Configure the Optimum Delay Volume
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