Method of space charge control in an ion trap mass spectrometer
US5479012A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 10, 1994 |
| Grant date | Dec 26, 1995 |
| Priority date | — |
| Expiry date | Jan 10, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/424
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of using a quadrupole ion trap mass spectrometer for high resolution mass spectroscopy is disclose. In the preferred embodiment, the space charge in the ion trap is controlled with high accuracy. The mass spectrum to be analyzed is divided into a plurality of contiguous mass segments and each of the segments is separately scanned. To control space charge, a broadband supplemental waveform is applied to the ion trap during the ionization period for each segment, the broadband signal being construct to eliminate all unwanted ions from the ion trap by resonance ejection such that only those ions having masses within the desired mass segment remain in the ion trap. Preferably, the ionization of each mass segment is performed under identical trapping conditions, and the ionization parameters for each segment is adjusted to optimize the space charge in the trap for that particular segment. Conveniently, the adjustment of ionization parameters may be based on the previous analytical scan of the same mass segment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.