Instrument: Bruker Avance III 500 equipped with CP-MAS H/X (solid probe)
Nuclear Magnetic Resonance (NMR) spectroscopy is an exquisitely sensitive method for analysing the local magnetic environments of atoms. Within molecules, every atom affects the magnet environment of other atoms, particularly when they are close together in space or physically bonded to each othetr.
By monitoring the magnetic environment of the atoms we can determine the structure. of molecules, either in isolation or when interacting with other molecules
Since every conceivable environmental condition has a cumulative effect on this magnetic environment - such as molecular interactions, temperature, pH, solution environment - NMR spectroscopy is a very versatile method of analysis.
NMR is typically used for structure determination of small molecules, such as cehmicals or small biomolecules. NMR can also by used to investigate mixtures of molecules and can even solve 3-dimensional structures of proteins.
NMR spectroscopy relies upon exposing the sample of interest to an enormously strong magnetic field, approximately a quarter of a million times as strong as the magnetic field of the Earth, generated by a superconducting magnet.
Once exposed to these conditions, each atom within the sample becomes a sensitive barometer of its environment, and will report back on any changes it experiences, such as to temperature, pH, concentration or intra- and inter-molecular interactions.
We have the capabilities to routinely analyse a wide variety of elements in a fully automated way, such as hydrogen, carbon, phosphorous and fluorine. Analysis times vary, depending on the sample conditions and analysis desired, but usually take only a few minutes.
Analysis of complex mixtures, such as: formulation, identification and quantification of impurities, food forgery, stability studies, metabolomics and reaction monitoring.
Elucidating the chemical and three-dimensional structures of compounds and polymers.
Analysing the behaviour of molecules as they interact with their environments.
NMR spectroscopy can be fully quantitative.
We have both solution and solid NMR spectroscopy capabilities. Solid samples need to be provided ground as finely as possible with the size of the ground material being roughly equivalent to a grain of rice.
Samples to be analysed in the liquid phase need to be provided in a quantity that will provide half a mL of at least a 100 μM concentration. Although less material can be worked with, analysis times will be increased.
NMR spectroscopy is completely non-destructive, and therefore results in zero sample loss. NMR spectroscopy can also cope with severely contaminated samples.