WATERS CORPORATION 2424, Operator'S Manual, Page: 148 / 196

5-22 Diagnostic Functions and Troubleshooting
Abnormal baseline
Drift, noise, and cycling are common symptoms of an abnormal baseline.
Cycling
If the baseline is cycling, determine the period of the cycle and whether it is
related to the flow rate or fluctuations in ambient temperature or pressure.
Refer to the following table to troubleshoot problems with your baseline.
Abnormal baseline troubleshooting
Symptom Possible cause Corrective action
Baseline drift Mobile phase mixing
problem causing
improper
evaporation.
Correct mobile phase
composition. Use high-quality
HPLC water and organic
solvents.
Drift tube
temperature not
optimized correctly.
Recalculate temperature for
least volatile mobile phase
during a gradient run. Reset
temperature as necessary (see
page 3-18 ).
Column shedding
particles during
gradient run.
Recalculate temperature for
least volatile mobile phase
during a gradient run. Reset
temperature as necessary (see
page 3-18 ).
Baseline noise
(regular)
Air in mobile phase
or pump.
Degas mobile phase. Purge
pump to remove air.
Pump pulsations. Incorporate pulse dampener
into system.
Correct pump check valve or
pump seal problems.