Hello Everyone,

I have a problem with my mass spectrometer - EA system.  When we run
empty tin cups we are getting a higher than normal background for
beam 44 (6 to 9 E-10).  I've tried different batches, sizes and types
of tin cups and still the same problem.  Interestingly, when we run
real blanks (i.e., no tin cup is dropped, but everything else remains
the same) we don't see the high background.  This leads me to believe
that the tin cups are contaminated.  Has anyone else noticed a
problem with the tin cups supplied by Elemental Microanalysis Limited
beginning in December 2002?  Can anyone think of what else may be
causing our high background if it is not the cups?  I have changed
the gases (O and H) and the He purifier, heated the GC column to give
it a cleaning, changed the combustion column using both pre-packed
columns and columns we packed but still the problem persists.  I've
checked for leaks on both the EA and mass spec and even cleaned the
source.

Any help would be greatly appreciated.

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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