Methods and apparatus for mass spectrometry
US6586727B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2001 |
| Grant date | Jul 1, 2003 |
| Priority date | — |
| Expiry date | Jul 12, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/4215
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved method of parent ion scanning is disclosed. In one embodiment a quadrupole mass filter 3 upstream of a collision cell 4 is arranged to operate in a highpass mode. Parent ions transmitted by the mass filter 3 are fragmented in the collision cell 4 and detected by an orthogonal time of flight analyser 5 which obtains a daughter ion mass spectrum. Ions having a mass to charge ratio below the cutoff of the mass filter 3 are identified as daughter ions, and candidate parent ions may then be discovered and their identity confirmed by obtaining corresponding daughter ion spectra. In a second embodiment, the collision cell 4 alternates between high and low fragmentation and candidate parent ions can additionally be identified on the basis of the loss of a predetermined ion or neutral particle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.