4 Replies Latest reply on Mar 14, 2019 3:17 AM by dmarchini

    Column replacement


      Hi there,


      I had to change the column of my GC-6850 couple of days ago.

      While changing it I noticed that the ferrule on the detector side needed to be replaced.

      The new ferrule would arrive in about 2 weeks only and I could not wait for that, so I had to position the nut & old ferrule back on the New column.

      To do that I had to slide the column nut attached to the ferrule all the way through the new column.


      I just wanted to know what are the chances that I could have damaged the column doing that.


      Thank you so much.

        • Re: Column replacement

          Hi elirodrigues,

          I updated the tags for better visibility. In a pinch, you can use the old ferrule if you can get it to seal. In any case, the suggestion I would have after viewing the picture would be that you cut a few cm's off the front of the column to avoid any ferrule particles causing you problems after you have pushed the column through the ferrule.



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            • Re: Column replacement

              Thank you for that James.

              I actually have trimmed the column when I finished pushing the nut and ferrule through the column.


              Saying that, I assume my contamination could be sitting at the inlet port of the GC.

              • Re: Column replacement

                Hi Eli


                From the photo it seems that the ferrule has extruded quite a bit (over tight nut?) and thus I would also consider replacing the septum, liner and gold seal. I would also clean the injector with MeCl2 and acetone. I find that the graphite/vespel ferrules works best for me and even better would be to change to self-tightening column nuts.


                Good luck.

                2 people found this helpful
              • Re: Column replacement

                I think you overtighted the nut, and pure graphite ferrules tends to "splat" like these ; I stopped years ago using graphite ferrules, now i use only graphite/vespel ones.


                You can slide up your column in the nut then cut 2 inches avoiding to use the column full of ferrules particles, then set the right lengt (dependin if you are goin on detector or injector)as seen in


                markin the column at the bottom of the nut with a marker then install it, try to not overtight the nut.

                2 people found this helpful