NMR Spectroscopy is Quantitative. No Adjectives Required

Abstract

Why is that more than half a century has passed since the commercialization of NMR spectrometers, and this still needs to be stated? Well, perhaps the field is a victim of its own successes. The emphasis of NMR research and development has focused on deciphering intricate structural information– an important function, no question. This has been supported by the increased magnetic field strength (up to 1.3 GHz at the time of this writing!), enhanced sensitivity (cryoprobes, hyperpolarization) and sophisticated pulse sequences (ultrafast, anisotropy, nD) that help eke out fundamental structural information for increasingly complex molecules at ever decreasing concentrations. These efforts have expanded the boundaries of NMR spectroscopy in an undoubtedly elegant manner– for research. While certainly solidifying the reputation of NMR as being the most information rich spectroscopic technique, it has also inadvertently hindered its wider adoption by the end user, by application, and by sector. It just may be that expanding the structural elucidation toolbox has come at the expense of the other unique aspect of NMR– its inherently quantitative nature. In fact, when this facet is discussed, it is dubbed ‘qNMR’ as though it is not intrinsic to the technique itself.

So, what are the obstacles hindering the widespread adoption of ‘qNMR’? As we see it, the answer is three-fold: (i) accessibility, (ii) the lack of NMR-based quality control methods, and (iii) public perception.