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US 7,095,015 B2Granted
Mass spectrometer
AssigneeMicromass UK Limited
InventorsRobert Harold Bateman, Martin Green
Life of this patent
Estimating the term…
Abstract
A mass spectrometer is disclosed wherein the pusher electrode of a Time of Flight mass analyser is operated in conjunction with an ion gate to ensure that low mass background or matrix ions are not injected into the drift region of the mass analyser.
Claims51
A mass spectrometer comprising:
- an ion source;
- an orthogonal acceleration Time of Flight mass analyser comprising an electrode for orthogonally accelerating ions, an ion detector and a drift region therebetween;
- an ion gate upstream of said electrode;
- and
- control means for switching said ion gate between a first mode and a second mode, said second mode having a lower ion transmission efficiency than said first mode, wherein in a mode of operation said control means:
- (i) switches said ion gate from said first mode to said second mode at a time T1;
- and
- (ii) causes said electrode to inject or orthogonally accelerate ions into said drift region at a later time T1+ΔT1;
- wherein ΔT1 is set such that ions having a mass to charge ratio ≦ a value M1 are not substantially injected or orthogonally accelerated into said drift region by said electrode.
6 more elements
A mass spectrometer comprising:
- an ion source;
- an orthogonal acceleration Time of Flight mass analyser comprising an electrode for orthogonally accelerating ions, an ion detector and a drift region therebetween;
- an ion gate upstream of said electrode;
- and
- control means for switching said ion gate between a first mode and a second mode, said second mode having a lower ion transmission efficiency than said first mode, wherein in a mode of operation said control means:
- (i) switches said ion gate from said second mode to said first mode at a time T2;
- and
- (ii) causes said electrode to inject or orthogonally accelerate ions into said drift region at a later time T2+ΔT2;
- wherein ΔT2 is set such that ions having a mass to charge ratio ≧ a value M3 are not substantially injected or orthogonally accelerated into said drift region by said electrode.
6 more elements
A mass spectrometer comprising:
- an ion source;
- an orthogonal acceleration Time of Flight mass analyser comprising an electrode for orthogonally accelerating ions, an ion detector and a drift region therebetween;
- an ion gate upstream of said electrode;
- and
- control means for switching said ion gate between a first mode and a second mode, said second mode having a lower ion transmission efficiency than said first mode, wherein in a mode of operation said control means:
- (i) switches said ion gate from said second mode to said first mode at a time T3;
- (ii) switches said ion gate from said first mode to said second mode at a later time T3+δT3;
- and
- (iii) causes said electrode to inject or orthogonally accelerate ions into said drift region at a yet later time T3+δT3+ΔT3;
- wherein δT3 and ΔT3 are set such that ions having a mass to charge ratio ≦ a value M1 are not substantially injected or orthogonally accelerated into said drift region by said electrode and such that ions having a mass to charge ratio ≧ a value M3 are not substantially injected or orthogonally accelerated into said drift region by said electrode, wherein M1<M3.
7 more elements
A mass spectrometer comprising:
- an ion source;
- an orthogonal acceleration Time of Flight mass analyser comprising an electrode for orthogonally accelerating ions, an ion detector and a drift region therebetween;
- an ion gate upstream of said electrode;
- and
- control means for switching said ion gate between a first mode and a second mode, said second mode having a lower ion transmission efficiency than said first mode, wherein in a mode of operation said control means:
- (i) switches said ion gate from said first mode to said second mode at a time T4;
- (ii) switches said ion gate from said second mode to said first mode at a later time T4+δT4;
- and
- (iii) causes said electrode to inject or orthogonally accelerate ions into said drift region at a yet later time T4+δT4+ΔT4;
- wherein δT4 and ΔT4 are set such that ions having a mass to charge ratio equal to a value M2 are not substantially injected or orthogonally accelerated into said drift region by said electrode.
7 more elements
A mass spectrometer comprising:
- an ion source;
- an orthogonal acceleration Time of Flight mass analyser comprising an electrode for orthogonally accelerating ions, an ion detector and a drift region therebetween;
- an ion gate upstream of said electrode;
- and
- control means for switching said ion gate between a first mode and a second mode, said second mode having a lower ion transmission efficiency than said first mode, wherein in a mode of operation said control means:
- (i) switches said ion gate from said first mode to said second mode at a time T4;
- (ii) switches said ion gate from said second mode to said first mode at a later time T4+δT4;
- and
- (iii) causes said electrode to inject or orthogonally accelerate ions into said drift region at a yet later time T4+δT4+ΔT4;
- wherein δT4 and ΔT4 are set such that ions having a mass to charge ratio in a range M1′-M3′ are not substantially injected or orthogonally accelerated into said drift region by said electrode, wherein M1′<M3′.
7 more elements
A method of mass spectrometry, comprising:
- switching an ion gate from a first mode to a second mode at a tune T1, said second mode having a lower ion transmission efficiency than said first mode;
- and
- injecting or orthogonally accelerating ions into a drift region of an orthogonal acceleration Time of Flight mass analyser at a later time T1+ΔT1;
- wherein ΔT1 is set such that ions having a mass to charge ratio ≦ a value M1 are not substantially injected or orthogonally accelerated into said drift region.
1 more element
A method of mass spectrometry, comprising:
- switching an ion gate from a second mode to a first mode at a time T2, said second mode having a lower ion transmission efficiency than said first mode;
- and injecting or orthogonally accelerating ions into a drift region of an orthogonal acceleration Time of Flight mass analyser at a later time T2+ΔT2;
- wherein ΔT2 is set such that ions having a mass to charge ratio ≧ a value M3 are not substantially injected or orthogonally accelerated into said drift region.
A method of mass spectrometry, comprising:
- switching an ion gate from a second mode to a first mode at a time T3, said second mode having a lower ion transmission efficiency than said first mode;
- switching said ion gate from said first mode to said second mode at a later time T3+δT3;
- and
- injecting or orthogonally accelerating ions into a drift region of an orthogonal acceleration Time of Flight mass analyser at a yet later time T3+δT3+ΔT3;
- wherein δT3 and ΔT3 are set such that ions having a mass to charge ratio ≦ a value M1 are not substantially injected or orthogonally accelerated into said drift region and such that ions having a mass to charge ratio ≧ a value M3 are not substantially injected or orthogonally accelerated into said drift region, wherein M1<M3.
2 more elements
A method of mass spectrometry, comprising:
- switching an ion gate from a first mode to a second mode at a time T4, said second mode having a lower ion transmission efficiency than said first mode;
- switching said ion gate from said second mode to said first mode at a later time T4+δT4;
- and
- injecting or orthogonally accelerating ions into a drift region of an orthogonal acceleration Time of Flight mass analyser at a yet later time T4+δT4+ΔT4;
- wherein δT4 and ΔT4 are set such that ions having a mass to charge ratio equal to a value M2 are not substantially injected or orthogonally accelerated into said drift region.
2 more elements
A method of mass spectrometry, comprising:
- switching an ion gate from a first mode to a second mode at a time T4, said second mode having a lower ion transmission efficiency than said first mode;
- switching said ion gate from said second mode to said first mode at a later time T4+δT4;
- and
- injecting or orthogonally accelerating ions into a drift region of an orthogonal acceleration Time of Flight mass analyser at a yet later time T4+δT4+ΔT4;
- wherein δT4 and ΔT4 are set such that ions having a mass to charge ratio in a range M1′-M3′ are not substantially injected or orthogonally accelerated into said drift region, wherein M1′<M3′.
2 more elements
Dependencies are inferred from the claim text.