Fixed-Charge Generation Derivatization for the Analysis of Carbonyl Compounds by Electrospray Ionization Mass Spectrometry

The fixed-charge generation derivatization approach based on a reaction with ω-N,N-dimethylaminoalkylamines followed by quaternization with alkyl halides was applied to the analysis of aliphatic aldehydes and ketones, as well as ketosteroids by electrospray ionization (ESI) mass spectrometry. Both stages of reaction proceed quantitatively, and the registered ESI mass spectra of the products contain abundant peaks of the corresponding ammonium cations. In most cases, the dissociation of the last named compounds under collision activation results only in the loss of the terminal trialkylamino group as a neutral species. Such predictable fragmentation can be used for developing of highly sensitive methods of analysis based on selected reaction monitoring.