Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual page 109

Problem
Poor peak area precision
(Cont'd)
No flow
Operating Instructions
Probable Cause
The sample is unstable and
decomposes.
Baseline fluctuations
The environmental conditions are
unstable.
Contamination occurs
somewhere in the system.
For additional causes, see the
Autosampler manual.
The system is leaking.
The solvents are degraded, dirty
or of poor purity/quality.
Contamination occurs
somewhere in the system.
One or both valve cartridges are
not installed correctly (not in the
direction of flow) or are
defective.
There are air bubbles in the
eluent or in the pump head.
The static mixer in the purge unit
is blocked.
There are air bubbles in the flow
path.
UltiMate 3000 Series:
LPG-3400XRS Pump
Remedial Action
Use new sample or change the
conditions. Cool the sample
in the autosampler if possible.
See the remedial actions
provided in the related
baseline sections further up in
this table.
Make sure that the
temperature and the humidity
are constant. Avoid draft.
Consider using a
thermostatted column
compartment.
Flush the system using an
appropriate solvent.
→ Autosampler manual
Find and eliminate the leak.
Use fresh solvent. Use fresh
and appropriate solvents (at
least HPLC grade).
Flush the system with an
appropriate solvent.
Install the cartridges in the
direction of flow or replace
the cartridges if necessary
(→ page 124).
Purge the pump (→ page 62)
and check the degasser.
Replace the purge unit
(→ page 125).
Perform a wash cycle
(→ Autosampler manual).
Non-degassed wash liquid is
used. Degas the wash liquid
(→ Autosampler manual).
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