Chromatography Forum

I am using a C-18 column with a 30-90% acetonitrile/water gradient. A week ago I injected pure DMSO into HPLC system as a blank and my samples that are also in pure DMSO. After that analysis the column remained idle for one week. Now when I am trying to use it again the pressure keeps on increasing and at around 350+ bars the pump stops(max. pressure limit of pump is 400bar).When the lower end of the column is not connected to the tubing that goes to the detector, the pressure reads around 85 bars. The moment I connect that tubing the pressure starts skyrocketing and eventually the pump shuts off at 400bars. Any insights into what might be going wrong!

I am afraid that your detector was blocked. or the pipes that connect between your column and detector was blocked,so one thing you can do is connect the pipe to the end column but not to the detctor and find what happend ?if at this time the pressure does not rise ,that means your detector was blocked ,and you can clean the detctor .