Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Small But Super

31.05.2010
Lightweight, handy magnets for portable NMR spectrometers

High-resolution nuclear magnetic resonance (NMR) spectrometry is one of the most powerful analytical tools for the precise determination of molecular structures and dynamics.

To attain a high resolution, very strong magnetic fields are required, which are produced by superconducting electromagnets. Federico Casanova and his co-workers at the RWTH In Aachen (Germany) have now developed a light, permanent magnet that is suitable for NMR and fits in the palm of your hand. As the researchers report in the journal Angewandte Chemie, this could represent the cornerstone for portable, high-resolution NMR instruments.

In the 1960s and 1970s, NMR spectrometers used permanent magnets, which were not as massive as the superconducting magnets used today. With modern, improved permanent magnets, it should theoretically be possible to build handy, robust devices. This would make it possible to obtain NMR spectra that are about a third as sensitive as those obtained with standard-sized superconducting magnets. “This would be an acceptable concession for a small and portable NMR system,” says Casanova. “However, there is one problem: As the magnet gets smaller, the dimensions of the homogenous (uniform) magnetic field also decrease, making the sample volume smaller. Reduction of the sample volume affects the signal-to-noise ratio.”

The Aachen team has now developed a small permanent magnet weighing only 500 g with an unusually homogenous magnetic field that allows a standard-sized NMR tube to be used. Their success is due to a Halbach array: individual magnetic blocks are assembled into a cylinder so that the direction of their magnetization is tuned to produce an especially homogenous field within the cylinder. The researchers connect three Halbach rings whose diameter is optimized to compensate for the distortion of the magnetic field at the ends of the cylindrical inner chamber. In this way a sufficiently large homogenous magnetic field is produced inside the cylinder, which is large enough for a standard NMR tube. To even out the inhomogeneities originating from the granularity of the magnetic material, each ring consists of trapezoidal magnetic blocks with gaps in between. Inside the gaps are rectangular magnetic blocks that can be displaced radially to mechanically adjust (“shim”) the magnetic field.

“Spectra we obtained show that our miniature magnet is suitable for high-resolution NMR spectroscopy with standard-sized sample tubes,” reports Casanova. “It would be easy to transport together with the spectrometer. This could allow high-resolution NMR spectroscopy to develop into a portable analytical technique for use on samples in the field.”

Author: Federico Casanova, RWTH Aachen (Germany), http://www.mc.rwth-aachen.de/

Title: Small Magnets for Portable NMR Spectrometers

Angewandte Chemie International Edition 2010, 49, No. 24, 4133–4135, Permalink to the article: http://dx.doi.org/10.1002/anie.201000221

Federico Casanova | Angewandte Chemie
Further information:
http://www.mc.rwth-aachen.de/
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht Making fuel out of thick air
08.12.2017 | DOE/Argonne National Laboratory

nachricht ‘Spying’ on the hidden geometry of complex networks through machine intelligence
08.12.2017 | Technische Universität Dresden

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>