Use of notched broadband waveforms in a linear ion trap
US6815673B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2002 |
| Grant date | Nov 9, 2004 |
| Priority date | — |
| Expiry date | Mar 23, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/428
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for the analysis of a narrow range of fragment ions by application of a notched broadband waveform during ion accumulation within a quadrupole collision cell operated as a linear ion trap. The fragment ions are formed via the axial acceleration and collision activated dissociation of mass resolved precursor ions. A narrow band of frequencies is purposefully omitted from the spectrum, so that the secular frequency of a particular fragment ion will fall within this notch of absent frequencies and as a result will not experience resonant excitation and are retained in the linear ion trap. Simultaneously, all other ions are lost either through neutralization when they strike electrodes or through (additional) collision activated dissociation. Accordingly, a particular mass or range of masses, whose secular frequencies fall within the notch of absent frequencies in the notched broadband waveform, may be selectively accumulated during the collision activated dissociation event.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.