Since the inception of NMR, the field has been marked by rapid change and frequent innovations as evidenced by Nobel Prizes in physics, chemistry and medicine:
1943 – Stern – discovery of magnetic moment of a proton
1944 – Rabi – resonance method for recording magnetic properties
1952 – Bloch & Purcell – new NMR measurements
1991 – Ernst – high-resolution NMR
2002 – Wuthrich – determining 3D structure of biological macromolecules
2003 – Lauterbur & Mansfield – discoveries in MRI
Prior to 1961, NMR spectrometers were not commercially available. They were made in specialized physics laboratories and operated exclusively by trained experts. These spectrometers generated an external magnetic field with permanent iron magnets. This technology was found to have a theoretical limit of about 100 MHz, and therefore was soon made obsolete in favour of super-conducting technology.
Why? Higher field = greater resolution (now ranging up to 1000 MHz!!) = improved structural elucidation. Regardless of these undeniable benefits, there are some downfalls to HR spectrometers – namely high cost and major steric restrictions. These spectrometers require dedicated, controlled locations and trained maintenance staff to perform weekly cryogen fills. As such, despite the benefits that NMR could add to industrial, online applications, the ubiquitous technique remains largely underrepresented in industry.