Ultrasensitive method for measuring isotope abundance ratios
US4634864A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1983 |
| Grant date | Jan 6, 1987 |
| Priority date | — |
| Expiry date | Oct 27, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D59/44
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An ultrasensitive mass spectrometry method based on multiphoton sub-Doppler resonance ionization is used to measure abundance sensitivities. The method preferentially ionizes a selected isotope in a sample by using Doppler-free resonant multiphoton ionization to produce an enhanced ratio of selected isotopes. As necessary or desired, selected isotope ions are preferentially ionized by using a second Doppler-free resonant multiphoton ionization to provide an additional isotope enhancement. The ions produced are injected into a mass spectrometer (24). Isotopic spectrum analysis of the ions is performed by the spectrometer (24) and the ions are then detected by a detector (26) such as a particular photon multiplier capable of observing a single ion. In one embodiment, at least one of the steps of preferentially ionizing the selected isotope is accomplished by two counter propagating laser beams of slightly different frequencies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.