How to Interpret a Mass Spectrum Containing Ions that Undergo Rearrangement - Part 5

The McLafferty rearrangement is arguably one of the most captivating rearrangement reactions in analytical chemistry!


A rearrangement is observed in the gas chromatography-mass spectrometry (GC-MS) electron ionization (EI) during the dissociation of organic molecules, say, fatty acid methyl esters (FAME). The charge may sometimes be retained by the other (neutral) species for each cleavage process, and both fragment/product ions are observed.

Derivatization of a fatty acid (FA) to its methyl ester (FAME) is done before GC-MS to achieve better volatility and thermostability.



Click to enlarge the image

M = Molecular, EE = Even electron, OE = Odd electron

Is the infographic easy enough to digest❓ Let Chemaficionado know at mychemistryhomework@gmail.com❗

References:

(1)    Wikipedia Contributors. Gas chromatography–mass spectrometry. Wikipedia. https://en.wikipedia.org/wiki/Gas_chromatography%E2%80%93mass_spectrometry.

(2)    SDBS, Spectral Database for Organic Compounds, AIST. sdbs.db.aist.go.jp. https://sdbs.db.aist.go.jp/. 

(3)    Wikipedia Contributors. Fatty acid methyl ester. Wikipedia. https://en.wikipedia.org/wiki/Fatty_acid_methyl_ester.

(4)    Wikipedia Contributors. McLafferty rearrangement. Wikipedia.

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