Chromatography Forum

Hi,
I'm newbie GCMS user, by mistake I injected second sample into GC after finishing first run, when oven temperature was still at 60C and was coming down to set 30C. However, after completely finishing first run, second run started (I didn't see live chromatogram for this, even after finishing second run). But, now I'm having issue of "GC not ready" when i checked status on GC panel, it says, "WAITING FOR PREP RUN, FRONT INLET PURGING".
I tried to fix this issue by pressing "Prep run" button manually, and GC got ready for next run but chemstation showing the same "not ready" message (Sorry, couldn't attach the Fig).

Cheers,

Faray

Hi,
I'm newbie GCMS user, by mistake I injected second sample into GC after finishing first run, when oven temperature was still at 60C and was coming down to set 30C.

Not easy at all to get a GC oven to equilibrate at 30C after a programmed run, especially when the inlet, the detector are hotter than that. And the room could be warm, that doesn't help. And that's assuming that the GC fan, flaps, etc. are operating properly.

You may want to set the Oven Equilibration time to 5 seconds (or 0.1 minutes ) so it doesn't wait too long once getting to such a low temperature. It will approach that temperature slowly enough that it is at equilibrium anyway.

Also if you halted a run prematurely and it is now giving problems you may want to close down the software, reboot the computer and turn the power off and back on on the GC just to make sure everything is synchronized.