O2 and Ar Separation at ambient temperature

[kan]

Normally sub-ambient cooling is needed for O2 and Ar separation(using TCD detector, molecular sieve column).

Any work done before at ambient temperature? Please specify the configuration and condition.

Do explain the reason behind if it cannot be done.

Tx.

[chromatographer1]

Topic: O2 analysis in Nitrogen

Posted: Mon Apr 21, 2008 9:28 pm

Yes it is possible. The separation pictured in the chromatogram was performed on a 9 meter 1/8" OD column packed with a special preparation of molecular sieve 5A. Temperatures were slightly above ambient, 27°C (80°F). Common MS5A will not perform this separation unless the oven temperature is dropped below ambient.

This packing is only available through Supelco. You may contact me directly if you are interested.

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

[mbicking]

A 30 m mol sieve column will produce an adequate separation of Ar and O2 at 30 - 35 C. If you can start at lower temperatures, the separation will be better.

There are several packed column options also, most using molecular sieves. Alltech sells a combination column that claims to be able to do this separation. I believe the column names are CTR-1 and -3.

[GasMan]

You need to stipulate the concentrations of the Argon and Oxygen. From my experience, the above columns are OK with low concentrations of Ar, such as in air. However, if you are trying to measure low concentrations of oxygen in argon you will not be successful at room temperature.

Gasman

[CE Instruments]

Buy an Argon Ionisation detector from Orthodyne (Belgium) and analyse ppb impurities including O2/N2 in pure Argon