Laser Photoionization in an Ion Trap Mass Spectrometer

The use of three dimensional quadrupole electrodynamic traps for conventional mass spectrometry and for MS/MS experiments has become popular since their commercial introduction by Finnigan. The development of the mass selective instability mode of scanning these devices to generate a mass spectrum is largely responsible for their popularity. This mode of operation allows ions with a broad range of m/e values to be stored in the trap. Ions can then be sequentially ejected from the trap (from low to high m/e) as the RF voltage is increased. The ejected ions are detected with high sensitivity by an electron multiplier.