ION TRAP MASS-SPECTROMETER CAPABILITIES IN ISOMER CHARACTERIZATION .1. THE CASE OF 4,7-DIMETHOXYINDOLE, 5,6-DIMETHOXYINDOLE AND 6,7-DIMETHOXYINDOLE

The multiple MS-MS capabilities of ion trap mass spectrometry have been successfully employed in the structural characterization of isomeric 4,7-,5,6- and 6,7-dimethoxyindole. The ions arising from the sequential loss of CH3 and CO from the molecular ion have been produced by either electron impact or sequential collision experiments starting from the parent ions. Their colision specta lead on the one hand to a clear distinction between the different isomers and on the other hand to information on the different internal energies involved in the two methods. © 1990.