Chromatography Forum

Hi folks,
I need to analyse a mixture of several low molecular weight compounds including acetone, isopropyl alcohol, butyric acid and mercaptoethanol.
(you can imagine it doesn't smell great). I'm using a 30m 0.25x0.25 wax column. Will it be possible to separate such a mixture with this column?
What would be an appropriate solvent? I was thinking DMSO. I'm using GC FID with Hydrogen carrier gas 45cm/s.
Thanks
Rick

Hi

Well this will be a half qualified guess, but after looking at some of Agilents/J&W chromatograms for WAX columns, you should be able to separate them, a bit unsure where the mercaptoethanol would end up though.

So a WAX column would like be worth a shot. However I suspect that the filmthickness could be an issue (0,25µm), in my experiance thinner films on WAX columns are not very inert and may cause peak issues for the acid and potentially the mercaptoethanol, would suggest a 1µm filmthickness instead.

Solvent. Well DMSO (bp 189°C) wont give you much of a solvent effect if you do normal split injection.
As someone pointed out earlier in this forum, CS2 is sometimes underestimated, elutes early and have no repsonse in a FID. Was a long time I used it myself but could be worth a try, elutes approx 1min before acetone on a WAX column 1µm film at 40°C isotermal.

Sextonrick,

As krickos suggests, I would push a thicker film....

As an alternative you might look at a VOA type column, RTX-VMS, DB-624, etc....

Best regards.