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How select column to analyse O2 and N2 in CF4.
Posted: Mon Mar 16, 2009 3:33 am
by gongchke
How select column to analyse O2 and N2 in CF4.thank.
Posted: Mon Mar 16, 2009 7:57 am
by chromatographer1
You have to determine how much oxygen and nitrogen are in your CF4, or at least choose the lower limit you wish to measure of these trace (?) gases.
It is not as straightforward or as easy as many might think.
It would take too long to go through all the details and the choices involved and the problems involved at different levels.
Talk to Supelco or Alltech or Restek. Get professional help.
best wishes,
Rodney George
consultant
chromatographer1 at aol dot com
Posted: Fri Mar 20, 2009 3:15 am
by tigerk2001
What kind of detector are you using? what level O2 N2 are you measuring?
It would normally be possible using an injection valve with a pre-column and a heartcut valve to get rid of CF4 and a molecular sieve to allow O2 N2 separation.
I would be able to measure from low ppb up to ppm using micro PED detector.
Let me know if you would need more support and I can push to find the right pre-column. Maybe porous polymer but I'm not sure.
Posted: Fri Mar 20, 2009 3:16 am
by tigerk2001
What kind of detector are you using? what level O2 N2 are you measuring?
It would normally be possible using an injection valve with a pre-column and a heartcut valve to get rid of CF4 and a molecular sieve to allow O2 N2 separation.
I would be able to measure from low ppb up to ppm using micro PED detector.
Let me know if you would need more support and I can push to find the right pre-column. Maybe porous polymer but I'm not sure.