Waters Prep Series Installation And Maintenance Manual page 106

Chromatography troubleshooting (Continued)
Symptom
Flat-topped peaks
Sensitivity loss
3-22 Troubleshooting, Testing, and Maintenance
Possible cause
Detector not zeroed
Incorrect recorder input
voltage
Sensitivity too high
Sample concentration
or injection volume
exceeds voltage output
of detector
Leak in injector
Degraded,
contaminated, or
improperly prepared
sample
Column contaminated
Loss of column
efficiency
Peaks wider than
expected
Incorrect Filter
Constant
Change in mobile phase
composition
Leak in flow cell
Incorrect flow rate
Corrective action
Zero detector baseline.
Adjust recorder input
voltage, or adjust
detector output cable to
proper position.
Select a less sensitive
detector range.
Decrease sample
concentration or
injection volume.
Troubleshoot injector.
Use fresh sample.
Clean/replace column.
Clean/replace column.
Troubleshoot injector.
Set correct Filter
Constant value on
DETECTOR SETUP
screen.
Correct mobile phase
pH or ionic composition.
Tighten cell seal.
Change flow rate.