Here are some common troubleshooting issues in HPLC and their explanations:
1. High Backpressure
- Cause: Clogged column, blocked frit, or too viscous mobile phase.
- Solution: Check and clean the column, use proper solvents, filter samples.
2. Poor Peak Shape (Tailing or Fronting)
- Cause: Column overloading, degraded stationary phase, or incorrect mobile phase pH.
- Solution: Reduce sample amount, check column condition, adjust mobile phase.
3. Baseline Noise or Drift
- Cause: Air bubbles in the mobile phase, impure solvents, or detector issues.
- Solution: Degas solvents, use high-purity solvents, check detector settings.
4. Retention Time Shifts
- Cause: Changes in mobile phase composition, temperature, or flow rate.
- Solution: Standardize conditions, maintain column temperature, ensure consistent flow.
5. Low Sensitivity
- Cause: Detector settings incorrect, column contamination, or analyte degradation.
- Solution: Check detector wavelength and settings, clean or replace column, use fresh sample.
6. Ghost Peaks or Extra Peaks
- Cause: Contaminated solvents, sample carryover, or degraded column.
- Solution: Use clean solvents, wash injector, check and maintain column.
7. Bubble Formation
- Cause: Air trapped in the mobile phase or pump system.
- Solution: Degas solvents, check pump seals, purge system before running.
In short:
Most HPLC issues are caused by column problems, mobile phase issues, detector settings, or sample impurities. Regular maintenance, proper solvent handling, and careful sample prep prevent most problems.