Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual page 112

UltiMate 3000 Series:
Fluorescence Detectors FLD-3100 and FLD-3400RS
Problem
Peak broadening,
peak tailing,
increased dead time
(Cont'd)
Reproducible ghost
peaks in the
chromatogram.
Some broad ghost
peaks in the
chromatogram.
Spikes
Page 104
Probable Cause
The capillaries are clogged, or
capillary connections bad.
The sample loop is clogged.
The proportioning valve is
defective.
The column is overloaded or
contaminated.
The solvent is degraded.
Flow cell input and output are
exchanged.
The selected response time is
too large.
The degassing channels are
contaminated.
The solvents are degraded or
dirty or their purity is
insufficient.
Contamination occurs
somewhere in the system.
Late eluting peak from
previous analysis.
There are air bubbles in the
flow cell.
The detector lamp is old or not
properly installed.
Electrical interferences from
other instruments.
The column temperature is
significantly above boiling
point of the mobile phase.
The flow cell temperature is
near the boiling point of the
mobile phase.
Remedial Action
Replace the capillaries. Use different
capillaries, for example, Viper
capillaries.
Replace the needle (→ Autosampler
Manual).
Contact Service.
Clean or replace the column.
Use fresh solvent.
Verify that the flow cell input and
output are connected correctly.
Select a suitable response time, e.g.,
using the Chromeleon Program Wizard
(→ Fig. 31).
Rinse the degassing channels
(→ Solvent Rack or Pump Manual).
Use fresh and appropriate solvents.
Flush the system with an appropriate
solvent.
Extend the run time. Increase the elution
strength of the gradient (higher organic
content). At the end of the run, flush
column with strong eluent.
Check all fluid connections for
tightness. Degas the mobile phase.
Contact Service.
Isolate the electrical circuit from strong
current consumers. Consider using an
UPS (Uninterruptible Power Supply) to
filter current fluctuations.
Install a backpressure regulator at the
flow cell outlet. Install a post-column
cooler (→ TCC-3000RS Manual).
Turn off the flow cell heating.
Operating Instructions