Hello Everyone,

I have a problem with the Carlo Erba NA-1500 elemental analyzer that
is attached to our Isoprime mass spectrometer.  The combustion of
samples appears to be incomplete.  As a result the precision is very
bad and when we run empty tin cups we observe a very high background.
The high background problem disappears if I put in a new reaction
column, but reappears after about 50 samples.   I can obtain
consistent results for my standards if I run an empty tin cup between
each, but this is not an acceptable solution.  As far as I can tell
the combustion temperature is OK (1020 °C according to the readout)
and none of the parameters (i.e., sample drop time, oxygen flow etc.)
have been changed.  Is it possible that the furnace for the reaction
column is dying?

I would appreciate any suggestions regarding how I might solve this problem.

Yours truly,
Jennifer.

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Jennifer Mckay
Agente de Recherche / Research Associate
GEOTOP - Universite du Quebec a Montreal
C.P. 8888, succursale Centre-Ville
Montreal, Quebec, Canada
H3C 3P8

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