Unsurpassed High Resolution NMR Spectrometers from Anasazi Instruments

Interview conducted by Alexander ChiltonSep 2 2015

Donald Bouchard, Business Development and Marketing Manager at Anasazi Instruments, spoke to AZoM about their range of high resolution NMR Spectrometers.

Could you provide our readers with an overview of the history of Anasazi Instruments and explain how the company has grown over the last 20 years since it was found in 1995?

Anasazi was founded in 1995 and got its start upgrading EM360 and EM390 CW NMR instruments. The concept was radical because a large number of people were skeptical that 60 and 90 MHz instruments could achieve the level of performance and range of experiments possible.

Both two-dimensional and multinuclear measurements were unheard of with these instruments, but we showed that it could be done with either 60 or 90 MHz magnets. Our first instrument was delivered in early 1996 to Lake Forest College, the first generation Eft-60.

What is remarkable about this system is that it continued to perform for the last 20 years.

For about the first 10 years of the company we offered both upgrades to customer’s EM360’s and EM390’s and we also refurbished many magnets and sold complete systems. In about 2003, we began selling these instruments in Latin America with great success.

After about 10 years of success, we started to feel that we were saturating the market, and the number of customers who had EM magnets to upgrade were dwindling. The number of customers wanting 60 and 90 MHz systems wasn’t declining, so in 2008 we delivered the first Aii-60 magnet to the Milwaukee Area Technical College.

This achievement was remarkable because even to this day a large percentage of this instrument is manufactured in the City of Indianapolis.  Even the AlNiCo magnet material is manufactured close to our factory located along the southern edge of Indianapolis.

After about 9 months we started delivering the Aii-90, 90 MHz NMR magnets for the Eft-90, the first being delivered to the University of Indianapolis. This was also a remarkable achievement because 90 MHz permanent magnets represent the state-of-the-art for magnet design.

Since these developments we have continued our commitment to deliver instruments which are unsurpassed in performance. The results speak for themselves, and we invite you to learn more. We also freely share customers closest to you, so you can ask our customers about our reputation.

Could you please explain the basic principle of how nuclear magnetic resonance (NMR) spectroscopy works?

In absorption spectroscopy,one shines light on a sample and a chromophore absorbs specific wavelengths of light and the instrument creates a plot of absorbance versus wavelength. The absorbance reading reflects the concentration of the chromophore, based on the molar absorptivity of the chromophore, which we can determine using Beer's Law. Here the sample is absorbing the light energy to effect the electronic transition and the detector directly detects the frequency specific light intensity.

A second analog is fluorescence spectroscopy which is similar to magnetic resonance because it involves absorption of light and its subsequent radiation. In fluorescence a sample can be excited by a wide (Xe lamp) or narrow-band (laser) light source. The excited electronic state relaxes and emits a photon and the wavelength of the photon's energy (wavelength) is specific to many parameters which can allow for quantitation and identification of the chromophore. Here the sample is emitting light (photon) and the detector (usually perpendicular to the exciting source) detects the light emitted from the sample.

So now we move to Magnetic Resonance which requires first and foremost, a magnetic field to "polarize the spins".  Certain elements have odd numbers of protons and neutrons, for example, ¹H has a single proton and has the property of "spin". On the other hand, ¹²C, has an even number of protons and and even number of protons and neutrons and therefore, has no spin, so there is no NMR phenomenon observable on ¹²C Fortunately, carbon has a stable isotope of ¹³C with an odd number of neutrons and an even number of protons, so ¹³C has the property of spin.  Additionally, the electron also has the property of spin and plays an enormous role in the richness of NMR spectroscopy.

When you place a spinning charge (¹H or ¹³C) in a magnetic field, it precesses about the field axis. The frequency of the precession is determined by the strength of the magnetic field and the "gyromagnetic ratio" which is a constant for every isotope. The frequency of the precession for the magnetic field strengths produced by permanent magnets can be as high 90 MHz which is a field strength of 2.1 Telsa. So we can think about the NMR experiment similar to a fluorescence experiment where the sample is immersed in a magnetic field to achieve the initial polarization.

We can "excite" the spins which are precessing in the magnetic field with a radiofrequency field equal to the frequency of precession.  In a simplistic way we freeze the precessing spin and replace it with a vector which is aligned with the magnetic field.  When we apply a short burst of radiofrequency field to the spins, the spin rotates such that it is perpendicular to the applied field, this is the "excited state".

After we turn off the radiofrequency field, the spin returns to the ground state, but it also emits a signal which is then detected by the antenna and the signal is recorded using a computer.

What is remarkable about magnetic resonance is the effect which chemical structure and the changes in the electronic environment around a particular nucleus has on the resonance frequency. Tiny perturbations as small as one part in a billion can be detected using this method.  

When a student studies organic chemistry or analytical chemistry, this interaction of matter with radiation brings a wealth of understanding about the tiny physical realm which is the study of chemistry.

Anasazi Instruments manufactures the Eft 60 and 90 MHz permanent magnet NMR spectrometers. Could you provide our readers with a summary of these instruments and explain how they differ from each other?

The Eft-60 is a 60 MHz NMR instrument and has a smaller magnet (strength of 1.4 Telsa) compared to the Eft-90 having a magnet with a field strength of 2.1 Tesla. To achieve the parts per billion homogeneity requirements demanded by practicing chemists the magnets have to fairly large. In fact, you cannot make NMR instruments smaller without making great sacrifices that have enormous effects on the quality of the spectra. This is why we don't pretend we can make suitable NMR instruments that fit on a bench top.  

The Eft-60 has excellent sensitivity and resolution because of the large volume of homogeneity of the magnetic field. The Eft-60 is the highest resolution and highest sensitivity of any permanent magnet NMR instrument with the exception of the Eft-90. The Eft-90 offers a similar volume of homogeneity, but the size of the magnet is larger. The Eft-90 has twice the sensitivity and 50% better resolution than the Eft-60.

The reason why customers buy the Eft-90 over the Eft-60 is the improvement in resolution.  A chemist can measure larger molecules with less sample using the 90 MHz instrument.  Colleges looking to perform basic research can rely on the Eft-90 as a workhorse routine NMR instrument to measure ¹H, ¹³C, and multiple elements observable by NMR.

The Eft spectrometers offer cryogen-free operation to their users. Why is this an important factor to many people wanting to carry out NMR spectroscopy?

Give any chemist the opportunity to measure their spectra with a higher field, they will take it. 90 MHz is preferred over 60 MHz and naturally, 300 MHz is preferred over 90 MHz. However, 90 MHz is the practical limit of permanent magnet NMR instruments. In order to go higher in frequency, cryomagnets are the only practical option.

But cryomagnets require liquid helium cooling to maintain the superconducting state of the wire carrying the electric current with zero resistance producing enormously higher magnetic fields (300 MHz = 7.05 Tesla).

In 2015, the supply of liquid helium is uncertain and many small institutions are without a reliable supply of liquid helium.  The second the superconducting wire temperature goes above the 4.2 K temperature of liquid helium, poof, the magnetic field is gone. To recover from such a problem, you can't just refill the dewar with liquid helium, it costs thousands of dollars and a highly skilled engineer to re-energize a superconducting magnet.

Because the Eft is a permanent magnet solution for NMR spectroscopy, there is no expense and maintenance of a superconducting magnet. You aren't tied to weekly nitrogen fills or the rigors of liquid helium fills, so there is much less stress involved in having an Eft-90 in your lab.

What are the key application areas which the Eft spectrometers can be used for?

Both the Eft-60 and Eft-90 offer the capability of ¹H NMR spectra, ¹³C NMR spectra and multinuclear spectra. No other benchtop NMR can address so many applications with a single instrument because the Eft is a general purpose NMR. It is freely programmable and can be highly customized for use in a quality control laboratory whether a simple one-button approach to assaying materials is required.

There are over 700 Eft's in use all over the world in applications of organic chemistry, analytical analysis, polymer analysis, chemical manufacturing, quality of incoming raw materials, purity of raw materials and process development.  There are few limitations to the Eft architecture. ¹H decoupling, polarization transfer, X-nucleus decoupling, quadrupolar nuclei observation like 7Li, 11B in brines and organolithium and organoborane compounds and 23Na quantitation in foods.

What are the main advantages of these instruments compared to other currently available NMR spectrometers and what do you believe gives Anasazi Instruments a competitive advantage within this market?

Without a doubt, the Eft-60 is the highest resolution, highest sensitivity pm-NMR instrument on the market.  It doesn't fit on a benchtop, but if you compare run times, number of scans required to achieve a specific signal to noise and the resolution required to resolve complex spectra, most chemists who care about their results, choose the Eft. Sure, the Eft is priced higher than some of the benchtop instruments, but quality isn't expensive, it's priceless.

Could you explain to our readers the advantages of using an Eft NMR spectrometer in a teaching laboratory?

In most teaching laboratories, you have 15-30 students who all need to run NMR spectra. Even if it sufficient to get a "quick and dirty" ¹H spectrum, you need to have run times of seconds, not minutes. This is just one of the advantages which the Eft provides. Not only are mg sample spectra acquired in seconds, the resulting spectra are more readily interpreted and free of many artifacts which arise from NMR instruments with a lower field. These artifacts are called "second-order effects" and complicate the spectrum. The only way to eliminate second-order effects is to run with a sufficiently high magnetic field such as 60 MHz.

Some budget conscious schools buy instrumentation with the hope that it will meet their needs, only to be sorely disappointed. Long run times, disgruntled students, and worse, unfulfilled students. The Eft-60 will allow students to measure complicated spectra faster and easier.  We like to highlight that the Eft-60 and Eft-90 can be readily incorporated into the existing curriculum because of its sensitivity and resolution.  Samples of a few milligrams can easily be recorded on either instrument in seconds not minutes.  The way the other bench top instruments work, the curriculum must be adapted and quite frankly, that’s the wrong way around.

You can't cheat physics and you can't hope to master organic chemistry without good understanding and that's what NMR does, it gives students hard data to a subject that can be difficult and the Eft results provide understanding and mastery.

Does Anasazi Instruments plan to launch any new products this year?

Anasazi Instruments is proud to announce the SC-1 robotic sample changer for unattended analysis. The SC-1 robotic sample changer is a collaborative robot which safely operates without the need to shield personnel working around the NMR.  If a user bumps any part of the robot, it stops.  The robot can be re-started with a software command from the operating software.

The sample racks are 25 positions and the instrument can beconfigured for up to 3 x 36 or 108 total samples.

Any sample can have several measurements, ¹H, ¹³C, or 2D measurements with a pre-defined signal to noise ratio for a completely automated measurement solution.  Data is available via email or via a web server interface for analysis.

The SC-1 is available to any customer who currently has an Aii-60 or Aii-90 magnet.  It is a field upgrade with on-site installation included in the upgrade price.

Installation of the SC-1 robot does not preclude manual operation, the robot can be parked so that it is out of the way and samples can be run manually.

Does Anasazi Instruments offer a warranty on its hardware and software to its customers?

Anasazi Instruments is the only manufacturer that offers a 5 year warranty on both new and refurbished instruments. We offer refurbished instruments which will save customers money and they come with the same strong support and warranty as our new instruments.

We have instrument which have been in the field for 20 years. Obsolete is not a word we like to use. Additionally, we offer upgrade pathways to customers with old PCs so that the most up-to-date software will enhance a user's experience.

In which countries around the world do you currently distribute your NMR spectrometers to? Are there any plans to expand Anasazi Instrument’s distribution to other areas in the future?

We are aggressively expanding our sales and distribution to all five continents. We currently have instruments on all five continents. Because the Eft is so rugged and durable, these are the only instruments available to practicing chemists who have no hope of a ready supply of liquid heilum. Anasazi is a group of chemists who love helping chemists pursue their goals.

In fact, there are more Eft's in daily use around the world than all the other permanent magnet NMR instruments... combined. We are proud of our contribution to the permanent magnet NMR users around the world and we look forward to the future.

Where can our readers find out more information about Anasazi Instruments’ Eft 60 and 90 MHz NMR spectrometers and the company more generally?

Go to https://www.aiinmr.com/about-us-nmr-spectroscopy-instruments/ or more information, or email us at [email protected]. You'll be glad you did!

About Donald Bouchard

Donald Bouchard is passionate about nuclear magnetic resonance and enjoys working with state-of-the-art products.

He also enjoys educating people in how to maximize the value of their NMR/MRI investment and enjoy creating new markets for new and existing MR products.

Donald joined the sales and marketing team at Anasazi Instruments in 2003 after previously working as a sales director and a research scientist at Colgate Palmolive before that.

Donald holds a B.Sc. undergraduate degree in Chemistry from Florida State University, a masters M.Sc. degree from Emory University for his thesis on "Polyoxometalates as Soluble Analogues for Heterogeneous Catalysis".