Formation of odd-electron product ions in collision-induced fragmentation of electrospray-generated protonated cathinone derivatives: aryl α-primary amino ketones

Authors

  • Emilia Fornal

    Corresponding author
    1. Chemistry Department, The John Paul II Catholic University of Lublin, Lublin, Poland
    • Laboratory of Separation and Spectroscopic Method Applications, Center for Interdisciplinary Research, The John Paul II Catholic University of Lublin, Lublin, Poland
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Correspondence to: E. Fornal, Chemistry Department, The John Paul II Catholic University of Lublin, al. Krasnicka 102, 20-718 Lublin, Poland.

E-mail: efornal@kul.lublin.pl

Abstract

RATIONALE

Modification of the even-electron rule for fragmentation reactions of protonated molecules (even electron ions) may be necessary to interpret the liquid chromatography/mass spectrometry (LC/MS) spectra of aryl α-primary amino ketones as new designer drugs.

METHODS

Collision-induced fragmentation of 38 protonated cathinone derivatives generated by electrospray ionisation (ESI) was examined by hybrid quadrupole time-of-flight mass spectrometry (Q-TOF MS).

RESULTS

Q-TOF MS revealed that odd-electron product ions are often formed by collision-induced dissociation (CID) of protonated aryl α-primary amino ketones, contradicting the even-electron rule. Radical cations were among the most characteristic and most abundant ions in the CID-MS/MS product spectra, and were usually represented by basic peaks in the spectra.

CONCLUSIONS

To help elucidate the correct structures of new aryl α-primary amino ketone drugs by LC/MS/MS, it is essential to include odd-electron product ions in the data interpretation rules. Even and odd numbers of valence electrons in the product ions should be allowed in data interpretation. Copyright © 2013 John Wiley & Sons, Ltd.

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