ghost peak after bake out
Posted: Wed Mar 13, 2013 2:53 am
We are running a Shimadzu GC-2014 with a methanizer unit, TCD and FID using HayeSep Q, PoraPak Q, and Molseive 5A packed columns. After noticing that the retention time of our methane standard was decreasing, a sign which normally indicates that CO2 from our process gas has begun to clog up the MS-5A column, I increased the oven temperature to 180C and left it running over night to try to regenerate the column and bake out any residual CO2. Upon returning the next morning, I found that there was a large ghost peak which appeared in blank runs. The peak has the same retention time as CO, and does not appear if the methanizer is shut off. Any thoughts as to the origin of this peak and how I can eliminate it?
The only gases going into the system are N2, CO2, CO, Methane, and possibly trace amounts of methanol.
The only gases going into the system are N2, CO2, CO, Methane, and possibly trace amounts of methanol.