Chromatography Forum

Hi, I am a beginner to GCs and I was setting up for the first time a 6890 GC with an FID detector. I was hoping someone can direct me on the gas lines. I got three gases as the FID states but I cannot figure out what goes onto the three openings for the front inlet. I am attaching a few pictures. We were not planning on using the back inlet at all. Do I need to Y some gases to the inlet openings? I numbered them 1, 2 and 3.

Thank you very very much for your help!

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This looks like an Agilent 6890.
#1 is for the carrier gas, you might need to tee into one of the other connections.
#2 is the split/splitless vent; either leave it unconnected or add an organics trap.
#3 is the purge vent; either leave it unconnected or add an organics trap.