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NMR (nuclear magnetic resonance) spectroscopy has long been an invaluable analytical method in industry for verification of chemical synthesis and compound characterization. The power of NMR spectroscopy is truly unparalleled in the arena of structural identification of organic and biochemical compounds. In combination with other services already offered by Exova, including Fourier Transform Infrared Spectroscopy (FTIR), elemental analysis and mass spectrometry, NMR will prove particularly useful to projects aimed at identification of chemical and pharmaceutical unknowns. Our NMR services are targeted primarily to corporate customers in the biotechnology, pharmaceutical, specialty chemical, nutraceutical, personal care, oil and petrochemical industries. |
NMR - IntroductionOur NMR SystemNMR ServicesNMR GMP ComplianceExample NMR Applications |
NMR - IntroductionNMR spectroscopy uses radiofrequency radiation to induce transitions between different nuclear spin states of samples in a magnetic field. NMR spectroscopy can be used for quantitative measurements, but it is most useful for determining the structure of molecules (along with FT-IR and mass spectrometry). The utility of NMR |
spectroscopy for structural characterization arises because different atoms in a molecule experience slightly different magnetic fields and therefore transitions at slightly different resonance frequencies in an NMR spectrum. Furthermore, splittings of the spectral lines arise due to interactions between different nuclei, which provides information about the proximity of different atoms in a molecule. A typical NMR spectrum is shown in Figure 1. |
Our NMR SystemThe NMR system was installed in the Santa Fe Springs facility in December 2008l operates at 500 MHz (resonance frequency for 1H). It has capabilities to study 1H and other nuclei (13C, 31P, 29Si, 19F, 2H, etc.). The new NMR spectrometer is capable of analyzing samples in solution state (by the majority of modern 1D and 2D NMR experiments) and in solid state (by CP/MAS, cross polarization/magic-angle-spinning spectroscopy). The instrument has variable |
temperature capabilities (ranging from -80 °C to +150 °C for solutions, and from -45 °C to +110 °C for solids). Figure 2 is an example of the main components of the NMR spectrometer, namely, the superconducting magnet, the console holding the electronics, and the computer workstation. The connectors for the various nuclei on the two probe heads (the 'antennas') are depicted in the bottom insets. The probe heads are inserted at the bottom; the sample, in an NMR glass tube (see top inset), is injected at the top of the magnet. |
Figure 2. NMR spectrometer with peripherals. Insets: Probe heads and NMR sample tube.
NMR ServicesWe plan to offer, first of all, a number of “routine” NMR services, ideal for product quality control, structure verification, structure elucidation of smaller molecules and/or evaluation of compound purity (including, for example, the purity check of heparin, recently mandated by FDA , as well as any other NMR tests mentioned in USP and EP monographs). Examples of solution-state NMR experiments in this category are: · 1D spectra of 1H, 13C, 19F and 31P · 2D {1H,1H} COSY, TOCSY and 2D {1H,13C} HSQC and HMBC
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Solid-state NMR is commonly used in the
analysis of polymorphs, particularly in the pharmaceutical area. Our
routine solid-state NMR services will include CP/MAS spectra of
13C, 29Si, 31P etc. We also look forward
to assisting customers who have needs for more advanced NMR applications
aimed at, for example, complete characterization of
compounds of modest structural complexity. Exova’s NMR services are expected to benefit a wide range of customers in chemistry, biochemistry, pharmacy, life sciences, and material sciences. More specifics can be found in the April 2010 issue of Analytical Digest. Please contact Jack Northington 562-948-2225 (ext 103) if you have any questions regarding NMR services that may be of interest to your company. |
NMR GMP ComplianceExova believes that it has one of the very few GMP compliant NMR systems existing in a commercial laboratory. GMP compliance starts with documented procedures such as a Standard Operating Procedure (SOP) for operation and maintenance, instrument run logs, and sample preparation logs. The system is qualified annually for instrument parameters such as sensitivity, |
resolution, line shape,
and pulse width for various nuclei. The instrument
software has been validated for file
security to 21 CFR Part 11 standards.
Operators are qualified through documented training.
While the system is used for several GMP compendial tests, Exova also provides research, method development and validation according to ICH guidelines |
