Reducing interferences, in plasma source mass spectrometers
US5514868A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 14, 1995 |
| Grant date | May 7, 1996 |
| Priority date | — |
| Expiry date | Mar 14, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/482
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for determining the elemental composition of a sample (1) by plasma mass spectroscopy comprises introducing a said sample (1) into an inductively-coupled or microwave-induced plasma formed in an inert gas to generate atomic ions from the elements present in it; passing at least some of said atomic ions through a nozzle-skimmer interface (15-21) into an evacuated chamber (23), said interface comprising electrode means (19, 39) for determining the electrical potential at which said atomic ions enter said evacuated chamber (23) so that atomic ions of a given mass-to-charge ratio enter said chamber with a particular kinetic energy; energy filtering (40) the ions entering said chamber to prevent at least molecular ions of approximately said given mass-to-charge ratio having kinetic energies less than said particular kinetic energy from passing through; and mass filtering (22) the ions passed by the energy filter and detecting those of said ions having said given mass-to-charge ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.