Improved method for pulse width calibration in indirectly detected experiments

A new sequence for calibrating the pulse width in indirectly detected experiments is described. It uses a field gradient pulse to destroy the transverse magnetization from nuclei that are not coupled to the indirectly detected species. With low natural abundance heteronuclei such as ²³C or ¹⁵N, the latter component is responsible for a very intense resonance, with large dispersive tails, that hinder the observation of the intensities of the satellite peaks, especially at the null point. The proposed sequence improves the accuracy of the calibration owing to the excellent suppression of the unwanted dispersive signals. We named the sequence ROSSANA, i.e. Rotating Satellite Selective Acquisition at Natural .Abundance.