Mass Spectrometry & Spectroscopy
Benchtop NMR – Bringing New Access to Technology to the Next Generation of Scientists
Dr Venita Decker, Product Manager Compact NMR (TD/FT), Bruker Ettlingen, Bruker BioSpin, Rudolf-Plank-Straße 23, 76275 Ettlingen, Germany Correspondence email:
info@bruker.com
The discovery of Nuclear Magnetic Resonance (NMR) spectroscopy was published independently in 1946 by Felix Bloch and Edward Purcell. Their pioneering work showed that NMR can be used to analyse the molecular structure of material in condensed matter and was the catalyst for further NMR studies. Bloch and Purcell were jointly awarded the 1952 Nobel Prize in Physics for their work on NMR and chemical shifts.
The rapid development of NMR followed the commercial production of NMR systems with homogeneous (uniform electric fi eld) electromagnets. In the 1950s-60s, improvements in magnet design and construction allowed an increase in fi eld strength, raising the frequency of 1H NMR spectroscopy from 40 MHz to up to 100 MHz. However, to achieve these frequencies, the size of electromagnets became substantial – often well over 1 m3
in the mid-1970s, often 60-90 MHz, were also of considerable size. Often known as ‘Alnico’ magnets, comprising the magnetic materials aluminium, nickel, and cobalt, some remain magnetised some 60 years later, and several are still in use thanks to updated electronics.
In the 1970s, fi rms began commercially manufacturing NMR spectrometers and from 1990, researchers, academics and businesses were able to purchase these commercial instruments. Since then, improvements in magnet technology have allowed increases in 1H NMR frequency, reaching 750 MHz in the 1990s to beyond 1.2 GHz in modern instruments.
and 1 metric ton. Permanent magnets developed
Why education has missed out on NMR
High-fi eld NMR spectrometers have typically been used in scientifi c laboratories for decades but, although very powerful, such instruments are not commonplace in educational institutions, due to their size and scalability, and the practicalities of housing such large-scale equipment. There is an argument that this must change as technology advances further, to allow those in education access to NMR technology to gain valuable experimental experience in analytical techniques.
There are several reasons why academia has previously missed out on NMR. First and foremost, NMR systems are expensive and universities, schools and colleges facing a lack of funding for investment in science, technology, engineering, mathematics subjects (STEM) has made NMR unaffordable for many educational institutions.
The practicality of housing an NMR system is another challenge, with NMR instruments relying on being installed in their own air-conditioned room which needs constant attention and maintenance to provide best performance. Their size also means they cannot be transported easily to other environments.
With universities and schools closed for weeks at a time, it is diffi cult to maintain instruments correctly. Superconducting magnets must always remain on and liquid helium and nitrogen must be regularly re-fi lled. Educational institutions are also faced with the issue that in order to use an NMR spectrometer, users have to be trained in how to use it – a complex and time consuming process that is often out of reach for universities and schools.
Skills shortage
The general lack of access to technology has led to a global shortage of students graduating in the fi eld of scientifi c research. According to The Guardian, to become a scientist, students need to have practical awareness of experimentations - but gaining lab experience as an undergraduate is diffi cult. The Guardian further states that, in the UK, bioscience students participate in around three to nine hours of lab time per week, which falls far below the level of training needed to proceed into a job role post-university [1]. This makes on-the-job training inevitable which is time-consuming and costly.
Access to scientifi c equipment for undergraduates encourages individuals to pursue STEM subjects, which, in turn, will address the current skills shortage. According to the Economic Times, just two years ago there were around four million vacancies in STEM jobs in the US and just 40,000 graduates with STEM degrees [2]. This huge gap highlights the need to encourage people from a young age to pursue a career in STEM and industry and academia can work together to support this goal.
Given the valuable learning opportunities available through NMR spectroscopy, many educational institutions have so far signifi cantly missed out on the potential that the technology has to offer.
The solution is benchtop NMR
A benchtop NMR spectrometer offers a compact and portable solution. It does not require dedicated infrastructure, extensive maintenance, or an installation process and can simply be placed on a benchtop and plugged in. Benchtop spectrometers offer improved workfl ows, particularly for novice users, as they are intuitive in use and do not require extensive training.
The advantages of benchtop NMR systems are paving the way for the introduction of this technology in education:
• Specialist NMR expertise is not required • Same direct quantifi cation and deep structural information as high-fi eld NMR • Compact benchtop size • No additional infrastructure needed • Cryogen-free permanent magnets – no need to re-fi ll liquid helium or nitrogen • Operates from a single standard power socket • Easy maintenance and optimum cost of ownership.
Some benchtop systems can be operated with the same, industry-standard software that is used on high-fi eld NMR systems (e.g. Bruker’s Fourier 80 can be operated with TopSpin software). This allows the students to become familiar with NMR in general, as well as the operation of high-fi eld NMR instruments at the same time.
Similar to high-fi eld NMR systems, the compact benchtop instrument can be brought into many different fi elds of application, such as food and beverage analysis and forensics. This means that as well as teaching students about a range of different analytical techniques, academics can also continue to observe high-accuracy data and experiments directly from the benchtop.
With benchtop NMR spectrometers offering the reproducibility and stability of high- fi eld NMR technology in a more accessible, smaller instrument that can be installed on the lab bench, it is a good fi t for educational settings, such as universities, colleges, or even schools.
Benchtop NMR allows students to learn about NMR as a method and explore concepts such as chemical shift, coupling constants, relaxation, and pulses, as well as learning about advanced techniques such as selective excitation and solvent suppression. In an organic chemistry lab, students can check reactions, determine the yield and check the purity of reagents and products, as well as perform structure elucidation of organic molecules.
INTERNATIONAL LABMATE - NOVEMBER 2020
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