Method and apparatus for analyzing a substance using MSn analysis
US6992285B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2000 |
| Grant date | Jan 31, 2006 |
| Priority date | — |
| Expiry date | Aug 24, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/0063
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of and apparatus for analyzing a substance takes a stream of ions in said substance and supplies the ions to a collision cell including a quadrupole rod set for guiding the ions and a buffer gas. An RF voltage is applied to the quadrupole rod set to guide ions. An additional alternating current signal is applied to the quadrupole rod set at a frequency selected to cause resonance excitation of the secular frequency of a desired ion, whereby said desired ions are excited and undergo collision with the buffer gas causing fragmentation. The alternating current signal is then modulated, whereby periods in which said alternating current signal is applied alternate with periods in which said alternating signal is not applied. The ion spectrum after fragmentation is collected to generate one set of data for one spectrum, representative of the ion spectrum when the alternating current signal is applied, and another set of data for another spectrum, representative of the ion spectrum when the alternating current signal is not applied. These two spectra can then be subtracted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.