Tryptamine: a Reactive Matrix for MALDI Mass Spectrometry

A possibility of using tryptamine as a reactive matrix for the analysis of non-polar carbonyl compounds by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry has been shown. Presence of a terminal primary amine group in the tryptamine molecule predetermines the formation of Schiff bases from aliphatic and alicyclic carbonyl compounds. No additional matrix compounds are necessary to register MALDI mass spectra, because the excess of the derivatization agent plays the role of a matrix. MALDI mass spectra demonstrate high efficiency of desorption/ionization of the derivatives. To discover reactive matrices, a set of aromatic primary amines (mainly substituted anilines) has been tested, but they have not demonstrated matrix properties.