A method of characterizing chemical and/or morphological features of a material, comprising acquiring energy relaxation data from 1H low field nuclear magnetic resonance (1H LF-NMR) measurements of said material, converting the relaxation signals into a multidimensional distribution of longitudinal and transverse relaxation times by solving an inverse problem under both L1 and L2 regularizations and further imposing a non-negativity constraint, and identifying one or more characteristics of said material with the aid of said multidimensional T1-T2 distribution. The method is useful, inter alia, in monitoring chemical processes, screening of additives and quality control.