EVALUATION OF SIGNAL-PROCESSING METHODS FOR THE QUANTIFICATION OF STRONGLY OVERLAPPING PEAKS IN P-31 NMR-SPECTRA

A time series of 16 P-31 NMR spectra of rat liver perfused with 2,5-anhydro-D-mannitol has been quantitatively analyzed by two types of model function fitting algorithms in the time domain: an iterative least-squares fitting procedure (VARPRO) and a noniterative singular-value-decomposition-based method, combined with minimum-variance preprocessing (MV-HTLS). MV-HTLS, which does not allow the incorporation of prior knowledge, is unreliable for the quantification of overlapping peaks at low signal-to-noise ratio. Although the overall fit is good, i.e., the residue is small, the fitted parameters do not accurately represent the individual components. The incorporation of prior knowledge about the model parameters results in a significant gain in precision of VARPRO. (C) 1994 Academic Press, Inc.