I would repack the combustion tube. It could be that the catalyst is going,
but not enough to affect easily combusted materials.
University of Michigan
School of Natural Resources & Environment
Dana Building, Room G540
430 East University
Ann Arbor, MI 48109-1115
--On Wednesday, May 07, 2003 10:59 AM -0400 "Carl G. Johnson"
<[log in to unmask]> wrote:
> We only infrequently run EA-IRMS, and are having problems getting back
> to operational mode.
> Basically, we can get acceptable accuracies and precisions on a number
> of volatile and easy to burn materials (hydrocarbons and steranes), but
> can not get good numbers on less volatile materials (sucrose and
> limestone). We interpret this as a burn problem, but don't know what
> parameters to tweek.
> We are using a CE 1108 EA, sealed head carousel, tungsten oxide and
> copper beds. We have made sure that we have good flow, the drop time
> corresponds to a second or two before the maximum burn time for a boat
> previously dropped without oxygen. We apparently get a good burn
> (visually). The system is leak tight and the volatiles give good data.
> Any ideas?
> Carl Johnson
> Woods Hole Oceanographic Institution
> [log in to unmask]