Nuclear magnetic resonance is a technique used to identify
or to characterize a chemical or mixture of chemicals. In this test, a sample is exposed to a strong
magnetic field and a weak, oscillating magnetic field. The oscillating field causes the atoms within
the sample to produce an electromagnetic signal that is characteristic to the
atoms’ nuclei. Because this signal
shifts in response to bonds with neighboring atoms, the molecular structure of
a sample can be determined from the resulting NMR spectrum.