2 Replies Latest reply on Dec 18, 2018 1:43 AM by dmarchini

    Negative peaks in gas analysis with Agilent 490 Micro GC



      lately i have negative peaks problem with my Agilent 490 Micro GC, set up is:


      -helium carrier gas

      -moisture/oxygen filter

      -column 4m 5CB heated injector

      -micro TCD detector


      I analyze a gas stream from the production site, mainly nitrogen polluted with hydrocarbons.


      The micro GC is installed since 1year and a half and works 24h a day, I occasionally shut it down or bake the system like one times a month.


      Could be the inline GENIE 170 filter? I never changed it.


      Thanx, help is appreciated