MASS SPECTROMETER

PURPOSE:To obtain the high detection sensitivity and prevent the contamination of a mass analytical part by selectively introducing the ion of the sample component to a mass analytical part and excluding the neutral particles, in a liquid chromatography mass spectrometer consisting of the atmospheric pressure chemical ionization method. CONSTITUTION:The ion generated in an atmospheric pressure chemical ionization chamber 7 is applied with direction performance by an ion pushing-out electrode 6, and advances toward the first fine hole electrode 9. The ion beam is converged by a lens electrode 8, and passes through the electrode 9. Then, the ion passes through an ion deflecting electrode 10, and reaches the second fine hole electrode 12, and the neutral particles which have not electric charge and the transfer phase solvent collide with the inner wall of the device and the electrode 10, and fades away. The ion which pass through the electrode 12 are converged by a lens electrode 13 and mass-analyzed by a mass analytical part 14.