ISOGEOCHEMISTS,

The research that I am involved in requires the use of both  C and O
enriched isotopes in the same tracer studies and I need to be sure
that I can correctly attribute values to 13C/12C and 18O/16O in CO2.
Manufacturers suggest that their instruments can do this by using the
mz 46/44 ratio. However when both C and O of CO2 are enriched this is
not always possible as the Craig 18O correction is designed for
near-natural abundance levels. Any ideas?

nick




                     Nick Ostle
      Institute of Terrestrial Ecology
                ITE- Merlewood
             Grange-Over-Sands
              Cumbria, LA11 6JU
                     England

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