Method and apparatus for isolating ions in an ion trap with increased resolving power
US5696376A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1996 |
| Grant date | Dec 9, 1997 |
| Priority date | — |
| Expiry date | May 20, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/427
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of operation of an ion trap mass spectrometer which isolates a first group of ions having a mass-to-charge ratio range is disclosed. The method includes producing ions from a plurality of atoms or molecules; trapping the ions in an ion trap by applying a trapping voltage to a ring electrode; applying an excitation voltage to a pair of end-cap electrodes; employing as the excitation voltage a first broadband excitation waveform and a second broadband excitation waveform, with the first waveform exciting the ions excluding substantially all of the first group and also excluding substantially all of a second group of ions having a range of mass-to-charge ratios about the first group's mass-to-charge ratio range, and the second waveform exciting the second group; applying the first waveform in order to eject the ions excluding substantially all of the first and second groups; and applying the second waveform in order to successively eject the second group of ions, according to the mass-to-charge ratios thereof, excluding substantially all of the first group of ions, thereby isolating the first group of ions. In another embodiment, the excitation voltage is a broadband excitati…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.