Column Advice...

[SkylineGTR112]

I am trying to find a column that can get good separation of Argon/Oxygen/Nitrogen and still be able to handle CO2. Any of you guys have any suggestions?

[TimGG]

Hi GTR, i think this one might work~~

Rt-Msieve 5A PLOT

Here's the link for more info~~~ enjoy

http://www.restek.com/aoi_petro_A009.asp

[SkylineGTR112]

I've always been told that you can't run CO2 through a Molsieve because it will be retained by the column and poison it.

[CE Instruments]

We have supplied numerous system to analyse O2, N2 and Argon in CO2. I would be delighted if anyone could find an easy solution. We do this either by trapping and backflush of the CO2 on a Porapak type column , or twin channel with detection of the eluant of the Porapak to another detector both with Molsieve for Oxygen, Argon, Nitrogen separation, or we even set up analysis on a Porapak column in liquid Nitrogen , removing the liquid Nitrogen every few runs and eluting the reatained CO2

[chromatographer1]

The Restek solution required a helium ionization detector. A TCD will not work. and if your sample is larger than 5µL you may overload the column.

To separate all these gases you need a MS 13X column at ambient temperatures or a 5A column if you can heat your oven to 200°C.

You can also use a 15 to 30ft Carboxen 1000 column but argon separation would require sub-ambient temperatures if it is possible.

The best ambient or low temperature solution with a TCD is 13X but Argon separation from oxygen is minimal.

Using multidimension chromatography and good packed columns, a 2 meter Porapak Q and a 9 meter MS 5A will separate all the peaks (with a backflush to remove heavies) at 20-30°C.

best wishes,

Rodney George
consultant