TuP-18
FRAGMENTATION OF SMALL OLIGONUCLEOTIDE ANIONS FORMED BY ELECTROSPRAY
Allan Weimann, Paula Iannitti and Margaret M. Sheil
Department of Chemistry, University of Wollongong, NSW 2522
The collision-induced fragmentation of small oligonucleotide anions (4-10 mers) formed by electrospray has been investigated. In the mass spectrometer used for this study - a VG AutoSpec OA TOF mass spectrometer equipped with an electrospray ion source - it is possible to alter the charge state of the oligonucleotides by adjusting the sampling cone and the skimmer lens voltages. For 4- and 6-mers the fragmentation of all the different charge states has been investigated and compared. Some general trends governing fragmentation will be discussed. The effect of different collision energies and different pressures in the collision cell has also been studied. Finally in order to determine the optimum conditions for generating so-called "sequence ions" the ease of fragmentation of the different charge states will be described by comparing the fragmentation at identical pressures and collision energies.