Chromatography Forum

I would like to know if there a way to separate Helium from pure Neon for measurement with a TCD. Let me know which column to use with conditions.

Thank you

Dany

The only commercial column I believe that can resolve mole percent amounts of Ne and He at ambient temperatures is a long Carboxen 1000 column. The retention time separation is only about 10 seconds with a 6 meter column with a retention around 1.5 minutes at 40°C. Depending upon injection volume and concentration the separation may not be baseline. MS5A will not do as well from my experience.

I would special order 2 or more of these 4.5 meter columns with 10µm screens to minimize dead volume and butt them together with a bored through union, all available from Supelco.

I would also use room temperature conditions if possible. With subambient temperatures both the Carboxen 1000 and molesieve 5A should separate Neon and Helium.

I would also try MS4A if you can find it.

I would also use a valve injection instead of a syringe injection as you should see better results with a valve.

best wishes,

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
rodney.george@sial.com

Oops, thinking about it, why don't you just use helium carrier and mask the helium altogether, unless of course your helium is contaminated. But if it is really pure, then you should be able to see neon contamination. If it isn't then use nitrogen carrier for maximum response and use a small as possible sample injection to reach the detection limits you require.

I would like to see any chromatograms you produce, successfully or not, if you would be so kind.

best wishes,

Rod

Dany,

According to a literature reference, neon and helium are separated on a MS5A column, but the only details given are "normal temperature". No column ID or length or sample size is documented. I do not have the original reference which is:

Brian Thompson - Varian Associates Inc.
Fundamentals of Gas Analysis by Gas Chromatography, 1977

If you can find a copy fax or email me a copy of the chromatogram and the analytical conditions please.

I have found the commercial lots of MS5A differ in their separation attributes and are not always consistent.

best wishes,

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
rodney.george@sial.com

tigerk2001

I have separated Neon and Helium using a 9 meter MS5A column at 30°C.

best wishes,

Rod

tigerk2001

I have separated Neon and Helium using a 6 meter Carboxen 1000 60/80 column at 60°C, but 30°C is better.

best wishes,

Rod

tigerk2001

Did you see the posts I made?

Please acknowledge.

Thanks.

Rod