| 摘要 |
A mass spectrometer has an atmospheric pressure chemical ionization source that includes a first ionization portion (3) including a needle electrode (10), for generating a primary ion by discharge of the needle electrode a primary ion introduction aperture (14), and a second ionization portion (5) including an introduction aperture (11), for generating a sample ion by the reaction between the primary ion and the sample gas introduced from an end (12) of a column (9) of gas chromatography, a sample ion movement aperture (8); and a mass analysis portion (15); wherein the end is arranged at a position satisfying the relation r ‰¦ 2R where R is a radius of an inner diameter of the aperture (11) and r is a distance between an axis connecting the center of the aperture and the center of the aperture (8), and the end. |
