3 Replies Latest reply on Jun 13, 2018 5:36 AM by james_jenkins

    GC-FID random solvent broading

    dmarchini

      Hello guys

      we got a new Agilent 7890B one month ago; after installing the columns it happens this random solvent broading in FRONT and BACK section.

      We reinstalled the columns but the problem is still there.

       

      What we have to check again?

       

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        • Re: GC-FID random solvent broading
          james_jenkins

          Hi dmarchini,

          It looks like solvent hanging around in the inlet. I checked the vapor volume and its good at around 320ul . I do notice that the total flow is below what we recommend for effective use of a split/splitless inlet.  Typically the inlet is happiest at 20ml/min. A couple of things to try , one at a time. Turn on your septum purge , default is at 3ml. If you really need a 10:1 split ,you could also turn on gas saver at 1 minute (or other times as you experiment) which would get the total flow to what we recommend operating the inlet at and help sweep the residual solvent away. Last would be to increase the split to get the total flow up to the 20ml, but you may sacrifice some sensitivity . I hope this helps.

          Regards

          James