Hi Hil,


The best column (imho) for separation of permanent gases is the
CarboPLOT P7, or its latest incarnation, the CarboBOND. Either way, this
column is only available as megabore (= 0.53mm ID), so backpressure is
not as bad as for a MolSieve 5A with an ID of 0.32mm. However, this is
still a PLOT column and, hence will be sensitive to sudden changes in
pressure and will show a back pressure higher than a WCOT megabore.

Having said all that, your application is decidedly different and even a
megabore column won't be an option. You can try HayeSep A (80/100 mesh)
or HayeSep DB (100/120 mesh). A SS tube (say 30' x 1/8") packed with
either can be run at 25-30 ml/min He at a pressure setting of about 90
psi and a resolution of N2 from CO of about 1 min (at a column T of
about 160 C, give or take 20).


Hope this helps.


Cheers,

Wolfram


> -----Original Message-----
> From: Stable Isotope Geochemistry
> [mailto:[log in to unmask]] On Behalf Of Hilary Stuart-Williams
> Sent: 23 February 2004 22:45
> To: [log in to unmask]
> Subject: What GC column for CO separation?
>
>
> Could I ask what columns people are using to separate CO from
> N2 after pyrolysis?
>
> I am using an Alltech 5A mole sieve in a 1/4" SS tube at the
> moment and the separation is good, but I'd like to get the
> back pressure down if possible.
>
> Is there anything new out there (after seeing the previous
> discussion)?
>
> Hil
>
> .
>
> Hilary Le Q. Stuart-Williams PhD.
> Research Officer in Stable Isotopes
> Environmental Biology Group
> Research School of Biological Sciences
> Australian National University
> Canberra, ACT, Australia
> (02) 6125 2099
> Personal home: www.webone.com.au/~hnksw
>