NMR - Nuclear Magnetic Resonance

Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful instrument that allows you to explore the electronic environment of atoms, by using a large magnet that probes the intrinsic spin properties of atomic nuclei when under a powerful magnetic field.

This technique is mostly used by chemists for determining the structure of small molecules, which allows the analysis of chemical samples, biological compounds, and medicines.

The basics:

The NMR is based on the principle that all nuclei are electrically charged, and many nuclei have spin. Once the magnetic field is applied, an energy transfer occurs between the base energy and the higher energy level.

The energy transfer takes place at a wavelength that corresponds to radio frequencies and when the spin returns to its base level, energy is emitted at the same frequency. The signal is then measured and processed and an NMR spectrum is mapped.

Interpretation of signals:

• Chemical shift: Gives information about the nucleus’ chemical composition.

• Spin-Spin coupling constant: Provides information about the adjacent atoms.

• Relaxation time: Provides information on molecular dynamics.

• Signal intensity: Quantitative information.

Interpretation of signals:

• Gives structural information about a range of different elements in molecules.

• Mainly used for the determination of the structure of molecules in a solution.

• Provides information on how molecules interact.

• Can determine shapes and structures of larger molecules.

• Used to evaluate the components in food.

• Used frequently in pharmaceutical science and medicine.