RESOLUTION IMPROVEMENT IN NMR-SPECTRA - APPLICATION AND SIGNIFICANCE OF CHEMICAL-SHIFT UPSCALING IN MULTIDIMENSIONAL NMR EXPERIMENTS

An analysis of resolution in nuclear magnetic resonance (NMR) spectra in terms of separation, linewidth, and limited digitization capability is presented. The effect of scaling up of frequencies on resolution i s considered, and criteria useful for determining whether two peaks ar e resolvable in continuous-wave and digitized spectra are derived. Fin ally, a new pulse sequence based on upscaling of chemical shifts is de scribed for resolution improvement along the F-1 dimension in heteronu clear correlation NMR spectra. The performance of the sequence is demo nstrated by experimental data on large proteins, and simulations are p erformed for its optimization. (C) 1998 John Wiley & Sons. Inc.