Patent ID: 6541766
Filing Date: 2003-04-01
Classification: H01J

Abstract:
A method of mass spectrometry using an ion trap mass spectrometer, said ion trap mass spectrometer including: a filament for emitting electrons; a ring electrode and a pair of end cap electrodes for forming an ion trap region; a first electron gate electrode and a second electron gate electrode provided between said filament and one of the end cap electrodes; and a detector for detecting an ion ejected from said ion trap region, said method of mass spectrometry comprising:ionizing a sample, the ionizing step comprising applying a positive voltage to said first electron gate electrode and said second electron gate electrode to inject electrons from the filament into said ion trap region; and analyzing mass of the ionized sample, the analyzing step comprising: applying a negative voltage to said first electron gate electrode, applying a positive voltage to said second electron gate electrode, and scanning a high frequency voltage applied to said ring electrode, whereby ions in said ion trap region are consecutively ejected and then detected.