Marilyn,

I can't comment on the heating settings, but I can on the preconditioning.

At 1400C, the alumina isn't as unreactive as you might hope. Putting 
a conditioning injection through will coat the inner surface with a 
thin layer of carbon that will act as a barrier (much like the glassy 
carbon tube in the TC/EA).

It's a bit of an art getting it just right. Load too much carbon and 
that will cause problems too. Also, it's possible to gas deposit a 
thick carbon tube on the inside of the alumina that can eventually 
block the gas flow. Ultimately, run lots of standards so that you 
will know if it is working correctly (as if you wouldn't do that 
already!!!!).

Paul Eby
University of Victoria

At 08:09 AM 09/01/2009, you wrote:
>Dear Isotopers,
>
>We're turning on our high temperature GC pyrolysis furnace for the 
>first time. I can't seem to find clear/straightforward instructions 
>in either manual that I have access to at the moment. [Is the Pope Catholic?]
>
>Can someone recommend the timing and rate and temperatures for this 
>reactor furnace?
>
>Also, one manual mentions preconditioning, meaning injecting a 
>microliter of solvent in the column before actually analyzing 
>samples. Does anyone know what this actually does? And, do any of 
>you have a procedure in place for this?
>
>Thanks for your help. We're proceeding and will keep you informed regardless.
>
>Marilyn Fogel
>
>
>
>Dr. Marilyn L. Fogel
>
>Geophysical Laboratory
>
>Carnegie Institution of Washington
>
>5251 Broad Branch Rd., NW
>
>Washington, DC 20015
>
>Phone (202) 478-8981
>
>Main office (202) 478-8900
>
>FAX (202) 478-8901
>
>Website: <http://fogel.gl.ciw.edu/>http://fogel.gl.ciw.edu/
>
>
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