Chromatography Forum

hi all...
i need help and solution for my GCMS (7890)
it takes almost 6 hours to inject one sample to the other sample. can i adjust it?
one more thing, the inlet pressure always unstable..when this problem accur i usually change/clean the copper tubing. is there any solution for the pressure?

So the problem is that the inlet pressure isn't stable enough for the GC to go into ready state. Either the inlet is leaking or the supply gas is restricted. I would always start with the assumption that there is a leak unless the supply plumbing is new.

There is a setting for delay time on the GC to go to ready state but that isn't likely to be your problem. If the pressure isn't stable then your conditions won't be reproducible.