Peak broadening towards the end of a GC run.
Posted: Mon May 27, 2019 2:34 pm
by colan005
Dear all, Please I need help, I am experiencing peak broadening towards the end of my GC run. The total run time is about 50 min. The peak broadening starts around 30 min resulting to poor separation of compound. Please kindly advice.
Re: Peak broadening towards the end of a GC run.
Posted: Tue May 28, 2019 12:25 pm
by rb6banjo
Can you post an image of your chromatograms where you are seeing this behavior? Also, the more you can give us regarding your method and your analytes, the better we can address your problem. Lots of folks on this forum have lots of experience and have seen a few things come and go.
If you are running with constant pressure, you will see broadening because the flow rate of your carrier gas changes with temperature (slower when oven is warmer).
Is it possible you're seeing carryover from a previous injection? That's a pretty long run so I assume you're sitting at a hot temperature for a while.