13C solid-state NMR chromatography by magic angle spinning 1H T1 relaxation ordered spectroscopy

An efficient method to separate the 13C NMR spectra of solid mixtures is introduced. The 1H longitudinal (T1) relaxation time is used to separate the overlapping 13C chemical shift spectra of solid mixtures via an inverse Laplace transform (ILT) of the relaxation dimension. The resulting 2D spectrum of the mixture contains separate 13C spectra for each component of the mixture that are identical to 13C spectra of the isolated materials. The separation is based on the equalization of 1H T1 values in a single domain by rapid 1H spin diffusion and on the 1H T1 value differences between different domains. The introduction of a general ILT scheme enables efficient and reduced data acquisition time. The method is demonstrated on a mixture of two disaccharides and on a commercial drug containing several compounds.