Ion focusing lensing system for a mass spectrometer interfaced to an atmospheric pressure ion source

摘要

This invention describes an ion focusing lensing system and method interfaced between an atmospheric pressure ion source and a mass spectrometer in which the proper positioning of an electrostatic lens within a transition flow pressure region may be used to increase the transmission efficiency of ions to the mass spectrometer. The described configuration allows an increase in ion transmission efficiency to be gained in a manner independent from the operational voltages in the viscous flow pressure region, thereby allowing independent adjustment of the desired degree of collisionally induced dissociation and declustering processes. In addition, proper placement of the electrostatic lens in the transition flow region allows for collimation of the ion beam, enhancing ion beam transmission into the mass spectrometer aperture.