What pressure can be used with HPLC columns?
Silica-based HPLC columns can operate at pressures up to 4000psi, except for anything over 4.6mm ID, then operate at pressures less than 3000psi. Resin-based columns are limited to much lower pressures. You can expect a gradual increase in backpressure as the column ages. A sudden increase in pressure usually means that there is a plugged/blocked frit at the column inlet. To unplug/unblock the frit, reverse the column and flush with an appropriate solvent, with the column disconnected from the detector.
