Re: GC 5890 FID/Purge and Trap Baseline Drift Problem
Posted: Tue Oct 15, 2013 3:32 pm
You have a 1/16 inch swagelok at the end of the transfer line. The only extra materials you need to connect the column to the transfer line is a 1/16 inch swagelok nut and a 0.8 mm ferrule. You work with 0.53 mm i.d. columns, so you must have 0.8 mm ferrules somewhere, and I would be surprised if there is not a 1/16 inch swagelok connector somewhere as well.
The most likely cause for the contamination is the inlet septum. By making a direct connection between transfer line and column you eliminate not only the septum but also the dead volumes in your current set up.
Despite what your supervisor says, you should have a purifier in your carrier gas line.
Peter
You were very right Peter. I have run my GC with my inlet disconnected. I got a flat baseline. This is my chromatograph
I am running a RT Marker right now to see what the effect of having no inlet will be.