A HIGH-RESOLUTION DUAL MASS GATE FOR ION SEPARATION IN LASER DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY/

A dual mass gate is described which allows for high resolution separat ion of ions under realistic laser desorption/ionization and matrix ass isted laser desorption/ionization time of flight mass spectrometry con ditions at 10 kV kinetic energy. The device consists of two interleave d comb units sequentially positioned in the ion beam path. This allows significant improvement in resolution relative to one unit by separat ion of ''low pass'' and ''high pass'' functions. Principal limits as g iven by mechanical dimensions of the device and electrical properties of the switches are also discussed. (C) 1998 American Institute of Phy sics.