METHOD OF ANALYZING IONS IN AN APPARATUS INCLUDING A TIME OF FLIGHT MASS SPECTROMETER AND A LINEAR ION TRAP

摘要

A method of analyzing ions is carried out in a mass spectrometer apparatuscomprising an ion source, a linear RF quadrupole and a time of flight massspectrometer. Ions are generated from the ion source and passed into thelinear RF quadrupole. To retain ions within the linear RF quadrupole,potentials are applied to either end of it and it is then operated as an iontrap. Ions of interest are selected in the linear RF quadrupole and unwantedions are caused to be ejected. Selected ions are then excited and caused tocollide with a neutral gas, to cause collision induced dissociation thereof,thereby forming fragment ions for analysis in the time of flight massspectrometer. The potential of one end of the linear RF quadrupole is thenadjusted to pass selected and fragment ions through to the time of flight massspectrometer. This enables a spectrum of the selected and the fragment ions tobe obtained from the time of flight mass spectrometer.