Dear all,
        This is my virginal posting so excuse any failures in
protocol.  In response to Steve Nelson's posting I thought this
might be of use.  I use triple distilled water (is this ultra
pure?) with other media added to culture bacteria on certain
target contaminants.  I have added known concentrations of CO2
to the headspace of a closed system and studied CO2 eqilibration
by analysing the fractionation of the Delta 13C value left in
the headspace as a function of time. Accounting for temperatures
from 4C to 35C and headspace concentrations of 1% to 10%
equilibration is complete within 60 minutes.
                I hope this helps,
                                        James Hall
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James Hall
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