The difference between the deuterium (D)/hydrogen (H)
→ abundance → ratio
in an object with respect to that representing a standard or mean value for
that type of objects. Same as → isotope fractionation
of deuterium. In the gas phase chemistry many of the D fractionation
reactions produce an excess of D atoms relative to → hydrogen
atoms. Deuterium fractionation in → interstellar cloud
cores, → protostars, and
→ Solar System bodies is frequently used to infer important
aspects of their physical and chemical histories. For example, the
→ deuterium enhancement
in the Earth’s sea water, with respect to the cosmic abundance, has
been interpreted as being due to → enrichment
by → comet-like → planetesimals
colliding with the young Earth.
See also: → deuterium; → fractionation.
