New insights into diffusive kinetic fractionation during liquid condensation under supersaturated environment: an alternative approach for isotope tagging of ground-level water vapour.

Stable water isotopes in ground-level vapour are key to estimating water exchange between geospheres. Their sampling, however, is limited to laser-absorption spectrometers and satellite observations, having inherent shortcomings. This study investigates diffusive kinetic fractionation during liquid condensation under supersaturated environment, providing a cost-effective, reliable way of sampling ground-level vapour isotopes (O, H).

application of carbonic anhydrase to accelerate the equilibration of O between HO and CO for the rapid measurement of O/O isotope ratios in aqueous samples.

A novel method of the accelerated equilibration of O between CO and HO for the measurement of the O/O isotope ratios in aqueous samples with natural isotope abundances is presented. This rapid equilibrium method is based on the application of the enzyme carbonic anhydrase (CA). The CA from bovine erythrocytes was adsorptively fixed to 3-mm glass beads with an etched surface.