Nuclear Magnetic Resonance Section

Nuclear Magnetic Resonance Spectroscopy (NMR) is a non-destructive technique (the sample is recovered intact after the experiments) that allows the study of almost any element (isotope) of the periodic table (1H, 13C, 31P, 15N, 23Na, 27Al, 29Si...). Molecular information is obtained by NMR spectra.

There is a huge variety of types of NMR spectra and each of them is sensitive to a type of molecular information (covalent or chemical bond structure, spatial closeness between atoms, molecular translational diffusion, rotational diffusion, etc.).  Modern NMR spectra can have one or more dimensions (1D, 2D, 3D, 4D...) which allows molecular information to be obtained in a fast, accurate manner and, at the same time, avoids problems in the analysis due to a possible congestion of signals.

NMR in solution

NMR in solution makes it possible to determine the three-dimensional and dynamic structure of molecules dissolved in H2O or in any other solvent. The molecular size range that can be studied ranges from small organic molecules and peptides to proteins or DNA with a size limit of up to about 80 kDa. By using NMR in solution, interactions can also be studied between molecules (e.g. drug-receptor interaction), molecular diffusion, analysis of impurities and degradation products, etc.

NMR of semi-solids with the HR-ME Las (High Resolution Magic Angle Spinning) technique for viscous samples, gels and biopsies.

This probe is used to obtain high-resolution NMR spectra with viscous and/or inhomogeneous samples, which allows sample rotation in the magic angle and gradients (PFG). Experiments of  the NMR of semi-solids are very similar to those on conventional liquid samples. This equipment is ideal for analysing the chemical composition of food products (cheese, chocolate and other emulsions), metabolic profiling of ex-vivo tissues or extracts, studying viscous high molecular weight polymers, analysis of fatty acids and fats in seeds. The combination of NMR diffusimetry techniques and the HR-MAS probe is a very powerful tool to analyse the components of a complex mixture without having to physically separate them.  

NMR of solids

Solid state NMR allows the study of physical and chemical properties of samples in crystalline or amorphous states. Applications include the determination of molecular structure, intermolecular packing in amorphous solids, material properties (flexibility, brittleness...), evolution of materials (e.g. evolution of the degree of hydration of a cement clinker, composition of organic and inorganic material in soils and study of heterogeneous samples in general).