Diffusion-ordered spectroscopy (DOSY) is a valuable tool for the analysis of intact mixtures, since it can separate the signals of components according to their apparent diffusion coefficients. However, DOSY experiments are acutely sensitive to spectral quality, and especially to signal overlap, which can lead to misleading apparent diffusion coefficients. Oneshot-iDISPEL reduces signal overlap in mixtures with a wide range of concentrations, by removing one-bond 13C satellites. In such high dynamic range mixtures, 13C isotopomer signals from major components can overlap with signals from minor components, causing problematic distortions in the diffusion domain of a DOSY spectrum.

Pulse sequence diagram:

The new method, Oneshot-iDISPEL, is a combination of the Oneshot and DISPEL experiments. Oneshot sequence uses a stimulated echo and unbalanced pairs of bipolar gradient pulses for diffusion measurements. Here, the Oneshot pulse sequence is expanded to accommodate DISPEL for the suppression of 13C satellite signals.

Pulse sequence:
oneshot_iDISPEL_b (right click and chose 'save ... as')

Moutzouri, P.; Kiraly, P.; Foroozandeh, M.; Phillips, A. R.; Coombes, S. R.; Nilsson, M.; Morris, G. A.; J. Magn. Reson. 295, 6-11, 2018.
DOI: 10.1016/j.jmr.2018.07.011