A modern NMR spectrometer has the exquisite property that the data is inherently quantitative. By following a few experimental guidelines, good accuracy and precision are routinely obtainable. Though quantification by NMR is most commonly done using proton, in principal many spin ½ nuclei could also be used. A unique aspect of quantification using NMR is that typically no chemistry needs to be done up front on the molecule and response factors do not need to be cataloged – Simply put the analyte into solution and record the results. Therefore, qNMR is a non-destructive analytical technique.
The approach to quantitative analysis with qNMR data depends upon how precise an answer is needed. Experimental details also become more critical as higher sub-percent accuracy is required. If an accuracy of a few percent are sufficient for the problem at hand not much is needed except a routine spectrum and a result from a similar sample of know concentration as an external reference. There are many software tools to allow results for either traditional integration or direct time-domain amplitude extraction such as CRAFT which virtually eliminate operator bias or skill from the all-important data analysis part or the qNMR process.
Presenter: Ron Crouch, NMR in Applications
After obtaining his degree from Elon University Ron joined Burroughs Welcome Pharmaceuticals where he had the great pleasure to work with Noble Prize winner Gertrude Elion and many other world-class scientists. The last 9 years at Welcome were further enhanced by having the joy of working directly with Gary Martin.
He left the pharmaceutical industry to more deeply pursue his love for NMR as R&D Manager with Nalorac Corp followed by many years with Varian NMR in Applications until the demise of Agilent NMR. Since then he has been having great fun with JEOL USA continuing to pursue NMR and learn in a very in-depth manner.