PULSED AXIAL ACTIVATION IN THE ION TRAP - A NEW METHOD FOR PERFORMING TANDEM MASS-SPECTROSCOPY (MS/MS)

A short DC voltage pulse is applied to one endcap of a quadrupole ion-trap mass spectrometer to activate trapped ions. High internal-energy deposition is achieved as evidenced by 91+/92+ peak ratios in excess of 20 for dissociation of the n-butylbenzene molecular ion.1 The amount of internal energy can be controlled directly by varying the amplitude of the pulse. Dissociation efficiencies are less than those typically observed for collision-induced dissociation in the ion trap and range from 50% at low internal energy deposition to 5% at maximum internal energy deposition.