SUPPRESSION OF DIAGONAL PEAKS WITH SINGULAR-VALUE DECOMPOSITION

A number of modified two-dimensional NMR pulse sequences have been dev eloped to suppress the diagonal peaks which may introduce severe spect ral distortions, such as t(1)-ridges and large dispersive signals on t he diagonal. However, these modifications increase the minimum number of scans, require more complicated experimental designs, and often dec rease the sensitivity of the experiment. Here we present a post-acquis ition method to remove the undesirable diagonal peaks by using singula r value decomposition based on the observation that the diagonal peaks are larger in amplitude than the off-diagonal peaks. The effectivenes s of the scheme is demonstrated by applying the method to process a ph ase sensitive COSY spectrum of alkyl-cyclohexyleneacetic ester. The me thod can also be used for the removal of the diagonal peaks in NOESY, ROESY, and other correlation spectra. (C) 1998 Academic Press.