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NMR

NMRNuclear Magnetic Resonance (NMR) spectroscopy

NMR spectroscopy is an analytical technique used to determine the chemical molecular structure of a compound. NMR provides both quantitative and qualitative data on the composition of a sample. This technique can be used for quality control, for research, to identify an unknown, or to determine the content and purity of a sample.

A simplified description of NMR is that the sample, dissolved in a liquid, is placed into the instrument, which contains a magnetic field. A radio frequency pulse is then sent through the sample solution in order to orient the magnetic moments of the nuclei in the solution. As the magnetic moments relax, they exhibit a free induction decay. The free induction decay is Fourier transformed into a NMR spectrum. The NMR spectrum displays chemical shifts for the individual nuclei; and from these chemical shifts, the structure of the compound can be determined.