Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual page 111

Problem
Analysis run takes a
long time to start or
does not start at all.
Strong noise, non-
periodic baseline
fluctuation/
the Raman S/N value
cannot be met
Periodic baseline
fluctuation, pulsation
Peak tailing
Vertical lines in peak
Peak broadening,
peak tailing,
increased dead time
Operating Instructions
Fluorescence Detectors FLD-3100 and FLD-3400RS
Probable Cause
The flow cell is still being
preheated.
The eluent is dirty or their
purity is insufficient.
The detector is defective.
The lamp is too old.
Incorrect signal parameters
were selected.
The flow cell is contaminated.
The water is degraded.
There are pressure fluctuations
from the pump.
There are air bubbles in the
system.
Too large extra column volume
There are bad capillary
connections.
Flow cell input and output are
exchanged.
The detector had to
automatically adapt the
Sensitivity. The peak is marked
by several lines.
The inner diameter of the
capillary to the detector is too
large.
There are bad capillary
connections.
Too large detector cell. The
volume of the detector cell
should not exceed the smallest
peak volume by more than
1/10.
The filter frits on the solvent
lines are clogged.
UltiMate 3000 Series:
Remedial Action
Check the set flow cell temperature. At
high flow rates, the flow cell may not
reach the desired temperature. Select a
lower temperature.
Use fresh eluent. Use fluorescence-
grade eluents only.
Contact Service.
Contact Service.
Also observe the guidelines for
optimizing the parameters (→ page 81).
Select suitable wavelengths
(→ page 78).
Flush the flow cell (→ page 109).
Use fluorescence-grade water.
Purge the pump; check general function
(→ Pump Manual).
Purge the system.
(→ Pump Manual).
Use short capillary connections with a
suitable inner diameter.
Use different capillaries, for example,
Viper capillaries.
Verify that the flow cell input and
output are connected correctly.
Select a lower sensitivity. Check the
Chromeleon Audit Trail to find out
whether the Sensitivity was adjusted
automatically.
Change the capillary.
Use different capillaries, for example,
Viper capillaries.
Use a smaller volume flow cell (micro
flow cell).
Check the filter for permeability.
Replace the filter frit if necessary
(→ Pump Manual).
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