Retention Time Symptoms; Retention Time Drift; Retention Time Wander (Reproducibility) - HP 5890 Series II Plus Reference Manual

Chromatographic Troubleshooting

Retention time symptoms

Retention time symptoms

Retention time drift

Retention time drift is a steady increase or decrease of retention times in
successive runs. Erratic times (both directions) are discussed below as
retention time wander.
1. In a series of runs, retention times suddenly increase:
2. In a series of runs, retention times suddenly decrease:

Retention time wander (reproducibility)

1. Retention time reproducibility is erratic throughout the run:
This may be due to an oven temperature change or to change in
flow; verify setpoints.
A blown septum is a possibility. If this happens, the change is
probably at the beginning of a run.
The carrier gas tank may be nearly empty.
This is likely to be due to a setpoint change, either in oven
temperature or in carrier gas flow rate; verify both.
If the runs are made with manual injection, the suspect is
injection technique. Variation in time between sample injection
and pressing
START
automatic injection this possibility is minimized.
Oven temperature variation may cause this; monitor oven
temperature during a run to check this.
causes variation in retention times. With
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