A magnificent aspect of contemporary NMR spectrometers is that their data is intrinsically quantitative. By adhering to several experimental guidelines, they ensure that good accuracy and precision are possible to attain on a routine basis.
Quantification by NMR is mostly accomplished using protons; in principle, many spin ½ nuclei may be used as well. A distinct quantification characteristic when using NMR is that usually, no chemistry is required up front on the molecule, and response factors are not required to be cataloged. It is possible to simply add the analyte to a solution and record the outcome. Thus, qNMR is a non-destructive analytical approach.
Quantitative analysis with qNMR data depends on the precision required for an answer. Experimental details are also more crucial, as more sub-percent accuracy is needed. If an accuracy of just a few percent is adequate for the problem faced, little is required apart from a routine spectrum and a result from a similar sample of known concentration, which acts as an external reference.
Many software instruments exist to provide results for traditional integration or direct time-domain amplitude extraction, including CRAFT, which practically removes operator bias and skill from the all-important data analysis section or the qNMR process.
About the Presenter
Presenter: Ron Crouch, NMR in Applications
After earning his degree from Elon University, Ron Crouch began his career at Burroughs Welcome Pharmaceuticals, where he worked alongside Nobel Prize winner Gertrude Elion and many other esteemed scientists. His final nine years at Welcome were further enriched by the opportunity to collaborate directly with Gary Martin.
Ron eventually left the pharmaceutical industry to pursue his passion for NMR more intensively, taking on the role of R&D Manager at Nalorac Corp. He then spent several years with Varian NMR in Applications until Agilent exited the NMR field. Since joining JEOL USA, Ron has thoroughly enjoyed continuing his NMR work and expanding his expertise in the field.