Chromatography Forum

Has anyone ever heard of a GC-column coated with a thin layer of metal? if so, how would it be made?

Historically, some fused silica columns were made with a coating of aluminum instead of polyimide. While having a higher temperature limit, after stressing the material with heating and cooling cycles the metal tended to separate from the fused silica, causing the column to break.

They may be available on a custom basis. The manufacturing process would be proprietary, would it not?

i was thinking more along the lines of nickel or palladium or so. I would have thought the coating you mention was aluminum-oxide. As for the manufacturing, I'm sure you are right.

We have used aluminum-clad fused silica columns in the past for high temperature work (they got brittle after a few YEARS. Now we use stainless steel capillaries, available from Quadrex or Restek. They're very useful for high boiling stuff.

i should make myself more clear: i want a thin layer of metal coated on an inert column wall (fused silica). The idea is to use the column as a reactor / seperator.

Do you mean on the inside of the column instead of a polymeric stationary phase? If so, there is nothing commercially available that I have ever heard of. If I was to do this I would try using a narrow bore tube made of the metal. Coating the interior of a capillary column with a uniform coating of a metal would certainly be a challange.

Alumina columns are available from several vendors, they usually have some sort of salt added, Chloride or Sulfate to modify the activity of the alumina and improve the performance.

I won't plug my company's product because you may have a special need that they (or anyone's) will not meet.

Give a better idea of what you wish to achieve and I believe you will receive more helpful answers from the forum members.

hi
you can use stainless steel capilary or wide-bore colomns
they are very good
arie

martinz,

At the risk of misunderstanding what is going on, if you are trying to get a reaction to happen on the metal surface prior to chromatography, how about loading something into the injection liner? I remember the old days when there was a water analysis where the injection port held calcium carbide, the water reacted to give acetylene, and the acetylene was detected with an FID. Maybe there is something similar you could do in the injection port?

Just a stray passing thought,
Regards,
Mark