Patent EP0113207A2 successfully refreshed from Google Patents.
EP0113207A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of mass analyzing a sample by use of a quadrupole ion trap
Assignee: Thermo Finnigan LLC
•
Filing: 1983-12-07
•
Granted: —
•
Expires: 2003-12-07
Abstract
Abstract In a quadrupole ion store or ion trap type mass spectrometer, significantly improved mass selection is achieved by scanning the applied RF and DC voltages or the frequency ω sequentially to render unstable trapped ions. These are passed out through apertures in an end cap to a high gain electron multiplier to provide a signal indicative of the ion mass. Sensitivity and mass resolution is also enhanced by operating the ion tape at a relatively high pressure in the range 1 X 10 -1 to 1 X 10 -5 torr. The presence of collision gas molecules, such as helium, improves sensitivity and mass resolution. In addition, the structure itself is built of stacked units, sealed by 0-rings, which are easily disassembled for cleaning.
Inventors
- 👤 George Caterine Stafford
- 👤 Paul Edwin Kelley
- 👤 David Russel Stephens
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 21:05
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: 24
Claim 1
Independent Claim
98 words
The method of mass analyzing a sample which comprises the steps of: (a) defining a three dimensional quadrupole field in which sample ions over the entire mass range of interest can be simultaneously trapped; (b) introducing or creating sample ions into the quadrupole field whereby ions within the range of interest are trapped; (c) changing the three dimensional trapping field so trapped ions of consecutive specific masses become sequentially unstable and leave the trapping field; (d) detecting the sequential unstable ions as they leave the trapping field; and (e) providing an output signal indicative of the ion mass.
Claim 2
Independent Claim
98 words
The method of mass analyzing a sample which comprises the steps of: (a) defining a three dimensional quadrupole field in which sample ions over the entire mass range of interest can be simultaneously trapped; (b) introducing or creating sample ions into the quadrupole field whereby ions within the range of interest are trapped; (c) changing the three dimensional trapping field so trapped ions of consecutive specific masses become sequentially unstable and leave the trapping field; (d) detecting the sequential unstable ions as they leave the trapping field; and (e) providing an output signal indicative of the ion mass.
Claim 3
Dependent Claim
73 words
The method as in Claim 1 in which the field is generated by an ion trap of the type having a ring electrode and spaced end electrodes where the field is defined by U, V and w where U = amplitude of direct current voltage between the end electrodes and ring electrode V = magnitude of RF voltage applied between ring electrodes ω = 2 n f f = frequency of RF voltage
Claim 4
Dependent Claim
26 words
The method of Claim 2 in which the three dimensional quadrupole trapping field is changed by changing any one or more of U, V and w.
Claim 5
Dependent Claim
19 words
The method of Claim 2 in which the three dimensional quadrupole trapping field is changed by linearly increasing V.
Claim 6
Dependent Claim
23 words
The method of Claim 2 in which the three dimensional quadrupole trapping field is changed by linearly changing U and V in proportion.
Claim 7
Dependent Claim
22 words
The method of Claim 1 in which the sample is introduced into the trapping field and then ionized by electron impact ionization.
Claim 8
Dependent Claim
21 words
The method of Claim 1 in which the sample is introduced into the trapping field and there ionized by chemical ionization.
Claim 9
Independent Claim
133 words
The method of mass analyzing a sample which comprises the steps of: (a) ionizing the sample to form ions indicative of the sample constituents; (b) temporarily trapping said ions in an ion storage apparatus of the type having two end caps and a ring by applying voltage U + V sin wt across the ring and end caps to provide a substantially quadrupole electric field; (c) scanning one or more of U, V and w between predetermined limits so that the ions of specific mass become sequentially and selectively unstable and sequentially exit from the ion trap; and (d) detecting the unstable ions as they exit the ion trap to provide an indication of the ions as a function of U, V and w applied to thereby identify the mass of the ions.
Claim 10
Independent Claim
133 words
The method of mass analyzing a sample which comprises the steps of: (a) ionizing the sample to form ions indicative of the sample constituents; (b) temporarily trapping said ions in an ion storage apparatus of the type having two end caps and a ring by applying voltage U + V sin wt across the ring and end caps to provide a substantially quadrupole electric field; (c) scanning one or more of U, V and w between predetermined limits so that the ions of specific mass become sequentially and selectively unstable and sequentially exit from the ion trap; and (d) detecting the unstable ions as they exit the ion trap to provide an indication of the ions as a function of U, V and w applied to thereby identify the mass of the ions.
Claim 11
Dependent Claim
16 words
The method of Claim 8 wherein U is set to zero and only V is scanned.
Claim 12
Dependent Claim
10 words
The method of Claim 8 wherein only U is scanned.
Claim 13
Dependent Claim
11 words
The method of Claim 8 wherein U and V are scanned.
Claim 14
Dependent Claim
23 words
A method as in Claim 8 including the step improving the sensitivity and mass resolution by providing a collision gas in said field.
Claim 15
Dependent Claim
39 words
13-. A method as in Claim 12 where said improving step includes introducing said sample into said storage apparatus along with collision gas molecules and allowing said gas molecules to collide with sample ions in the ion storage region.
Claim 16
Dependent Claim
32 words
A method as in Claim 12 where the ion storage region is maintained at a collision gas pressure in the range of 1 X 10 1 to 1 X 10 -5 torr.
Claim 17
Dependent Claim
13 words
A method as in Claim 13 where said collision gas molecules are helium.
Claim 18
Dependent Claim
15 words
A method as in Claim 13 where said collision gas molecules are Xenon or argon.
Claim 19
Independent Claim
67 words
A method of mass analyzing a sample comprising the steps of: (a) ionizing the sample to form ions indicative of the sample constituents; (b) temporarily trapping said ions in a three dimensional quadrupole field; (c) improving the mass resolution and sensitivity of said analysis of trapped ion by introduction of collision gas; and (d) selecting ion masses of different values by scanning the three dimensional quadrupole field.
Claim 20
Independent Claim
67 words
A method of mass analyzing a sample comprising the steps of: (a) ionizing the sample to form ions indicative of the sample constituents; (b) temporarily trapping said ions in a three dimensional quadrupole field; (c) improving the mass resolution and sensitivity of said analysis of trapped ion by introduction of collision gas; and (d) selecting ion masses of different values by scanning the three dimensional quadrupole field.
Claim 21
Independent Claim
225 words
A method of mass analyzing a sample which comprises the steps of: applying RF and d.c. voltages V + U sin wt between the ring electrode and the end cap electrodes of an ion trap electrode structure to impose in the region interior to said electrode structure a potential distribution approximating a three dimensional quadrupole field which is described in the cartesian coordinate system by the equation where φ = the electric potential relative to the electric potential at the origin (x = 0, y = 0, Z = 0) V' = a magnitude describing RF component of the electric potential field ω = 2 π f f = frequency of ratio frequency component of the electric potential field U = a magnitude describing the d.c. component of the electric potential field r 0 = characteristic dimension of the potential field and which has ion trapping characteristics defined by the parameters S a and S G where and introducing ions into said three dimensional quadrupole field region and trapping said ions; changing S q so that the range of ion specific masses (m/e) stable in the field changes causing trapped ions to become unstable and exit the trapping field in sequence of said ions specific masses (m/e); detecting the unstable ions; and providing a signal indicative of the m/e ratio as the ions become unstable.
Claim 22
Independent Claim
225 words
A method of mass analyzing a sample which comprises the steps of: applying RF and d.c. voltages V + U sin wt between the ring electrode and the end cap electrodes of an ion trap electrode structure to impose in the region interior to said electrode structure a potential distribution approximating a three dimensional quadrupole field which is described in the cartesian coordinate system by the equation where φ = the electric potential relative to the electric potential at the origin (x = 0, y = 0, Z = 0) V' = a magnitude describing RF component of the electric potential field ω = 2 π f f = frequency of ratio frequency component of the electric potential field U = a magnitude describing the d.c. component of the electric potential field r 0 = characteristic dimension of the potential field and which has ion trapping characteristics defined by the parameters S a and S G where and introducing ions into said three dimensional quadrupole field region and trapping said ions; changing S q so that the range of ion specific masses (m/e) stable in the field changes causing trapped ions to become unstable and exit the trapping field in sequence of said ions specific masses (m/e); detecting the unstable ions; and providing a signal indicative of the m/e ratio as the ions become unstable.
Claim 23
Dependent Claim
15 words
The method as in Claim 18 where S a is changed instead of S .
Claim 24
Dependent Claim
16 words
The method as in Claim 18 in which S and S are a q changed simultaneously.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.