Improved method for pulse width calibration in indirectly detected experiments

A new sequence for calibrating the pulse width in indirectly detected exper iments is described. It uses a field gradient pulse to destroy the transver se magnetization from nuclei that are not coupled to the indirectly detecte d species. With low natural abundance heteronuclei such as C-13 or N-15, th e latter component is responsible for a very intense resonance, with large dispersive tails, that hinder the observation of the intensities of the sat ellite peaks, especially at the null point. The proposed sequence improves the accuracy of the calibration owing to the excellent suppression of the u nwanted dispersive signals. We named the sequence ROSSANA, i.e. ROtating Sa tellite Selective Acquisition at Natural Abundance. Copyright (C) 2001 John Wiley & Sons, Ltd.