Electrospray ionisation tandem mass spectrometry in the characterisation of isomeric benzofurocoumarins

A set of aminoalkoxy-substituted, differently annullated furocoumarins, dif fering in the position of the aminoalkoxy chain and in the unsaturation lev el of the fused ring, has been subjected to electron impact and electrospra y ionisation (ESI) experiments. In order to achieve a distinct characterisa tion of isomeric compounds, which partially failed under electron impact co nditions, collision-induced dissociation experiments were performed on prot onated molecules. The breakdown curves obtained by varying the tickle volta ge on an ion trap ESI instrument led to the desired characterisation. Copyr ight (C) 2001 John Wiley & Sons, Ltd.