OBJECTIVE or GOAL
Determine the source of a clog in the guard or column.
- First determine where the source of the clog is: guard or column? See How to determine if a pressure increase is due to a column or guard column
- Run mobile phase only through a fresh column. Does the back pressure go up over time or right away?
- If running just mobile phase through the column causes no increase, make blank injections as if you are injecting a sample. Does the back pressure go up over time or right away?
For additional information see Controlling Contamination in LC/MS Systems - Best Practices