Dear Rolf,

My request for specifications crossed your specification message it
seems.
Thanks for the info - it is usefull.
Still I have my reserves about the salted water, not because the water
component will not be analysed correctly, but because of the salt
deposition just after injection, with all problems known for htat
process - as I brought forward before: hydrated salts and, if that
problem is solved by heating, the pollution by the salt deposits and
evt. in more extreme cases attack (if heated) of the glass.
This should be tested by dissolving salts in waters with known
isotopic composition and analysis by the Cr reduction method. I expect
similar problems as, for instance, in case of U reduction method -
with deposition of salts in injection places.
Destillation of salted water might be a solution here, followed by
H-isotope analyses of the 'clean' waters - but always this has risk of
fractionation if not handle carefully - and it is a time-consuming
procedure too.

Another matter you brought forward, and I am curious about, is the
'clean silica glass' preparation. Which preparations you exactly mean
here - just working in a 'clean way' by the glassblower = not getting
grease or other contamination on the glass while working - or do you
mean other precautions/procedures?

Pier.
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Dr. P.A. de Groot
University of the Witwatersrand
Economic Geology Research Unit
Department of Geology
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South Africa
Tel.    +27 11 7162564
Fax.    +27 11 3391697
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