I have an issue 1100 HPLC. The retention time is shifting. I changed the station pump, the needle, the needle seat, the column, the seal rotor, and the guard. The issue continues. Some ideas and recommendations.  


Parents Reply Children
  • So, you checked the flow and it's okay.

    If flow at outlet of dain line is okay and constant then complete system flow is okay..

    How much is flow.

    Make sure, mobile phase is not contaminated..

  • If we assume that system is ok( generally propotional valve/ check valve/ no bubble in line/sample loop is not over loaded/ no leak/constant flow/ no pressure variation) then this problem may link with some chemical related.

    I will suggest use new mobile phase and condition this new column with new mobile phase at least 10 to 12 hour.After that run sample to see repeatability n RT..

Was this helpful?