In the period of 2020 to 2022, the spectrometers in the Josef Dadok National NMR Centre are undergoing thorough upgrades. In late 2020, the electronics of the instruments was replaced by the latest Bruker technology AVANCE NEO. The only difference visible from the outside is that the electronics cabinets are now smaller, half the previous size. This is mainly due to the use of novel wide-band amplifiers, thus eliminating the need for separate high-band and low-band amplifiers. From the functionality point of view, there are improvements in flexibility and stability. The AVANCE NEO is based on a ‘transceive’ principle, meaning each NMR channel has both transmit and receive capabilities. This allows simultaneous acquisition of signals from different nuclei allowing in some cases more efficient data acquisition and opening another way for the development of new methods. Improvements in the frequency generation circuitry, better signal shielding and filtering in the preamplifiers, and faster digital processing in the lock channel improve both inherent stability and resistance to the external disturbances. The stability is essential in NMR spectroscopy as we need to measure tiny differences of the resonance frequencies of the order 10-8 to achieve high resolution. We have already observed decreased level of the so called t1-noise in the spectra which is caused by fluctuations during the data collection. Also new is the concept of an embedded acquisition server and an associated client-server software architecture. This leaves the spectrometer independent of the client computer, thus giving the user the opportunity to control the system via an operating system and location of choice, like the cloud.
In 2021, the upgrades will continue by acquiring new probes. The new cryoprobes will allow detection of 19F, which is a suitable marker for following the compounds within the living cells as there is no natural fluorine background. We will also add a dedicated diffusion probe that allows to study molecular size based on the diffusion properties of the molecules. This is an experiment often requested by our users, but the current equipment does not provide sufficient accuracy for this purpose.