Laser-enhanced negative ion mass spectroscopy for weakly electron-attaching species

We report the first observation of efficient negative ion formation in exci mer-laser irradiated benzene and toluene. These negative ions were formed v ia enhanced electron attachment to highly-excited states produced by the la ser radiation. The potential of this technique as an analytical tool is dis cussed. Due to the general nature of the enhanced electron attachment mecha nism involved, this technique can be expected to be applicable for a wide v ariety of molecules. (Int J Mass Spectrom 193 (1999) 77-86) (C) 1999 Elsevi er Science B.V.