Patent ID: 7064320
Filing Date: 2006-06-20
Classification: G01N,H01J

Abstract:
1. A mass spectrometer comprising: an atmospheric pressure chemical ionization (APCI) source including: (a1) a first ionization portion including a needle electrode to which a voltage for corona discharge is applied, and an exhaust aperture for said primary ion generation gas, for generating a primary ion from said primary ion generation gas by discharge of said needle electrode; (a2) a primary ion introduction aperture through which said primary ion flows; and (a3) a second ionization portion including an introduction aperture of said primary ion generation gas, for generating a sample ion of a sample gas by the reaction between said primary ion introduced from said primary ion introduction aperture and said sample gas introduced from an end of a column of gas chromatography, said second ionization portion having the end of said column arranged therein; (b) a sample ion movement aperture through which said sample ion moves; and (c) a mass analysis portion for conducting mass analysis of said sample ion; wherein: said exhaust aperture is arranged at a portion on the opposite side to the tip end of said needle electrode, said primary ion generation gas introduced into said second ionization portion is caused to flow to said exhaust aperture from the distal end of said needle electrode through said primary ion introduction aperture, and the end of said column is arranged at a position satisfying the relation r≦2R where R is a radius of an inner diameter of said primary ion introduction aperture and r is a distance between an axis connecting the center of said primary ion introduction aperture and the center of said sample ion movement aperture, and end of said column.