MULTIPLE STAGE MASS SPECTROMETER

摘要

A sensitive multiple stage (MS<n>) mass spectrometer is disclosed, capable of eliminating losses of ions during the isolation stage. One preferred instrument includes a pulsed ion source coupled with a linear array of mass selective ion trap devices, at least one trap being coupled to an external ion detector. Each ion trap is configured with a storing cell for ion trapping interspersed between a pair of guarding cells, all aligned along their z axis. AC, RF and DC voltages are applied to electrodes of the ion trap device to retain ions within the storing cells. Ions may be selectively transferred between ions traps, and selectively dissociated within each trap to enable a higher sensitivity MS<n> operation. Various ion trapping devices are disclosed: harmonic linear traps, Paul traps and quadrupole traps.