HPLC Troubleshooting - Fluctuating Pressure

If you notice your LC system is experiencing fluctuating pressure; the following causes may be responsible.

Causes	Solutions
Air bubbles	- Purge the solvent lines to remove the air bubbles.
Worn pump seals	- Replace seals.
Check valves	- Sonicate the check valves in isopropanol. - Change the check valves if problem persists.
Leaks	- Degradation of pump seals could cause small leaks. Replace the seals. Check connections.
Inadequate degassing	- Degas solvent; replace mobile phase frits; repair degasser (if applicable).
Using a gradient elution	- Pressure cycling caused by viscosity changes is normal but, use adequately sized mixer volume.