https://doi.org/10.1351/goldbook.I03346
A molecular ion containing one or more of the less abundant naturally occurring @I03331@ of the atoms that make up the molecular structure. Thus, for ethyl bromide there exist isotopic molecular ions such as: 13CCH5Br+·, C2H4DBr+·, C2H581Br+·, 13C2H581Br+·, etc.