Waters HPLC - Page 101

Troubleshooting 3-17
Before using the table below, see “Troubleshooting steps” on page 3-2 to
isolate the cause of the chromatography symptom.
Chromatography troubleshooting
Symptom Possible cause Corrective action
Erratic retention time Air in pump head Degas all solvents,
prime pump, or check
sparge rate.
Malfunctioning pump
check valves
Clean or replace pump
check valves.
Leaking pump seals Replace pump seals (see
“Replacing the pump
seal” on page 3-58).
Separation chemistry Check mobile phase and
column.
Clogged solvent filter Replace filters.
Increased retention
times
Incorrect flow rate or
solvent composition.
Change flow rate or
solvent composition.
Doubled retention times Air bubble in pump
head
Prime pump to remove
bubble.
Malfunctioning pump
check valves
Clean or replace check
valves.
Broken pump plunger Replace the plunger.
Reduced retention time Incorrect flow rate Change flow rate.
Incorrect solvent
composition
Change composition.
Incorrect mobile phase Use correct mobile
phase.
Column contaminated Clean or replace
column.
Incorrect column Use correct column.