Data-processing routines for automated relaxation times and nuclear Overhauser effect measurements on a FT NMR spectrometer

Introduction The value of measuring such nuclear magnetic resonance parameters as longitudinal and transverse relaxation times, and nuclear Overhauser effect enhancement factors has already been demonstrated [1]. While most modern Fourier Transform (FT) NMR spectrometers are fitted with the appropriate pulse sequence capabilities, they generally only provide a linear semi-10garithmic least-squares fit routine, which is insufficient for obtaining reliable relaxation time values [2-7]. Therefore, routines for a Jeol PFT 100 NMR spectrometer have been developed in this laboratory in order to compute on-line relaxation times using a two and threeparameter non-linear least-squares fit for most T1 (IRFT, FIRFT, SRFT, Freeman-Hill modified IRFT) [8] and T2 (CPMG) [9] measurement pulse sequences. A further routine increasing the reliability of NOE enhancement factor measurement 10, 11 from line areas in connection with phase correction has also been added. The basic principles involved and the algorithms of these routines are described here.