A NEW CRITERION FOR AUTOMATIC PHASE CORRECTION OF HIGH-RESOLUTION NMR-SPECTRA WHICH DOES NOT REQUIRE ISOLATED OR SYMMETRICAL LINES

A new method called ZOE (zero-order equality) for automatic phase corr ection of routine FT-NMR spectra is proposed. Starting from the notion that the ratio between the integrals of a peak in the imaginary and i n the real part of the spectrum is correlated to the phase of the peak , a function is constructed which goes to zero when the spectrum does not need first- or higher-order corrections. The root of this function can be rapidly found by iteration and furnishes the value for first-o rder phase correction. Also, an ancillary very fast peak-finding algor ithm is proposed which is insensitive to phase distortions. Experiment al results show that ZOE succeeds when other methods cannot be applied , the main requirements being a fair baseline and S/N ratio, which are often fulfilled in routine high-resolution H-1 NMR (and not, for exam ple, in the field of in vivo spectroscopy). Other requirements, such a s phase errors of less than second order and phase differences within the peaks not greater than pi, are usually met in high-resolution spec troscopy. (C) 1994 Academic Press,Inc.