Method for selective collisional dissociation using border effect excitation with prior cooling time control

摘要

A variable cooling time is imposed on ions in a quadrupole ion trap prior to excitation through border effect operation. Continuous variation of the cooling time brings about continuous variation of the selected ion internal energy when subjected to the boundary effect such that the boundary effect competes more favorably with ion loss in the trap, and fragmentation reaction channels having successively greater energies of activation can be accessed preferentially.