US4882484A
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Method of mass analyzing a sample by use of a quistor
Assignee: Teledyne CME
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Filing: 1988-10-31
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Granted: 1989-11-21
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Expires: 2008-10-31
Abstract
Abstract In a quadrupole ion store (QUISTOR), a sample is analyzed by increasing themplitude of the harmonic, or "secular", oscillations of selected stably trapped ions so that they leave the trapping field. In a preferred embodiment, deviations from the ideal electrode geometry are incorporated into the QUISTOR to produce resonance phenomena between the r and z secular oscillations, thereby increasing the amplitude of oscillations in the z direction.
Inventors
- 👤 Jochen Franzen
- 👤 Reemt-Holger Gabling
- 👤 Gerhard Heinen
- 👤 Gerhard Weiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:38
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/26; H01J49/34; H01J49/42; H01J49/4205; H01J49/424; H01J49/426; H01J49/427; H01J49/429
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
138 words
The method of mass analyzing a sample which comprises the steps of: defining a three-dimensional electrical quadrupole storage field in which sample ions over the entire mass range of interest can be simultaneously trapped; introducing or creating sample ions into the quadrupole field whereby ions within the mass range of interest are simultaneously trapped and perform ion-mass specific secular movements; superimposing an exciting RF field with a frequency different from that of the storage RF field; changing the superimposed fields so that simultaneously and stably trapped ions of consecutive masses encounter a resonance of their secular movements with the exciting RF field, take up energy, increase thereby the secular movement amplitudes, and leave the trapping field; detecting the ions of sequential masses as they leave the trapping field; and providing an output signal indicative of the ion mass.
Claim 2
Independent Claim
138 words
The method of mass analyzing a sample which comprises the steps of: defining a three-dimensional electrical quadrupole storage field in which sample ions over the entire mass range of interest can be simultaneously trapped; introducing or creating sample ions into the quadrupole field whereby ions within the mass range of interest are simultaneously trapped and perform ion-mass specific secular movements; superimposing an exciting RF field with a frequency different from that of the storage RF field; changing the superimposed fields so that simultaneously and stably trapped ions of consecutive masses encounter a resonance of their secular movements with the exciting RF field, take up energy, increase thereby the secular movement amplitudes, and leave the trapping field; detecting the ions of sequential masses as they leave the trapping field; and providing an output signal indicative of the ion mass.
Claim 3
Dependent Claim
129 words
The method of claim 1 in which the storage field is generated by a QUISTOR of the type having a ring electrode and spaced end electrodes where the storage field is defined by U, V stor , and f stor , and the exciting field is defined by V exc and f exc , and in which the superimposed fields are changed by one or more of U, V stor , f stor , or f exc , where: U=amplitude of DC voltage between the ring electrode and the end electrodes V stor =magnitude of storage RF voltage between ring electrode and end electrodes f stor =frequency of RF voltage V exc =magnitude of exciting RF voltage between the two end electrodes f exc =frequency of exciting RF voltage.
Claim 4
Dependent Claim
19 words
The method of claim 2 in which f exc is set constant, and essentially only V stor is changed.
Claim 5
Dependent Claim
50 words
The method of claim 3 in which the constant frequency f exc of the exciting field matches a sum or coupling resonance frequency arising from geometrical deviations of the storing field from the angle, 1:1.414 of the asymptotes, or from electrical deviations of the RF voltage from ideal sine waves.
Claim 6
Dependent Claim
51 words
The method of claim 4 in which said sum or coupling resonances of the secular movements of the ions are generated by geometrical deviations of the storing field introduced by deviations of the shape of the ring and end electrodes from the ideal hyperbolic form with angle 1:1.414 of the asymptotes.
Claim 7
Dependent Claim
98 words
The method of claim 5 in which the radii of the curved end electrodes and of the curved ring electrode, both defined in the points nearest to the field center, in order to generate the resonances of the secular movements obey the condition ##EQU3## R e =radius of the end electrodes in the points nearest to the field center R r =radius of the ring electrode in the points nearest to the field center r o =smallest distance of the ring electrode from the field center z O =smallest distance of the end electrodes from the field center.
Claim 8
Dependent Claim
44 words
The method of claim 5 in which the radii of the curved end electrodes and of the curved ring electrode, both defined in the points nearest to the field center, in order to generate the resonances of the secular movements obey the condition 4.010<Q<25.0.
Claim 9
Dependent Claim
71 words
A method as in claim 4 in which the shape of the QUISTOR electrodes are chosen so that the coupling resonance frequency of the secular ion movements coincides with a low fraction 1/n (n=small integer number greater then 2) of the storage frequency, and in which the excitation voltage with frequency f exc =f stor /n is coupled in frequency and phase to the storage voltage with frequency f stor .
Claim 10
Dependent Claim
9 words
A method as in claim 8 in which n=3.
Claim 11
Dependent Claim
56 words
A method as in claim 1 in which the scanning speed for the parameters of the superimposed fields is chosen such that the shift of the secular frequency with increasing amplitude, caused by an anharmonic storage field, is at least partially compensated by an inverse shift of the secular frequency caused by the parameter scanning itself.
References Cited (Backward Citations)
US4540884A
Cited
US4749860A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-20 | 1993-05-22 | 1993-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-20 | 1997-05-22 | 1997-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-20 | 2001-05-22 | 2001-11-21 | $7700.00 | Window Closed / Lapsed |