When the abundance of a particular
nuclide is increased above the level at which it occurs in nature and is incorporated in
a molecule, the term '
isotopically enriched ion' is used to describe any ion enriched in the isotope.
Source:
PAC, 1991, 63, 1541
(Recommendations for nomenclature and symbolism for mass spectroscopy (including an
appendix of terms used in vacuum technology). (Recommendations 1991))
on page 1549