Abstract: The rare earth in its mixture has been determined by ¹H and ¹³C NMR in its aqueous halide solution. For samples containing only light lanthanides,both ¹H and ¹³C spectrometry can be used for quantitative determination of individual rare earth in the mixture. For samples containing heavy lanthanides, ¹H spectraometry is unsuitable for accurate determination due to the serious broadening and overlapping of the signals in the spectra and interference from water. ¹³C spectrometry,however,can be used successfully since each complex of Ln (NTA)₂ in the mixture has at least a unique well-re-solved peak.

Key words: rare earth, nitrilotriacetate, complex, determination, NMR