Patent ID: 6586730
Filing Date: 2003-07-01
Classification: H01J

Abstract:
A plasma ion source mass spectrometer comprising:a sample setting portion for setting a sample; a peristaltic pump for aspirating the sample; a nebulizer for generating liquid droplets of the sample; an inductively coupled plasma torch for ionizing the sample in a plasma and for producing ions in the plasma into which the liquid droplets introduced by a nebulizing gas; an ion trap mass spectrometer for performing mass separation of the ions, wherein the ion trap mass spectrometer comprises a pair of endcap electrodes and a ring electrode disposed between the pair of endcap electrodes, an ion inlet opening for introducing the ions into the ion trap mass spectrometer is formed at one endcap electrode at an ion inlet side in a different position from a center of the one endcap electrode, and an ion outlet opening for extracting the ions separated according to mass from the ion trap mass spectrometer is formed at another endcap electrode at an ion outlet side in a center of the other endcap electrode; a gate electrode for sending the ions produced in the plasma to an ion trap mass spectrometer, wherein the gate electrode is disposed between the one endcap electrode and the inductively coupled plasma torch, and the gate electrode is provided to control a timing with which the ions are introduced into the ion trap mass spectrometer; and an ion detector for detecting the ions separated by and extracted from the ion trap mass spectrometer, wherein the ions produced in the plasma are introduced along an axis different from a central axis of the ion trap mass spectrometer, and separation of ions and photons is performed in the ion trap mass spectrometer, and the ions separated according to mass are extracted from the central axis of the ion trap mass spectrometer.