Page 1 of 1

Acetaldehyde

Posted: Thu May 03, 2007 12:16 pm
by pseudotexan
I am trying to separate Acetaldehyde from a balance of Isobutylene. I can't get it far enough after it to do a good separation. Does anyone know how to get it in front of the Isobutylene. I am currently using 10% Carbowax 20 M on Chromosorb W HP. Any suggestions would be greatly appreciated.
Thanks
Paul

Posted: Thu May 03, 2007 3:22 pm
by chromatographer1
A trifluoropropyl methyl silicone column should do the job.

You could also try a 1% Carbowax 20M on Carbopack B or 1% TCEP on Carbopack B. should reverse order the elution.

best wishes,

Rod

Posted: Thu May 03, 2007 3:27 pm
by pseudotexan
How about Haysep D. Any idea of the relative rt of isobutylene on that one? Acetaldehyde should come out very early on that.

Posted: Thu May 03, 2007 3:41 pm
by chromatographer1
It should be fairly close.

If there is no water in your stream I would try the trifluoromethyl silicone first.

Then try Q or D Porous Polymer. It may take more than 6 ft of column.

Then try the Carbopack B.

Are you trying to measure less than 500 ppm?

Good luck.

Rod

Posted: Thu May 03, 2007 3:46 pm
by pseudotexan
Yes I am looking for about half of that in a balance of Isobutylene which is why I am trying to get in front of it. I am having no luck heartcutting it out and it is driving me crazy!!!

Posted: Thu May 03, 2007 3:52 pm
by chromatographer1
If capillary were possible a LOWOX from Varian or a Oxyplot from Agilent would be an obvious choice.

Process applications used to keep me up at night.

Keep having fun (to steal a line from another chromatographer) !

Guess what, you might try a high loading of methyl silicone or Apiezon L.

There is 28°C difference in boiling point.

Good luck.

Rod