Acetaldehyde

[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

[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

[pseudotexan]

How about Haysep D. Any idea of the relative rt of isobutylene on that one? Acetaldehyde should come out very early on that.

[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

[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!!!

[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