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Looking for

Posted: Mon Oct 02, 2006 3:41 am
by raustin
Building a field use gas chromat for hydrocarbons c1-c5. Any sourcing or reference material for constructing a 1/4" od poly flo column 6-8 ft long squalene packing how to.
:roll: Thanks

C1-C5 Hydrocarbons

Posted: Mon Oct 02, 2006 12:10 pm
by chromatographer1
This analysis is usually done on a non-polar column like the squalane you mentioned.

But for speed a micropacked column would be a better alternative.

Supelco and other vendors are quite experienced in packing any kind of packed column you wish to use more reproducibly most likely than you or other novices are able to at a low cost.

Can you clarify what a poly flo column is and which support you wish to use? Are you looking to use teflon tubing? What kind of column packing enclosure do you want? Glass wool, quartz wool, stainless steel screens?

Do you want teflon or fused silica lined SS? Glass? If you wish to discuss give me or techservice@sial.com a call or note and we will be happy to assist you.

I have done C1-C5 in as little as 30 seconds, but usually an analysis will take 2 minutes or more.

Rodney George
Senior Research and Development Scientist
Gas Separations Research
Supelco
595 North Harrison Road
Bellefonte, PA 16823

814-359-5737 voice
814-359-5459 fax
rgeorge@sial.com

Re: Looking for

Posted: Tue Oct 03, 2006 3:45 am
by Bruce Hamilton
Building a field use gas chromat for hydrocarbons c1-c5. Any sourcing or reference material for constructing a 1/4" od poly flo column 6-8 ft long squalene packing how to.
I'd suggest you consider starting again. Ployflo is a polyethylene tubing that's thermoplastic. If you can't use the conventional GC column materials, then you need to choose a material that is impervious and can also cope with thermal conditioning of the column. If your system is disposable, then nmaybe PE would be suitable, but the alternatives aren't expensive.

Typical tubing is Stainless steel - no good for acid/corrosive gases; silica or glass - very common, and also possible to use alumina in a porous layer open tubular silica column; or PTFE - good if reactive compounds eg sulphur, are present).

Whilst an unsaturated hydrocarbon like squalene can be used as stationary phase, there are also more durable alternatives, such as Carbopack. I'd suggest looking at the catalogues of somebody like Restek, Supelco, Agilent for more details of possible systems.

There are small field GCs available for low molecular HCs, and the chromatographic systems depend on what process/environment you are sampling and what concentrations you want to detect. If you describe your needs, maybe somebody can offer more specific suggestions.

Bruce Hamilton