Abstract: Determination of the assignment and relative intensity of tritium in the fire specific labelling compounds (dihydro-Alprenolol. Abendazol. Etorphine. pyronaridine and cholor promazine)and General labelling selagine using ³H-NMR spectrometry is described. In addition, The triton-proton coupling codnstants(J_HT)-were measured by the ³H-NMR spectra of Cmethyl-³H] Thymifine and[4-³H] phenylalanine without decoupling. The "magnetically-equivalent" proton-proton coupling constants can be calculated from J_HT Values.