A method for longitudinal relaxation time measurement in inhomogeneous fields

NMR Relaxation Measurements on Complex Samples Based on Real-Time Pure Shift Techniques

“…Although signal evolutions during inversion recovery delay in IR experiments for T 1 measurements and spin-echo delay in CPMG experiments for T 2 measurements are free of field inhomogeneity, the acquisition periods in these two relaxation experiments cannot avoid the field inhomogeneity effect, thus giving rise to spectral line broadenings in acquired 1D NMR spectra and hindering accurate relaxation measurements. Recently, a relaxation method based on the combination of intermolecular double-quantum coherence (iDQC) [23] and IR scheme was proposed to achieve T 1 relaxation measurements in inhomogeneous magnetic fields, in which the iDQC scheme is used for eliminating field inhomogeneity and the IR scheme serves for T 1 relaxation evolution [24]. However, J coupling splittings still exist and acquired 1D T 1 evolved spectra are presented in absolute-value mode, thus influencing accurate T 1 relaxation calculation.…”