flow rate(He) of GC/MS for different inner diameter?

[guoyang]

Hi, everyone!
I use aglient 7890-5975C GC/MS. I want to know how to set flow rate(He) of GC/MS for different inner diameter capillary column?
Thanks!

[haiedc]

The flowrate in GC/MS is determined by MSD which is appr. 1.0ml/min (can be 1.5) for best performance. So you can not use megabore columns (eg. 0.53mm). Even 0.32 mm column is not good (and not possible for short columns).

[Don_Hilton]

Ideal linear velocity in a column is about 23 cm/sec. With a 0.32 column, you can do this, but the column needs to be long enough that the pressure drop will allow the inlet to be operated at above atmospheric pressure. If running your column at optimum velocity delivers more gas to the mass spec than the pump can handle, you need a narrower column. Pumping capacity of a mass spec is determined by the pump in use on the mass spec. Check the specifications.