NEWS CENTER
Why Does HPLC System Pressure Suddenly Increase?
Release time:
2026-01-15
A sudden increase in system pressure is one of the most common alarms encountered during HPLC operation. Many users immediately worry about pump failure or column damage. In most cases, however, pressure issues are caused by blockages or changes within the flow path and can be resolved with systematic troubleshooting.
1. Column Blockage or Contamination
The most frequent cause of high pressure is blockage inside the column.
Possible reasons include:
Particulate matter from unfiltered samples
Precipitation of buffer salts
Strongly retained compounds accumulating over time
As contaminants build up, flow resistance increases, leading to elevated system pressure.
Best practice:
Always filter samples and mobile phases
Use a guard column
Flush the column regularly with appropriate solvents
2. Blocked Inline Filters or Tubing
Inline filters, frits, and capillary tubing can gradually collect particles.
Symptoms include:
Rapid pressure increase
Pressure instability
Normal pressure after column removal
Best practice:
Disconnect the column and check pressure without it
Clean or replace inline filters
Inspect tubing for blockages or kinks
3. Mobile Phase Incompatibility
Pressure problems can occur when mobile phases are incompatible.
Common situations:
Mixing high-percentage aqueous buffers with strong organic solvents
Sudden changes between different solvent systems
Salt precipitation in high-organic conditions
Precipitated salts can block both tubing and column frits.
Best practice:
Gradually change mobile phase composition
Flush the system with water before switching solvents
Avoid exceeding buffer solubility limits
4. Column Temperature and Solvent Viscosity
Lower temperatures increase solvent viscosity, which raises system pressure.
Possible causes:
Sudden drop in lab temperature
Column oven turned off
Use of highly viscous mobile phases
Best practice:
Maintain stable column temperature
Use a column oven for reproducible pressure and retention time
5. Pump and Check Valve Issues
Although less common, pump-related problems can contribute to pressure abnormalities.
Potential issues include:
Sticking check valves
Worn seals
Incomplete pump priming
These issues may cause pressure fluctuations rather than a smooth increase.
Best practice:
Prime the pump thoroughly
Perform routine maintenance according to the service schedule
Conclusion: Pressure Increase Is a Warning, Not a Failure
A rise in HPLC system pressure is usually a protective signal, indicating restricted flow somewhere in the system. By isolating each component — tubing, filters, column, and pump — the root cause can be quickly identified.
Routine filtration, proper solvent handling, and preventive maintenance are the most effective ways to avoid pressure-related issues.
BIKAI supports users with troubleshooting guidance, consumables, and maintenance solutions to ensure stable and reliable HPLC operation.
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