AnsweredAssumed Answered

Temperature gradient for MSD transfer line (bakeout)

Question asked by koos on Aug 26, 2019
Latest reply on Sep 4, 2019 by Tim Strutt

Good afternoon,

 

I am investigating the possibility of measuring diketones in a matrix of glycerol, which has a BP of 290*C.

The column I'd like to use is the VF-624ms 30 x  250 x 1.4, with the idea that this column is in-house and has heat resistance up to 280*C isocratic or 300*C gradient.

The up to 300C will allow me to bake out the glycerol after each run, but in my preparation, I wondered what to do with the MS transfer line temperature.

 

If I would set the MS transfer line to the isocratic maximum of 280C, I'll just be left with a glycerol buildup inside the column. Or is the drop in pressure due to the MS vacuum enough to keep glycerol in the gas phase? And if I would set the MS transfer line at 300C it will bleed the column bone dry, creating active zones at the end of the column.

 

Is there any way to have the MS transfer line temperature increase in tandem with the GC oven temperature gradient?

 

I understand that a Headspace method or buying a different column with a higher heat capacity while being more polar would help but unfortunately, that is not a current option.

 

Thanks and have a good day!

 

 

Instrument:

7890B GC, 5977B MS, VF-624ms column (-40*C to 280*C isocratic, up to 300*C for gradient)

Masshunter GC/MS Acquisition B.07.04.226

Outcomes