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Chemistry 19-020

Carbonic anhydrase-catalyzed isotope equilibrium for oxygen isotope analyses of aqueous samples


An image of a variety of flasks and vessels with liquid in them.
This patent pending method reduces oxygen isotope equilibrium reaction time from 24H to less than 1 h.

Tech ID



S. Kim
N. Randazzo
M. Knyf

Patent Status

US patent pending
CA patent filed

Stage of Research

Experimentally verified
Data is available upon request


Glen Crossley
Associate Director
Business Development and Intellectual Property


Oxygen isotope studies of aqueous samples are typically determined through the isotopic equilibration of CO2 gas and H2O.This equilibration process typically takes 24 hours in a closed undisturbed reaction vessel, limiting laboratory throughput.

The technique developed at McMaster utilizes carbonic anhydrase (CA) to rapidly catalyze the oxygen isotope exchange reaction, bringing the reaction time from 24 hours to less than one hour. This technique is compatible with commercially available CO2-H2O equilibration devices, and can be easily and immediately adopted by any laboratories that measure the oxygen isotope compositions of aqueous samples.


Oxygen Isotope analyses in fields such as:

  • Environmental sciences: Geology, Hydrology
  • Carbonate isotope analyses
  • Biology
  • Medical


  • Reduce equilibrium reaction time from 24h to<1h.
  • Increase laboratory throughput capability.
  • Compatible with existing commercially available equipment.

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