| 摘要 |
<p>Inside a first-stage intermediate vacuum chamber (6) of an atmospheric-pressure ionization mass-spectrograph apparatus, cluster ions that are the cause of background noise are generated mainly at area (A), and fragment ions are generated mainly at area (B). Accordingly, in cases of in-source CID analysis mode, a DC voltage that is lower than that of a skimmer (8) is applied to a first ion guide (7), so that an accelerating electric field is generated at area (B). This enables sufficient energy to be given to the ions, to facilitate fragmentation. In cases when in-Source CID analysis is not conducted, a DC voltage that is lower than that of the first ion guide (7) is applied to the exit end (3b) of a desolvation tube (3), so that no electric field is generated at area (B) and an accelerating electric field is generated only at area (A). This enables inhibition of generation of both the cluster ions and the fragment ions, and attainment of a high-quality chromatogram.</p> |
