PDA detector issues


We are having problems with our PDA. Our read energy shows almost 0 counts below 230nm. We have changed the flow cell and lamp without any change.

Supposedly solvent B was filled with DMF instead of acetonitrile which seems to have caused the problem. This immediately caused high pressure in the system and the 210 maxed out completely before appearing to have no signal in following runs.

What can we try from here?


  • Bypass the column and flush the DMF etc. out. Once you have some reasonable combination of water and methanol in the flow cell, reset the PDA and see what your energies are reading. If your numbers are still very low, try a different lamp. If that does not help, you may have to have your window and/or grating replaced.
    Basically, you just work your from the lamp to the photomultiplier, replacing things that are crazed from the UV light until it starts working again. If the optical bench is good and results are still low, you probably need a new amp. board.