It is interesting times in the world of NMR – there are a number of new permanent magnet NMR systems hitting the market. I have seen a number of announcements appearing on LinkedIn and other sites in recent days and then there was a question asked about Cryogen-free NMR systems on the AMMRL server. There is a little confusion out there about who is doing what and what these newer NMR systems are capable of. We (Process NMR Associates and Aspect Italia) have been in the market with a high resolution 60 MHz system (3, 5, or 10mm sample tube) since 1997. Anasazi Instruments have been quitely selling hundreds of 60 and 90 MHz FT-NMR systems based on refurbished or newly manufactured Varian EM-360 and EM-390. New to the scene and making a splash with their marketing campaigns are Picospin (300 micron sample tube, 45 Mhz), Nanalysis (3, 5mm sample tube, 60 MHz). Finally, there is a system from Magritek/ACT (5mm sample tube, 42.5 MHz) that has been re-packaged and is now out there in the world. These systems all produce spectra and can be used in the traditional manner that current supercon systems are utilized. Time-Domain (TD) NMR systems should not be confused with these platforms – TD-NMR spectrometer manufacturers include Cosa-Xentaur, Bruker, Oxford Instruments, SpinLock, MR-Resources – which are used typically for hydrogen content, rheology, simple phase measurements (solid fat, water in oil, oil in water, porosity measurements utilizing relaxation analysis.
For the past 17 years we have been actively developing applications for permanent magnet systems shimmed to approximately 3 Hz at peak half height. The new magnet designs are robust and readily shims to 1-2 Hz at half height using 5 or 3 mm NMR tubes. 3 Hz at half height is possible for 10 mm NMR tubes. In the past the focus was in on-line applications in refining and petrochemical and lab systems were not actively marketed. With the third generation of NMR instrument it is time for these robust, non-cryogen, permanent magnet systems to be applied in laboratory and general quality testing applications.
In our laboratory we have an application development advantage in that we have high field 300 MHz NMR systems that are active in commercial NMR analysis and in high field method development. We also have ESR, FTIR-ATR, GC, moisture measurements, and other instruments that we can bring to bear on applications. We can readily develop 60 MHz applications using the 300 MHz NMR data as the basis set to provide primary parameters for analysis or to answer questions about the spectral overlaps that inevitably occur in 60 MHz data sets where 1 ppm on the spectrum axis represents only 60 Hz rather than 300 Hz. When a high field NMR spectroscopist observes a data comparison of spectra obtained at 60 MHz to the same spectrum obtained at 300 MHz (a resolution that most are familiar with) the penny suddenly drops concerning the possibilities that exist for NMR analysis at this field and an appreciation for the work that was performed for the first 30 years of NMR technology on 40 and 60 MHz CW NMR’s. We have become accustomed to our big supercon magnets and have forgotten what can be accomplished at 60 MHz. In these days of powerful computers for multivariate analysis and the ability ot perform global spectral deconvolution (GSD) the ability to develop killer-apps for bench-top, at-line, or in-line applications of 1H/31P/19F/23Na/11B NMR for 110V powered systems is here. The application of chemometrics and GSD at 60 MHz can allow the lower resolution issue of peak overlap to be overcome.
Comparing spectra obtained on our 300 MHz systems to the same samples on the 60 Mhz systems. Direct comparisons of the data make you realize that though the resolution isn’t anywhere near the same – the information is present in the 60 MHz spectrum. In the links below I have included a number of PDFs showing comparisons of complex essential oil spectra, fish oil and vegetable oils (looking at omega-3 fatty acid content), polyurethane adhesive polymers, shale oil, gasoline and a spectrum of Poloxamer which is a oxyethylene-oxypropylene copolymer utilized in the pharmaceutical industry that has an NMR based USP/NF method associated with it to determine the oxyethylene content.
Process NMR is actively involved in development of NMR applications utilizing 60 MHz or 300 MHz NMR data. We can develop applications for you and also provide the robust, proven instrumentation that can make affordable, cryogen-free NMR analysis a common automated laboratory tool. We are also looking to prove the utility of this excellent technology in all industrial sectors – if you have an application and would like to see a feasibility study we would be happy to provide such an opportunity. We have NMR systems looking for things to do! Please contact us if you feel you have an application where NMR may provide an answer through direct measurement or chemometric calibration. We are also interested in developing multi-spectroscopy technique data fusion applications where NMR and IR are combined to provide “better answers”.