PROLONGED ION RESONANCE COLLISION INDUCED DISSOCIATION IN A QUADRUPOLE ION TRAP

摘要

A technique is disclosed for conducting collision induced dissociation (CID) in a quadrupole ion trap (QIT) having higher order field components. In order to compensate for the shift in the frequency of motion with amplitude of the excited ions arising from the influence of higher-order field components, the amplitude of the RF voltages applied to the QIT is monotonically varied during the excitation period to prolong the condition of resonance, resulting in higher average kinetic energies of the excited ions. Thus, higher fragmentation efficiencies may be obtained, or a targeted level of fragmentation may be achieved in less time relative to conventional CID.