Infrared multiphoton dissociation

Infrared multiphoton dissociation (IRMPD) is a technique used in mass spectrometry to fragment molecules in the gas phase usually for structural analysis of the original (parent) molecule. ^[1]

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How it works

An infrared laser is directed through a window into the vacuum of the mass spectrometer where the ions are. The mechanism of fragmentation involves the absorption by a given ion of multiple infrared photons. The parent ion becomes excited into more energetic vibrational states until a bond(s) is broken resulting in gas phase fragments of the parent ion.

IRMPD is most often used in Fourier transform ion cyclotron resonance mass spectrometry.^[2]

See also

• Infrared spectroscopy
• Blackbody infrared radiative dissociation
• Electron capture dissociation
• Collision-induced dissociation is another, more common, method to fragment gas phase ions.

References