Helium with GC/TCD

[xxx]

Does anyobody analyse He with a TCD.
Do you have a column suggestion?

I will try to analyse a mix of He and O2

[chromatographer1]

A molecular sieve packed column is generally the most effective and straightforward solution.

If water is present in your helium sample you may wish to use a Carboxen 1004 column. (2-3 meter 0.040" ID 1/16" OD)

If your gas is dry then a molecular sieve 5A column should be adequate.
(10ft 1/8" OD 0.084"ID ) The smaller the mesh size the better the separation. As a minimum use 80-100 mesh.

I assume you know to use nitrogen or argon as a carrier gas.

For really low levels of contamination you may have to try other detection methods. See your supplier of gases for their solution.

Be sure you condition your 5A column for a minimum of 16 hours @ 300°C or even 400°C with dry carrier gas flow before using.

Good luck.

[xxx]

Hi and thanks

I saw application from restek with megabore column and H2 as carrier gas,and a Msieve 5A Plot column.

What do you think about that?

[chromatographer1]

Well, a capillary column will cost more and have less sample capacity and of course they can break if scratched accidently. That means you will generally not be able to measure as low a level as you might need and that capillary may cost you a lot more than the $100 or so required for a packed column.

Since hydrogen may very well be an impurity in helium you will not be able to see a hydrogen impurity if you use hydrogen carrier.

My company (a competitor to Restek) also sells a megabore plot 5A sieve column and I could have recommended it, but the best straightforward, low cost solution would still be a 5A or a 13X packed molecular sieve column. You can connect to capillary injector/detector with simple unions and pieces of almost any FSOT tubing from an old column if you don't have a packed column injector/detector connections.

How much money do you have to spend and how many samples do you have to test, and at what levels do you want to measure?

These are important questions that need to be answered before you decide on your best solution.

If all you have to measure is He and O2 (no other contaminants) then any porous polymer column with H2 or Ar carrier will work as well.

If you use helium carrier then you will only see Helium impurities and not the balance Helium peak. That might be a technique for a TCD you might want to consider, but especially if you have access to a He Ionization Detector from Valco or Gowmac which will measure extremely low levels of contamination.