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US 8,410,430 B2Granted
Mass spectrometer
AssigneeMicromass UK Limited
InventorsDaniel James Kenny, Jason Lee Wildgoose
Life of this patent
Estimating the term…
Abstract
A Time of Flight mass analyser is disclosed wherein the time period between successive orthogonal acceleration pulses is less than the time of flight of ions having the maximum mass to charge ratio of interest. As a result, some ions are subject to wrap-around and will appear in a subsequent mass spectrum. Mass spectra obtained at two different sampling rates may be compared and mass peaks relating to ions which have and have not been subject to wrap-around may be identified.
Claims15
A method of mass spectrometry comprising:
- providing a Time of Flight mass analyser comprising an orthogonal acceleration electrode and a drift or time of flight region;
- repeatedly energising said orthogonal acceleration electrode so as to repeatedly orthogonally accelerate packets of ions into said drift or time of flight region, wherein the periodicity of energising said orthogonal acceleration electrode or the time period between successive energisations of said orthogonal acceleration electrode is less than the time of flight of ions having the maximum mass to charge ratio within said packets of ions which are orthogonally accelerated into said drift or time of flight region;
- orthogonally accelerating packets of ions into said drift or time of flight region with a first periodicity or wherein a first time period Δt1 is maintained between successive energisations of said orthogonal acceleration electrode;
- and obtaining first time of flight or mass spectral data;
- orthogonally accelerating packets of ions into said drift or time of flight region with a second periodicity or wherein a second different time period Δt2 is maintained between successive energisations of said orthogonal acceleration electrode;
- and obtaining second time of flight or mass spectral data;
- comparing said first time of flight or mass spectral data with said second time of flight or mass spectral data;
- and
- identifying as non-wrapped data, time of flight or mass spectral peaks which have substantially the same time of flight, mass or mass to charge ratio and/or substantially the same intensity in said first time of flight or mass spectral data as in said second time of flight or mass spectral data.
6 more elements
A Time of Flight mass analyser comprising an orthogonal acceleration electrode and a drift or time of flight region;
- and
- control means arranged and adapted to repeatedly energise said orthogonal acceleration electrode so as to repeatedly orthogonally accelerate packets of ions into said drift or time of flight region, wherein the periodicity of energising said orthogonal acceleration electrode or the time period between successive energisations of said orthogonal acceleration electrode is less than the time of flight of ions having the maximum mass to charge ratio within said packets which are orthogonally accelerated into said drift or time of flight region;
- wherein said mass analyser:
- orthogonally accelerates packets of ions into said drift or time of flight region with a first periodicity or wherein a first time period Δt1 is maintained between successive energisations of said orthogonal acceleration electrode;
- and obtains first time of flight or mass spectral data;
- orthogonally accelerates packets of ions into said drift or time of flight region with a second periodicity or wherein a second different time period Δt2 is maintained between successive energisations of said orthogonal acceleration electrode;
- and obtains second time of flight or mass spectral data;
- compares said first time of flight or mass spectral data with said second time of flight or mass spectral data;
- and
- identifies as non-wrapped data, time of flight or mass spectral peaks which have substantially the same time of flight, mass or mass to charge ratio and/or substantially the same intensity in said first time of flight or mass spectral data as in said second time of flight or mass spectral data.
7 more elements
Dependencies are inferred from the claim text.