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 How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>