Chromatography
High Performance Liquid Chromatography (HPLC)
Separates the components of a liquid sample on a packed column and measures each one as it leaves. The workhorse of pharmaceutical QC for assay, impurities and dissolution.
- Pharmaceutical
- Biotech
- Food & beverage
- Environmental
- Cosmetics
- Chemicals
TROUBLESHOOTING
Common problems, causes and fixes
High back-pressure
Likely causes
- • Blocked column frit or guard column
- • Precipitated buffer in tubing
- • Blocked in-line filter
What to do
- • Replace the guard column or in-line filter
- • Back-flush the column if the supplier allows
- • Flush the system with warm water to dissolve buffer salts
Pressure fluctuating
Likely causes
- • Air bubble in the pump head
- • Faulty or dirty check valve
- • Leaking pump seal
What to do
- • Degas mobile phase and purge the pump
- • Sonicate or replace check valves
- • Replace pump seals
Retention time shifting
Likely causes
- • Change in mobile-phase composition or pH
- • Column temperature not controlled
- • Flow rate error or leak
- • Column not equilibrated
What to do
- • Prepare fresh mobile phase exactly as per the method
- • Use the column oven
- • Check for leaks and verify flow rate
- • Equilibrate for longer
Baseline drift or noise
Likely causes
- • Contaminated mobile phase
- • Lamp near end of life
- • Air in the detector cell
- • Room temperature changes
What to do
- • Use fresh HPLC-grade solvents
- • Check lamp energy and replace if low
- • Flush the flow cell
- • Keep the instrument away from draughts and direct sunlight
Peak tailing
Likely causes
- • Column degradation or void
- • Secondary interactions with silanol groups
- • Mobile-phase pH close to analyte pKa
What to do
- • Replace the column
- • Use an end-capped column or adjust buffer
- • Adjust pH as permitted by the method
Ghost / extra peaks
Likely causes
- • Carry-over from a previous injection
- • Contaminated diluent or vials
- • Late-eluting peaks from an earlier run
What to do
- • Increase needle wash; run blanks
- • Use fresh diluent and clean vials
- • Extend run time or add a wash step
No peaks
Likely causes
- • Lamp off or failed
- • Injection did not happen (empty vial, needle blocked)
- • Wrong wavelength
What to do
- • Check lamp status
- • Check vial volume and needle
- • Verify method settings
In LimsPulse · Calibration Management
Keep every HPLC in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.