REFERENCE DECONVOLUTION, PHASE CORRECTION, AND LINE LISTING OF NMR-SPECTRA BY THE 1D FILTER DIAGONALIZATION METHOD

We describe a new way to attack the problem of identifying and quantif ying the number of NMR transitions in a given NMR spectrum. The goal i s to reduce the spectrum to a tabular line list of peak positions, wid ths, amplitudes, and phases, and to have this line list be of high fid elity. In this context ''high fidelity'' means that each true NMR tran sition is represented by a single entry, with no spurious entries and no missed peaks. A high fidelity line list allows the measurement of c hemical shifts and coupling constants with good accuracy and precision and is the ultimate in data compression. There are two parts to the p roblem. The first is to overcome common imperfections: the non-Lorentz ian lineshapes that can arise whenever the magnetic field inhomogeneit y is less than perfect, and nonzero time delays that cause frequency-d ependent phase errors. The second is to fit the spectral features to a model of Lorentzian lines. We use the recently developed filter diago nalization method (FDM) to accomplish the reference deconvolution, the phase correction, and the fitting, and show good progress toward the goal of obtaining a high fidelity line list. (C) 1998 Academic Press.