Chromatography Forum

Hi,

I operate a PerkinElmer Clarus 680 GC with TurboMatrix headspace sampler set up for Transformer Oil Gas Analysis (TOGA).

Recently I noticed a very noisy baseline over both the TCD and FID detector regions. Followed usual approach and increased over temperature to 'bake out' columns for an hour to no effect. Filters were recently changed and I tried 2x Argon bottles to remove the possibility of cylinder contamination.

Service engineer visited and it was noticed that the H2 combustion gas flow for the FID flucuated at least 0.5ml either side of the set point when previously it was extremely consistent. Engineer recalibrated flows and this appeared to solve problem...for 3 days until flow flucuation and baseline noise returned.

Has anyone seen this, could there be a fault with PPC module?

I have an old HP 5890A in my lab that requires me to set those support gas flows manually. I can tell you that I do not see appreciable differences in my baseline noise if the hydrogen flow is +/- 5 mL minute (30 is my target). I think that "fluctuating hydrogen flow" is not the source of your problem. In my experience, noisy baseline is usually linked to impure support gases. It could be electronic noise but first make sure that your air and hydrogen are clean.