US3984692A
Expired / Lapsed
US
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Ionization apparatus and method for mass spectrometry
Assignee: Individual
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Filing: 1972-01-04
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Granted: 1976-10-05
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Expires: 1992-01-04
Abstract
Abstract Ionizing gaseous substances (e.g., for mass spectral analysis) by passing the neutral gaseous substances sequentially through a chemical ionization (CI) zone and an electron impact ionization (EI) zone and impelling gaseous ions formed in one or both of the zones to a mass spectrometer. CI, EI, simultaneous EI--EI, and closely alternating CI and EI spectra are obtainable.
Inventors
- 👤 Guy P. Arsenault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:50
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/02; H01J49/10; H01J49/14; H01J49/147; H01J49/145
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
152 words
Apparatus for ionizing substances, comprising a reactant gas and a substance to be analyzed, for analysis in a mass spectrometer comprising: a first ionization zone constructed to contain said gaseous substances therein at a chemical ionization pressure and comprising first ionizing means for ionizing said substance to be analyzed in said zone; a second separate ionization zone constructed to contain said gaseous substances therein at an electron-impact ionization pressure below the pressure in said first ionization zone and comprising second ionizing means comprising a source of electrons for ionizing said substance to be analyzed in said second ionization zone; an aperture between said first and second ionization zones sufficiently small to provide a pressure drop between said zones; flow directing means for directing neutral gaseous substances in a path sequentially through said first and second ionization zones; and means for directing and impelling ionized substances in a path to said mass spectrometer.
Claim 2
Dependent Claim
152 words
Apparatus for ionizing substances, comprising a reactant gas and a substance to be analyzed, for analysis in a mass spectrometer comprising: a first ionization zone constructed to contain said gaseous substances therein at a chemical ionization pressure and comprising first ionizing means for ionizing said substance to be analyzed in said zone; a second separate ionization zone constructed to contain said gaseous substances therein at an electron-impact ionization pressure below the pressure in said first ionization zone and comprising second ionizing means comprising a source of electrons for ionizing said substance to be analyzed in said second ionization zone; an aperture between said first and second ionization zones sufficiently small to provide a pressure drop between said zones; flow directing means for directing neutral gaseous substances in a path sequentially through said first and second ionization zones; and means for directing and impelling ionized substances in a path to said mass spectrometer.
Claim 3
Dependent Claim
25 words
Apparatus according to claim 1 for analyzing the gaseous effluent of a gas chromatograph including conduit means between said chromatograph and said first ionization zone.
Claim 4
Dependent Claim
41 words
Apparatus according to claim 1 including a second aperture for said gaseous substances between said second ionization zone and said mass spectrometer, wherein said second aperture is larger than said aperture between said first ionization zone and said second ionization zone.
Claim 5
Dependent Claim
40 words
Apparatus according to claim 1 wherein said means for directing and impelling said ionized substances to said mass spectrometer comprises sources of electrical potential selected to provide a potential impelling said ions from said ionization zones to said mass spectrometer.
Claim 6
Dependent Claim
51 words
Apparatus according to claim 4 wherein said sources of electrical potential include potential sources providing a greater impelling potential for said ion at said first ionization zone than at said second ionization zone to impel ions from said first zone into said second zone on the path to said mass spectrometer.
Claim 7
Dependent Claim
70 words
Apparatus according to claim 5 including an additional potential source between said zones, said additional source providing a greater impelling potential than the potential at either of said zones, and of sufficiently greater impelling potential than the impelling potential at said first zone to impel ions formed in said first zone from said first zone past said additional potential source into said second zone on their path towards mass spectrometer.
Claim 8
Dependent Claim
26 words
Apparatus according to claim 6 wherein said additional source is an electroconductive ion-permeable screen arranged in the path between said first zone and said second zone.
Claim 9
Dependent Claim
67 words
Apparatus according to claim 6 including a second additional potential source between said second ionization zone and the ground plate of said mass spectrometer, said second additional potential source being of greater impelling potential than the potential source at said second ionization zone and the potential source at the ground plate of said mass spectrometer to impel ions from said second ionization zone to said mass spectrometer.
Claim 10
Dependent Claim
29 words
Apparatus according to claim 8 wherein said second additional potential source is an electroconductive ion-permeable screen arranged in the path between said second ionization zone and said mass spectrometer.
Claim 11
Dependent Claim
44 words
Apparatus according to claim 5 wherein said ionized substances are positive ions, and the potential at said second ionization zone is negative with respect to the potential at said first ionization zone to impel said ions from said first zone to said second zone.
Claim 12
Dependent Claim
22 words
Apparatus according to claim 1 wherein said mass spectrometer is of the type having a quadrupole mass filter for separating ions therein.
Claim 13
Dependent Claim
19 words
Apparatus according to claim 1 wherein said ionizing means at said first ionization zone comprises a source of electrons.
Claim 14
Dependent Claim
57 words
Apparatus according to claim 1 wherein said second ionization zone comprises a gaseous substance entrance substantially aligned with the exit from said first ionization zone, and a gaseous substance exit substantially aligned with the entrance to said second ionization zone, the electron source for said second ionization zone being located midway between said entrance and said exit.
Claim 15
Dependent Claim
55 words
Apparatus according to claim 1 further including switching means for selectively energizing only said first ionizing means, only said second ionizing means, or both of said ionizing means to ionize said substance to be analyzed only in said first ionization zone, only in said second ionization zone, or in both of said ionization zones, respectively.
Claim 16
Dependent Claim
16 words
Apparatus according to claim 1 wherein said chemical ionization pressure is at least 10.sup. -1 Torr.
Claim 17
Independent Claim
78 words
A method for analyzing a gaseous substance comprising the steps of: chemically ionizing said substance in a chemical ionization zone at a chemical ionization pressure; passing the product of said chemical ionization zone into an electron-impact ionization zone maintained at an electron-impact ionization pressure through an aperture sufficiently small to maintain a pressure drop between said zones; subjecting said product to electron-impact ionization in said electron-impact ionization zone; and obtaining the mass spectrum of the ionized substances formed.
Claim 18
Independent Claim
78 words
A method for analyzing a gaseous substance comprising the steps of: chemically ionizing said substance in a chemical ionization zone at a chemical ionization pressure; passing the product of said chemical ionization zone into an electron-impact ionization zone maintained at an electron-impact ionization pressure through an aperture sufficiently small to maintain a pressure drop between said zones; subjecting said product to electron-impact ionization in said electron-impact ionization zone; and obtaining the mass spectrum of the ionized substances formed.
Claim 19
Dependent Claim
60 words
The method of claim 16 comprising alternately obtaining a first mass spectra of ionized substances formed in said chemical ionization zone and a second mass spectra of ionized substances formed in said electron-impact ionization zone by alternately energizing said zones, wherein said first spectra and said second spectra are both obtained with a total elapsed time of about 30 second.
Claim 20
Dependent Claim
58 words
A method according to claim 17 including the previous steps of separating said gaseous substance into components in a gas chromatograph and passing the effluent containing said components from said chromatograph to said chemical ionization zone, and wherein said two mass spectra are both obtained within the time width at half-height of a peak component of said effluent.
Claim 21
Dependent Claim
43 words
A method according to claim 16 including the steps of energizing both of said ionization zones during passage therethrough of said gaseous substance so as to obtain a mass spectrum simultaneously indicative both of chemical ionization and of electron-impact ionization of said substance.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-05 | 1980-04-05 | 1980-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-05 | 1984-04-05 | 1984-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-05 | 1988-04-05 | 1988-10-05 | $7700.00 | Window Closed / Lapsed |