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 The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

nachricht How protein islands form
15.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>