Hi AICMM,

I appreciate your input and advice, but I again find myself questioning whether a makeup gas is really needed for the PE FID.... The operator's manual talks about makeup gases for ECD, but there is nothing at all mentioned in the section for FID. There is not even a connection to attach a makeup gas line to the FID detector itself.

Anyway, here's the latest chromatogram I am getting. This is after baking off the detector at 380°C. I think this is fixed.

Image

Thanks for your help....