The following can be used as a guideline for regeneration/column cleaning for many reversed phase HPLC columns.
Rinse with 10 Column Volumes each of:
For instances of high back pressure it is permissible to "reverse- flush" Phenomenex columns. This practice should not be used on other manufacturers' columns, which may not be to similar standards.
Before starting any kind of cleaning procedure, make sure your in-column solvent or mobile phase is miscible with the recommended cleaning solvents. Also, flow-rates should be 1/5-/12 of the typical flow-rate
Column volume can be estimated using the following equation: