Quantitative NMR Studies of Multiple Compound Mixtures

Abstract

The unique analytical capabilities of both identification and quantification of compounds in complex mixture by NMR technique have been demonstrated. qNMR is widely applied as routine analytical tool for the mixtures because of the universal existence of NMR-active nuclei. qNMR is one of the few standard-free quantification methods. It can quantitatively analyze multiple compound mixtures without requirement of chemical identical standards. In this review, theoretic background and technical keynotes on qNMR data acquisition, spectral processing, and signal deconvolution/integration will be discussed for quantitative analysis of multiple compound mixtures. Sample preparation and the effect of different sample conditions on the assessment of the concentration will also be discussed. 1H 1D qNMR is the most often used method for quantitative analysis of multiple compound mixtures, yet heteronuclear 1D and 2D qNMR approaches have been increasingly recognized and exploited for quantitative assessment or concentration measurement. Some often used quantitative NMR methods are then summarized. Afterwards, applications of qNMR in the areas of metabolomics, natural products, traditional Chinese herbal medicine (TCM), pharmaceutical research and food analysis are exemplified. Finally, we prospect the future developments and applications of qNMR.