specifically labelled
An
isotopically labelled
compound is designated as specifically labelled when a unique
isotopically substituted
compound is formally added to the analogous
isotopically unmodified
compound. In such a case, both position(s) and number of each
labelling
nuclide
are defined.
Source:
Blue Book, p. 514
PAC, 1981,
53
, 1887
(Nomenclature of inorganic chemistry: II.1 - Isotopically modified compounds)
on page 1891