The Collaborative International Dictionary of English v.0.48:

Tritiated \Trit"i*at*ed\ (tr[i^]t"[i^]*[=a]t*[e^]d), a. (Chem.)
   containing tritium; -- of chemical compounds; as, tritiated
   thymine.

   Note: Compounds which are tritiated are, as a consequence,
         radioactive, and may be used as tracers in biochemical
         or chemical analysis.
         [PJC]