Chromatography Forum

Dear colleagues,
I'm conditioning (empty injection ) my column DB 624 ( 0.53x3 ) at a temperature of 40 degrees for 15 min then ramped by 50 degrees/min to 230 degrees holding for 15 min and observed spikes when the temperature commences ramping to 230 degrees as the photo depicted.
the strange thing is that the spikes appear only in the conditioning ( empty injection ) but disappear in the sample analysis.
before using this parameter I was conditioning the column with isothermal 175 degrees and the status was normal.

I'd be inclined to trim a bit off the injector end of the column and then bake it out overnight at or near the max temp for your program.

Every time I installed a column in our GCs, I EXPECTED there to be spiking for a while.

Every time I installed a column in our GCs, I EXPECTED there to be spiking for a while.

Yes, there may be very small particles of ferrule in the very last millimeters of the column. Another source of spikes is dirty FID. Small particles of dust may get into the flame causing spikes.
It's a pity we don't know what kind of detector was it.