Methods for peak assignment in low-resolution multidimensional NMR cross-correlation relaxometry

Several NMR protocols are presented for assigning peaks in complex T1-T2 spectra, including the effects of varying the spectrometer frequency and the CPMG pulsing rate. Extensions into a third dimension based on chemical-shift; diffusion- and field-cycled weighted T1-T2 cross-correlation methods are also explored as a means of peak assignment. We illustrate the power of these novel techniques with reference to simple aqueous sucrose solutions, but the methodology should be generally applicable.