| 摘要 |
Ions that are transported from an ion source to a mass spectrometer for m ass analysis are often accompanied by background particles such as photons, neutral species, and cluster or aerosol ions, which originate in the ion sou rce. Background particles are also produced by scattering and neutralization of ions during collisions with background gas molecules in higher pressure regions with line-of-sight to the mass spectrometer detector In either case, such background particles produce noise in mass spectra Apparatus and metho ds are provided in which a multipole ion guide is configured to efficiently transport ions through multiple vacuum stages, while preventing background p articles, produced both in the ion source and along the ion transport pathwa y, from reaching the detector, thereby improving signal-to-noise in mass spe ctra. |
