best solution for analysis of pure oxygen on ASU

[LDCCL]

Hi all

We have a GC-DID/FID to analyze the pure O2, and with Molsieve5A columns and DE-OX columns and Hayesep Q columns, of course DE-OX can be regenerated by 5% H2 in Helium, just determine the H2,Ar,N2,CH4,CO,CO2but we have a customer need to know how much C1-C4 low carbon organic gas in it(Eg,C2H2,C3H6,C2H4,C3H8etc) who can tell me the best Pack-columns for seperation and other suggestion for it. and does the sample with pure oxygen influence the FID if we use FID.

Many thanks in advance.

Tim

[chromatographer1]

If you can do a multidimensional analysis using a valve to send the gases through a Hapesep or Porapak Q but diverting the H2-methane through a proprietary Argon Sieve column from Supelco to your DID, and the remainder CO2-C4 gases to your FID with a methanizer, then the oxygen will not affect the FID and you can perform the analysis in a fairly short time with one injection.

My only concern is: Can your DID handle a balance of O2 peak when you measure the trace amounts of the other gases ?

If you use a valve already to inject the gases then all you would have to do is to replace the six port valve with a 10 port valve.

best wishes,

Rodney George
consultant
chromatographer1 at AOL dot com

[larkl]

I'd probably convert the GSV to a dual GSV (6 to 10 port), then you can inject the sample on both sides at once (FID for HC, DID for others)

[tigerk2001]

Porous polymer like Hayesep D or Poropak Q would work for C1 to C4 with FID without getting affected by O2. Alumina packed column could also work.
If you work at ppm level, you won't get affected by O2.

For the permanent gases, I'm wondering how you can get rid of the O2 interference with a simple injection. Do you use any O2 getter for argon separation from O2?
I work with micro PED for 10 years and I have configured numerous systems for H2-Ar-N2-CH4-CO-CO2 in O2 from low ppb level up to high ppm level.
Let me know if you need more support, I could be a source of help for you. I don't use O2 copper getter for Ar and O2 separation. I use synthetic zeolite column threated with sodium which allow Ar-O2 separation and the PED can easily detect 1 ppb argon.