Dear Ian and others,
we are experiencing similiar problems on a laser
fluorination line using F2 as reagent. Beside the  freezing
problem described, we found an d18O shift that correlates
very well with the amount of intefering masses on mass 69.
Obviously, some flourine gas passes through no matter what
we are doing with the KBr trap (changing trapping time,
changing grain size of the KBr etc.). So, we too are very
interest in any suggestion how to get rid of by-passing
flourine. Especially as we would not like to switch over to
BrF5.
greetings
Stefan

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Dr. Stefan Krumm                                 Institut
fuer Geologie
Schlossgarten 5                                  Tel.: ++49
9131 856063
91054 Erlangen, Germany                          Fax.: ++49
9131 859295
e-mail: [log in to unmask]

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