Radiant energy – Ionic separation or analysis – Methods
Patent
1998-05-04
2000-09-05
Anderson, Bruce C.
Radiant energy
Ionic separation or analysis
Methods
250292, B01D 5944, H01J 4900
Patent
active
061146919
ABSTRACT:
An RF-only quadrupole mass spectrometer in which an auxiliary RF field (dipole or quadrupole) excites selected ions at low q (typically between 0.20 and 0.89). The excited ions experience radial excursions, but many do not experience excursions sufficient to strike the rods, and are therefore transmitted and acquire increased kinetic energy in the fringing fields at the exit ends of the rods. The excited ions may therefore be selected from the non-excited ions either by their increased axial kinetic energy, or by their radial dispersion, or both, and are detected for analysis, producing sharp peaks of high sensitivity at low q, while retaining the high acceptance and other advantages of RF-only mass spectrometers. Operated in converse fashion, a high quality notch filter can be achieved. In the notch filter, an auxiliary RF field again excites ions and notches some of them out by causing them to strike the rods. Ions which are not notched out but which are nevertheless excited by the auxiliary field are discriminated against, again either by reason of their higher axial kinetic energy or their spatial dispersion or both, so that only ions on axis are detected, producing a high resolution high sensitivity notch filter.
REFERENCES:
patent: 3147445 (1964-09-01), Wuerker et al.
patent: 4090075 (1978-05-01), Brinkmann
patent: 4481415 (1984-11-01), Takeda et al.
patent: 4721854 (1988-01-01), Dawson
patent: 5089703 (1992-02-01), Schoen et al.
patent: 5187365 (1993-02-01), Kelly
patent: 5204530 (1993-04-01), Chastagner
patent: 5291017 (1994-03-01), Wang et al.
patent: 5598001 (1997-01-01), Flory et al.
patent: 5672870 (1997-09-01), Flory et al.
patent: 5998787 (1999-12-01), Hager
A.N. Hayhurst, "The operation of a quadrupole mass filter with the d.c. voltage removed when sampling ions from a source at high pressure and temperature", Aug. 15, 1995.
Raymond E. Kaiser, Jr., Extending the Mass Range of the Quadrupole Ion Trap Using Axial Modulation.
J. Throck Watson, "A technique for mass selective ion rejection in a quadrupole reaction chamber", pp. 225-235.
Anderson Bruce C.
MDS Inc.
LandOfFree
RF-only mass spectrometer with auxiliary excitation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with RF-only mass spectrometer with auxiliary excitation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and RF-only mass spectrometer with auxiliary excitation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2214679