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GC column flow
Posted: Sun Sep 12, 2021 2:59 pm
by kiriakos
Hello,
What is the best flow for a column with the following dimensions?
30m*0.25mm*0.25μm
Thank you
Re: GC column flow
Posted: Mon Sep 13, 2021 3:44 am
by trozen
I would start from 1.5 mL/min, but it could be between 1.2 and 1.8 mL/min, depending on your application
Re: GC column flow
Posted: Tue Sep 14, 2021 2:08 pm
by kiriakos
Thank you trozen
Re: GC column flow
Posted: Thu Sep 16, 2021 5:57 am
by antonk
Re: GC column flow
Posted: Fri Oct 01, 2021 3:47 pm
by MK1
Optimum flow (giving the best resolution) depends on the carrier gas in use. With hydrogen & helium faster flows can be used with relatively little change in resolution, but column efficiency drops of fairly rapidly below the optimum.
As a rough guide a linear velocity of 10 cm/s is near optimum for nitrogen, helium's optimum is roughly twice this (20cm/s) & hydrogens near double again (40cm/s).
Look up 'Van Deemter' plots, for a fuller picture.