NMR Spectrometers and Their Work

By Chad No comments

A wide variety of scientific instruments are used to study items large and small, and even individual molecules can now be observed. Meanwhile, spectrometers and 60 MHz multinuclear NMR devices are useful for studying rocks, and NMR spectrometer applications in a lab are many. Some are quite small, with benchtop NMR spectrometers being available for purchase. What is a 60 MHz multinuclear NMR device capable of, and hold old is this technology, anyway? What is there to know?

All About NMR Spectroscopy

NMR stands for “nuclear magnetic resonance,” and it ranks among the most important analytical methods out there for modern chemistry. This technology was innovated all the way back in the year 1946, when Felix Bloch and Edward Mills Purcell, and they shared a Nobel Prize for this work in 1952. In the 1950s, the first commercial spectrometers were built, and they rapidly became a vital tool for chemists. At first, these commercial spectrometers made use of conventional electromagnets and permanent magnets, but in the 1960s, they started using superconducting magnets instead. Overall, NMR spectrometers vary from 60 MHz to 100 MHz models whenever they use permanent or electromagents, and typical 60 MHz multinuclear NMR spectroscopes can be found all over the wholesale market today.

Using A 60 MHz Multinuclear NMR Spectroscope

It may be noted that these NMR spectroscopes do not necessarily operate alone; more often, they are used to compliment other scientific instruments, so full and detailed analyses can be done. Often, it is used to study and analyze rock core samples, and geoscience and petrophysics alike call for defining the rock core’s porosity. Mercury porosimetry will give a scientist detail about the rock core’s pore sizes and locations, as well as the fluid itself. While mercury flows through the rock, the scientist can study the fluid’s behavior. This is done so when people break a well, they will know how much oil is going to flow, and how much of it will be bound by capillary action. But this science is not perfectly precise, so NMR spectroscopy is used alongside it, to make the readings more accurate.

The good news is that using a 60 MHz multinuclear NMR is not terribly skill intensive. In fact, a scientist with little understanding of NMR can make good use of one, and its controls are fairly simple and intuitive. They are user friendly, to put it in other terms, meaning any scientist at a lab can make use of one. These are also helpful for reservoir engineers, so they can study the porousness of rocks nearby.

Another useful technique is to use a centrifuge and 1-D profiling, which will record NMR signals in one dimension, along the rock core’s axis. Once this is done, scientists can get a detailed measurement of the fluid’s distribution along that core sample. This process is relatively fast and inexpensive, and can yield a lot of useful data.

When a rock sample is placed inside a magnetic field and excited with a pulse of radio frequency (RF) energy, it gives off NMR signals from its brine or oil inside, which can then be read. As the pulse fades, the NMR signal appears, and it will naturally decay away (T2 time). The signal’s amplitude indicates how much fluid the rock core has, and the T2 signal will describe the liquid’s physical environment. Similar fluids may yield similar T2 as each other, though, so to avoid confusion, their diffusion characteristics are noted, too.

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