EP0202943A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of operating an ion trap
Assignee: Thermo Finnigan LLC
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Filing: 1986-05-22
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Granted: —
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Expires: 2006-05-22
Abstract
Abstract The scanning method includes applying a supplementary AC field to eject out of the trap volume those of the ions with particular mass-to-charge ratios. The intensity of the trapping field is then changed. The trapping field is a three-dimensional quadruple field. Ions are infected within the trap volume so that those within the predetermined range are trapped. The field is controlled and the trapped ions are dissociated into fragments so that those within a desired range of mass-to-charge ratio remain trapped within the volume and then later are made to escape for analysis and detection.
Inventors
- 👤 John E.P. Syka
- 👤 John Nathan Louris
- 👤 Paul E. Kelley
- 👤 George C. Stafford
- 👤 Walter E. Reynolds
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 17:28
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/26; H01J49/34; H01J49/42; H01J49/4205; H01J49/424; H01J49/004; H01J49/0045; H01J49/0063; H01J49/0081; H01J49/426; H01J49/427; H01J49/429
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
55 words
A method of scanning ions within a predetermined range of mass-to-charge ratio trapped within a trap volume with a trapping field, characterised by the steps of applying a supplementary AC field to eject out of said trap volume those of said ions with particular mass-to-charge ratios and thereafter changing the intensity of said trapping field.
Claim 2
Independent Claim
55 words
A method of scanning ions within a predetermined range of mass-to-charge ratio trapped within a trap volume with a trapping field, characterised by the steps of applying a supplementary AC field to eject out of said trap volume those of said ions with particular mass-to-charge ratios and thereafter changing the intensity of said trapping field.
Claim 3
Dependent Claim
18 words
A method as claimed in Claim 1, characterised in that said trapping field is a three-dimensional quadrupole field.
Claim 4
Independent Claim
110 words
A method of operating an ion trap for mass analyzing a sample, comprising the steps of defining a trap volume with a three-dimensional quadrupole field adapted to trap ions within a predermined range of mass-to-charge ratio; and forming or injecting ions within said trap volume such that those within said predetermined range are trapped within said trap volume; characterised by the steps of controlling said quadrupole field and dissociating said trapped ions into fragments such that those of said ions and said fragments within a desired range of mass-to-charge ratio remain trapped within said trap volume and then later are made to escape said trap volume for analysis and detection.
Claim 5
Independent Claim
110 words
A method of operating an ion trap for mass analyzing a sample, comprising the steps of defining a trap volume with a three-dimensional quadrupole field adapted to trap ions within a predermined range of mass-to-charge ratio; and forming or injecting ions within said trap volume such that those within said predetermined range are trapped within said trap volume; characterised by the steps of controlling said quadrupole field and dissociating said trapped ions into fragments such that those of said ions and said fragments within a desired range of mass-to-charge ratio remain trapped within said trap volume and then later are made to escape said trap volume for analysis and detection.
Claim 6
Dependent Claim
70 words
A method as claimed in Claim 3, characterised in that said quadrupole field is generated by an ion trap having a ring electrode and spaced end electrodes, said quadrupole field being defined by the amplitude (U) of a direct current voltage between said end electrodes and said ring electrode, the magnitude (V) of an RF voltage applied between said ring electrodes, and W = 2πx frequency of said RF voltage.
Claim 7
Dependent Claim
30 words
S. A method as claimed in Claim 4, characterised in that said step of controlling said quadrupole field is effected by changing one or more of U, V and W.
Claim 8
Dependent Claim
15 words
A method as claimed in Claim 5, characterised in that U is changed to 0.
Claim 9
Independent Claim
45 words
A method as claimed in any one of Claims 3 to 6, characterised in that said step of forming ions is effected by gating a burst of electrons into said trap volume and causing ions not within said predetermined range to leave said trap volume.
Claim 10
Independent Claim
23 words
A method as claimed in any one of Claims 3 to 7, characterised by the step of pumping energy into said trapped ions.
Claim 11
Independent Claim
27 words
A method as claimed in any one of Claims 3 to 8, characterised by the step of causing said trapped ions to collide with energetic background particles.
Claim 12
Independent Claim
36 words
A method as claimed in any one of Claims 3 to 9, characterised in that said step of controlling said quadrupole field and dissociating said trapped ions includes the step of superposing a supplementary AC field.
Claim 13
Dependent Claim
27 words
A method as claimed in Claim 1 or Claim 10, characterised in that said supplementary field is,turned on while the intensity of said quadrupole field is fixed.
Claim 14
Dependent Claim
28 words
A method as claimed in Claim 1 or Claim 1C, characterised in that said supplementary field is turned on while the intensity of said quadrupole field is varied.
Claim 15
Dependent Claim
30 words
A method as claimed in Claim 1 or Claim 10, characterised in that the frequency of said supplementary field is varied while the voltage of said quadrupole field is fixed.
Claim 16
Dependent Claim
35 words
A method as claimed in Claim 1 or any one of Claims 9 to 11, characterised in that the frequency of said supplementary field is at or near resonance of one of said trapped ions.
Claim 17
Dependent Claim
49 words
A method as claimed in Claim 10, characterised in that said quadrupole field and said supplementary field are controlled such that during a first period one of said trapped ions is in resonance and that during a subsequent second period a fragment of said one ion is in resonance.
References Cited (Backward Citations)
No citation records indexed.
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