Separation of components of a 1H NMR composite signal by nutation experiments under low amplitude radio-frequency fields. Application to the water signal in clays

It is shown theoretically and experimentally that, times under weak radio-frequency field conditions, the nutation frequency depends on relaxation. The Fourier transform of the nutation curve yields separate bands corresponding to the components of an unresolved composite signal. This can be effectively achieved, provided that these components possess different relaxation characteristics.