SOLVENT ELIMINATION FROM H-1-NMR SPECTRA - TUNABLE NOTCH FILTER

The construction and operation of a tunable-frequency, tunable-width band-reject active filter for selective suppression of a strong solvent NMR signal which is not too close in frequency to a weak solute peak is described. In comparison to other available techniques for achieving comparable (≥ 20-fold) reduction in solvent peak height, with corresponding increase in spectral dynamic range, the notch filter has the following advantages: (a) Suppression is equaly effective for HDO or H2O without further adjustments; (b) suppression is equally applicable to continuous-wave or pulsed Fourier transform detection; and (c) no additional double-irradiation, software, or special pulse gating is required. © 1979.