Simultaneous detection isotopic ratio mass spectrometer
US6297501A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 1999 |
| Grant date | Oct 2, 2001 |
| Priority date | — |
| Expiry date | Apr 19, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention comprises a mass spectrometer 1 and a method of mass spectrometry that is especially useful for the measurement of the isotopic composition of hydrogen in the presence of a helium carrier gas. Interference to the accurate measurement of the small HD.sup.+ peak at mass-to-charge ratio 3 by the much larger He.sup.+ peak at mass-to-charge ratio 4 is reduced by provision of an energy filter 35 in the ion detector assembly used to collect HD.sup.+ ions. This prevents ions of He.sup.+ which have lost energy through scattering, etc giving rise to a signal from the HD.sup.+ detector and distorting the deuterium hydrogen isotopic ratio measurement. Such a mass spectrometer 1 is typically used in conjunction with a continuous flow inlet system 4 based on an elemental analyzer that converts hydrogen present in a sample to gaseous hydrogen in a flow of helium carrier gas. Another embodiment of the invention provides a similar mass spectrometer useful for carbon or oxygen isotopic determinations in carbon dioxide gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.