Question

Difference between Mass Spectrometry, Infrared spectroscopy(IR), & nuclear magnetic resonance spectroscopy(NMR)?

Answer 1

Infrared spectroscopy (IR) is absorption of low energy radiations by bonds. Absorption causes vibrational and rotational excitations of groups of atoms corresponding to the type of bonds. It helps identify functional groups present in a molecule. This is a widely used technique in synthetic laboratory. This is a non-destuctive technique and compounds after analysis can be recovered as it is.

Nuclear magnetic resonance spectroscopy (NMR) is absorption in radio frequency region of electromagnetic spectrum. NMR analysis tells us how many equivalent atoms of specific types are present in a molecule. They can be adjusted to the type of nucelus of interest say, 1H, 13C, 31P, etc. This is a very powerful tool in identification of structure of compounds and is widely used by organic and inorganic chemists. This is a non-destructive analytical tool, wherein, the compounds can be isolated back from solution after analysis is done.

Mass spectroscopy is a technique wherein, sample molecules are ionized by high energy electrons. Charge to mass ratio of formed ions is then measured and exact mass of molecules and fragments resulting from it can be obtained. This is a destructive analytical tool. Samples once analyzed cannot be recovered back.