| | Re: HPLC column clogging
What type of column is it?
When I have this problem, I will first try to clean with IPA (at ~.3mL/min) overnight. Disconnect the column outlet from your detector to ensure that you don't end up contaminating the detector.
Most modern columns can be washed backwards to get rid of particles at the head of the column. I do this with a low flow of IPA as well. You may want to call your column manufacturer to ensure that its okay to do this with your column type.
Last resort, Dichloromethane.
In the future, use a guard column if you can. They are much cheaper to throw away if they can't be cleaned.