I believe Nafion traps are fairly robust and don't "break down". Certainly material could flow through them that would degrade them. If you suspect the ability for it to remove water, you might try lightly heating it while helium is flowing...you will typically get a fair bit of water off. Perhaps you had a wet helium cylinder? Are you detecting a leak? I have had bad luck with the base of the sample open split that seems to begin leaking after thousands of samples. 

andy


 Andrew Schauer
ISOLAB
Department of Earth and Space Sciences
University of Washington
Seattle, WA 98195


206.543.6327
[log in to unmask]


----- Original Message ----
From: Joe Lambert <[log in to unmask]>
To: [log in to unmask]
Sent: Monday, June 16, 2008 7:21:24 AM
Subject: [ISOGEOCHEM] Gasbench Nafion Traps

Hi everyone,

      I was hoping to get some advice regarding the two Nafion water traps
in Thermo's Gasbench.  Can anyone please explain the symptoms of a Nafion
trap that is no longer functional?  I'm assuming the trap directly after the
sample needle is typically the first to go.  Is there a way to test which
trap has the problem?  Finally, what is the expected life of Nafion traps? 
We've had about 7,000 samples through the machine with only a few hundred
being water samples.

Thanks in advance,

Joe Lambert
Alabama Stable Isotope Laboratory