Římal, Václav, Morgane Callon, Alexander A. Malär, Riccardo Cadalbert, Anahit Torosyan, Thomas Wiegand, Matthias Ernst, Anja Böckmann, and Beat H. Meier. “Correction of Field Instabilities in Biomolecular Solid-State NMR by Simultaneous Acquisition of a Frequency Reference.” Magnetic Resonance 3, no. 1 (February 9, 2022): 15–26.
https://doi.org/10.5194/mr-3-15-2022.
With the advent of faster magic-angle spinning (MAS) and higher magnetic fields, the resolution of biomolecular solid-state nuclear magnetic resonance (NMR) spectra has been continuously increasing. As a direct consequence, the always narrower spectral lines, especially in proton-detected spectroscopy, are also becoming more sensitive to temporal instabilities of the magnetic field in the sample volume. Field drifts in the order of tenths of parts per million occur after probe insertion or temperature change, during cryogen refill, or are intrinsic to the superconducting high-field magnets, particularly in the months after charging.