Chromatographic Performance - Thermo Scientific EASY-nLC 1200 Troubleshooting And Maintenance Manual

7
Troubleshooting
Troubleshooting Tips

Chromatographic Performance

Table 22. Troubleshooting tips for chromatographic performance
Symptom
Broad peaks
Poor retention time reproducibility
Sub-optimal analytical or
pre-column equilibration volumes
158 EASY-nLC 1200 Troubleshooting & Maintenance Guide
Table 22 lists troubleshooting tips for common chromatography problems.
Possible cause
Dead volume between the
column and emitter
Damaged column
Temperature fluctuations in the
laboratory
Back flow on flow sensor B
Spikes seen in flow sensor B
during valve shifts
Target pressure calculation is
affected.
Action
Check the connections.
Replace the fittings if needed.
Inspect the column, especially the outlet.
Replace the column if it is damaged.
Monitor the laboratory temperature.
Stabilize the temperature by keeping the
laboratory doors closed and by ensuring that
the air conditioning system is kept constant
at all times.
Do not run the EASY-nLC instrument with
the panels removed.
Run the Leaks script for Pump A, Pump B,
and System.
Replace defective piston seals, rotor seals,
check valve(s) for leakage and solvent lines as
indicated.
Use the scripts to check for a leak in the B
subsystem (Leak test Pumps A + B, and
System).
Replace defective seals, rotors, and solvent
lines as needed.
Use the correct equilibration volume.
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