Instead of requiring dedicated infrastructure, rooms and extensive installations these benchtop instruments can be placed directly on the bench in a lab and moved as necessary (e.g., to the fumehood).
They differ from relaxometers in that they can be used to measure high resolution NMR spectra and are not limited to the determination of relaxation or diffusion parameters (e.g., T1, T2 and D).
Since the early 2000s there has been a renaissance in permanent-magnet technology and design,[4] with advances sufficient to allow development of much smaller NMR instruments with useful resolution and sensitivity for education, research and industrial applications.
[5] Samarium–cobalt and neodymium hard ferromagnets have reduced the size of NMR permanent magnets, and fields up to 2.9 T have been reached, corresponding to a 125 MHz proton Larmor frequency.
They require only single phase local power, and with UPS systems can be made portable and can perform NMR analyses at different points in a manufacturing area.
The currently available spectrometers are easily moved from one location to another, including some that are mounted on portable trolleys with continuous power supplies.
[6] Another related difficulty is that currently available spectrometers do not support elevated sample temperatures which may be required for some in-situ measurements in chemical reactions.
Cheaper, more robust, and more versatile medium and low field instruments have sufficient sensitivity and resolution for reaction monitoring and QA/QC analyses.
A small (7 x 5.75 x 11.5”) 45 MHz spectrometer with good resolution (< 1.8 Hz) and mid-to-low-range sensitivity that weighs 4.76 kg (10.5 lbs) and can acquire a 1D 1H or 19F spectra.
Depending on the model of instrument, it can perform 1D 1H, 13C{1H}, 19F, 31P, 31P{1H}, COSY, JRES, DEPT, APT, HSQC, HSQC-ME, HMBC, T1 and T2 experiments.
X-Pulse is the only benchtop NMR system to offer a full broadband X channel for the allowing the measurement of 1H,19F, 13C, 31P, 7Li, 29Si, 11B and 23Na on a single probe.
A large range of 1D and 2D measurements can be performed on all nuclei, 1D spectra, T1, T2, HETCOR, COSY, HSQC, HMBC, JRES, and many others including solvent suppression and selective excitation.
Instrument control comes from the SpinFlow workflow package, while the processing and manipulation of data is achieved using third-party NMR software suites.
Other features that support automated and hyphenated applications are stable shim, open-source Python control software, and front-panel fluid connections.