Radiant energy – Ionic separation or analysis – Methods
Patent
1986-07-07
1988-03-29
Anderson, Bruce C.
Radiant energy
Ionic separation or analysis
Methods
250288, 250423P, B01D 5944
Patent
active
047345799
ABSTRACT:
An ultrasensitive mass spectrometry method based on multiphoton sub-Doppler resonance ionization 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. Background species are separately ionized and rejected. 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. Isotopic spectrum analysis of the ions is performed by the spectrometer and the ions are then detected by a detector 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. Further improved sensitivity is achieved by: (1) using a frequency offset of the laser frequency in an amount proportional to the laser intensity to overcome AC Stark shifts, and (2) withdrawing ions for mass separation from only the central portion of the laser interaction volume.
REFERENCES:
patent: 3941670 (1976-03-01), Pratt
patent: 4020350 (1977-04-01), Ducas
patent: 4115078 (1978-09-01), Jammer et al.
patent: 4156144 (1979-05-01), Pike et al.
patent: 4166219 (1979-08-01), Ausschmitt
patent: 4336230 (1982-06-01), Bethe et al.
patent: 4442354 (1984-04-01), Hurst et al.
patent: 4636287 (1987-01-01), Pike et al.
"Laser Spectroscopy for Sensitive Detection", Whitaker et al., Proceedings of SPIE, vol. 286, Apr. 23-24, 1981.
Clark Charles W.
Lucatorto Thomas B.
Whitaker Tom J.
Anderson Bruce C.
Atom Sciences, Inc.
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