Isotope fractionation

Isotopic fractionation can be measured by isotope analysis, using isotope-ratio mass spectrometry or cavity ring-down spectroscopy to measure ratios of isotopes, an important tool to understand geochemical and biological systems.

For example, biochemical processes cause changes in ratios of stable carbon isotopes incorporated into biomass.

Values for alpha tend to be very close to 1.

Isotope fractionation occurs during a phase transition, when the ratio of light to heavy isotopes in the involved molecules changes.

When water vapor condenses (an equilibrium fractionation), the heavier water isotopes (18O and 2H) become enriched in the liquid phase while the lighter isotopes (16O and 1H) tend toward the vapor phase.