By Khari Williams, Freelance Writer 
The UWI Chemistry Department's new Bruker Avance 500 Megahertz NMR spectrometer is one of the most advanced devices used to analyse chemicals. Department head Tara Dasgupta (right) and Werner Fleck-Chatelain, counsellor and deputy head of mission at the German embassy, examine the machine during its official unveiling. - Michael Sloley /Freelance Photographer
THE UNVEILING of the new 500 Megahertz nuclear magnetic resonance spectrometer last Tuesday by the University of the West Indies' (UWI's) Chemistry Department now gives students and researchers access to cutting-edge technology to identify chemical substances.
Non-chemists may not understand how the NMR spectrometer works, or why the department and the university paid the handsome sum of US$500,000 for it, but the device is seen as one of, if not the most important machine for the analysis of chemical substances.
A detailed account of the inner workings of an NMR spectrometer is complex but the machine works on some basic principles of science. As the name suggests, and as the large warning sign on the laboratory door declares, one of the fundamental components of the NMR spectrometer is a powerful magnet. Hydrogen and carbon-13 atoms because of the unpaired particles in their nuclei, also have a magnetic field, and when they are placed in the spectrometer's magnetic field they will exist in one of two states of different energies aligned with or against the magnetic field.
The samples are bombarded with radio waves, which are absorbed by the nuclei and cause them to move between the two energy states. The amount of absorption differs for each type of nucleus, and that is a key factor in the detection of different types of atoms, as different nuclei will require the absorption of different radio frequencies to move from one energy state to the other. That frequency is recorded by the spectrometer as a series of peaks called a spectrum, and the composition of the substance in question can be determined by analysing the spectrum.
The technique is similar to that used in magnetic resonance imaging (MRI) and has many applications in scientific research. Professor William Okamura at the University of California-Riverside has studied the form and function of Vitamin D3 using NMR in order to ascertain its position in biochemical pathways in the human body. NMR has even been used on another planet - a gamma ray spectrometer onboard a NASA spacecraft revealed large amounts of hydrogen in the South Pole of Mars, a sign that water may be in the region.
Bruker BioSpin, the company that built the NMR spectrometer at UWI, built the world's first commercial pulsed spectrometer in 1963 and four years later constructed the first multinuclear high-resolution NMR spectrometer.
