(1)H relaxation times of metabolites in biological samples obtained with nondestructive ex-vivo slow-MAS NMR.

Methods suitable for measuring (1)H relaxation times such as T(1), T(2) and T(1rho) of metabolites in small, intact biological objects including live cells, excised organs and tissues, oil seeds etc. are developed in this work. This was achieved by combining inversion-recovery, spin-echo, or a spin-lock segment with the phase-adjusted spinning sideband (PASS) technique, which was applied at low sample-spinning rates. Here, PASS was used to produce high-resolution (1)H spectra in a nondestructive way so that the relaxation parameters of individual metabolite could be determined. The methodologies were demonstrated by measuring (1)H T(1), T(2), and T(1rho) of metabolites in excised rat liver at a spinning rate of 40 Hz.