Dear all,

Many thanks to everyone who replied to my previous queries.

I would like to know what grade of CO2 people use when equilibrating waters
for subsequent delta 18O analysis on a mass spec. I assume that the purer
the CO2 the better as impurities have the potential to be a source of
contamination? The system is currently running with Scientific grade but is
this necessary? Will UHP CO2 be just as good?

Also, what are people using as reference gas? Is this the same CO2 as used
for the equilibration or something different, say gas of a special or
specific composition? This is for both waters and carbonates.

Many thanks in advance,
Karen


Dr Karen Leslie
Earth Sciences
University of Queensland
St. Lucia, Qld, 4072
Australia
E-mail: [log in to unmask]
www.earth.uq.edu.au
Tel:    +61 7 336 51132 / 53281