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Pre-Bake Headspace Septa
Posted: Fri Mar 19, 2010 11:18 am
by WK
Hi All,
Does anyone pre-bake their headspace septa?
I have a few peaks from mine which I would like to get rid of when using
SPME.
Any suggestions? (I may try to source others).
I use aluminium with PTFE.
Regards
WK
Posted: Fri Mar 19, 2010 12:37 pm
by krickos
Hi
This link may help as it both covers temperature limits and compability issues:
http://www.chem.agilent.com/en-US/Produ ... ction.aspx
For routine analysis I/we do not prebake septa, but then again we do not go over 80°C in routine analysis. For some trace analysis I have heard people doing it but unsure how well it works.
Posted: Fri Mar 19, 2010 10:21 pm
by GaryR
Routinely, we don't bother too much about it, and don't see any problems from the septa. We use butyl rubber / PTFE.
We were advised by the supplier to place them in the oven at 100C before use, or, at the very least make sure that once a pack is opened that it not left open on the bench. They are little sponges which will absorb solvents quite readily.
We use a lot of MeOH and occasionally see MeOH peaks in the blank. Usually not big enough to worry about though, and not from the septa but usually from our solvent. ie empty vials don't usually have the peaks.
Like Krickos, most of our methods are relatively low temperature.
Posted: Mon Mar 22, 2010 1:31 pm
by WK
Hi,
Thanks for the replies - I will go ahead next time and pre-bake some septa at 100degC (I use 80degc for the analysis).
Regards
WK