Hi Joy,


What kind of capsules do you use for sample introduction? Does you reactor
packing contain a crucible or similar contraption to collect capsule
"residue"? Also, at which temperature do you run your reactor?

Your peak shape might suffer as a result of "ash" (read; silver granules
should you be using silver capsules) build-up at the bottom of the reactor,
which disturbs the carrier gas flow and, hence leads to peak broadening

Re glassy carbon chips, we got straight from the horse's mouth as it were
(HTW GmbH, Thierhaupten, Germany).

Yes, it is possible to "refurbish" the chips. Rub them between fine emerald
paper and then wash them with dd water a couple of time.


Cheers,

Wolfram



> -----Original Message-----
> From: Stable Isotope Geochemistry
> [mailto:[log in to unmask]] On Behalf Of Joy Davis
> Sent: 01 June 2005 21:18
> To: [log in to unmask]
> Subject: Reuse of glassy carbon grit
>
>
> We are beginning to run 18-O on solid organics by pyrolysis
> to CO.  The (ceramic) pyrolysis column is packed with glassy
> carbon grit with ~10% nickelized carbon.  After about 150
> samples, the peak shape deteriorates and the signal drops.
> The column packing appears (visually) unchanged from the
> initial packing.  Can the glassy carbon be
> regenerated/cleaned and reused?
>
> Also, Alfa Aesar has two "types" of glassy carbon that differ
> primarily in their "maximum service temperature".  We (by
> mistake) are currently using the lower temperature glassy
> carbon (1100C).  What does maximum service temperature
> specify and what kind of change in behavior am I likely to
> see with the higher temperature (3000C) grit?
>
> Thanks.
> - Joy Davis
> Old Dominion University
> Norfolk, VA, USA
>