Abstract: A mass or mass to charge ratio selective ion trap is disclosed which directs ions into a small ejection region. A RF voltage acts to confine ions in a first (y) direction within the ion trap. A DC or RF voltage acts to confine ions in a second (x) direction. A quadratic DC potential well acts to confine ions in a third (z) direction within the ion trap. The profile of the quadratic DC potential well progressively varies along the second (x) direction.

Abstract: A method of mass spectrometry is disclosed comprising digitising a first signal output from an ion detector to produce a first digitised signal, detecting one or more peaks in the first digitised signal and determining a first area S0 or a first intensity I0 of the one or more peaks and a first arrival time T0 of the one or more peaks thereby forming a first list of data pairs and determining whether or not the first area S0 or the first intensity I0 exceeds a first threshold area Smax or a first threshold intensity Imax. The first threshold area Smax and the first threshold intensity Imax correspond respectively to a peak area and a peak intensity indicative of substantially simultaneous arrival of two ions which the ion detector is unable to resolve.

Abstract: A method of introducing and ejecting ions from an ion entry/exit device (4) is disclosed. The ion entry/exit device (4) has at least two arrays of electrodes (20,22). The device is operated in a first mode wherein DC potentials are successively applied to successive electrodes of at least one of the electrode arrays ((20,22) in a first direction such that a potential barrier moves along the at least one array in the first direction and drives ions into and/or out of the device in the first direction. The device is also operated in a second mode, wherein DC potentials are successively applied to successive electrodes of at least one of the electrode arrays (20,22) in a second, different direction such that a potential barrier moves along the array in the second direction and drives ions into and/or out of the device in the second direction. The device provides a single, relatively simple device for manipulating ions in multiple directions.

Abstract: A mass analyzer is disclosed comprising an annular ion guide comprising a first annular ion guide section and a second annular ion guide section, wherein the annular ion guide comprises: (i) an inner cylindrical electrode arrangement which is axially segmented and comprises a plurality of first electrodes and (ii) an outer cylindrical electrode arrangement which is axially segmented and comprises a plurality of second electrodes. Ions are introduced into the first annular ion guide section so that the ions form substantially stable circular orbits. Ions are orthogonally accelerated from the first annular ion guide section into the second annular ion guide section and one or more parabolic DC potentials are maintained along a portion of the second annular ion guide section so that ions undergo simple harmonic motion. An inductive ion detector is arranged and adapted to detect ions within the second annular ion guide section.

Abstract: A mass spectrometer is disclosed comprising a RF ion guide wherein in a mode of operation a continuous, quasi-continuous or pulsed beam of ions is orthogonally sampled from the ion guide and wherein the continuous, quasi-continuous or pulsed beam of ions is not axially trapped or otherwise axially confined within the RF ion guide. The ion guide is maintained, in use, at a pressure selected from the group consisting of: (i) 0.0001-0.001 mbar; (ii) 0.001-0.01 mbar; (iii) 0.01-0.1 mbar; (iv) 0.1-1 mbar; (v) 1-10 mbar; (vi) 10-100 mbar; and (vii) >100 mbar.

Abstract: A method is disclosed comprising: trapping ions in an ion trap (40); applying a first force on the ions within the ion trap in a first direction, said force having a magnitude that is dependent upon the value of a physicochemical property of the ions; applying a second force on these ions in the opposite direction so that the ions separate according to the physicochemical property value as a result of the first and second forces; and then pulsing or driving ions out of one or more regions of the ion trap.

Abstract: A method of introducing and ejecting ions from an ion entry/exit device is disclosed. The ion entry/exit device has at least two arrays of electrodes. The device is operated in a first mode wherein DC potentials are successively applied to successive electrodes of at least one of the electrode arrays in a first direction such that a potential barrier moves along the at least one array in the first direction and drives ions into and/or out of the device in the first direction. The device is also operated in a second mode, wherein DC potentials are successively applied to successive electrodes of at least one of the electrode arrays in a second, different direction such that a potential barrier moves along the array in the second direction and drives ions into and/or out of the device in the second direction.

Abstract: A Time of Flight mass analyzer is disclosed comprising an annular ion guide having a longitudinal axis and comprising a first annular ion guide section and a second annular ion guide section. Ions are introduced into the first annular ion guide section so that the ions form substantially stable circular orbits within the first annular ion guide section about the longitudinal axis. An ion detector is disposed within the annular ion guide. Ions are orthogonally accelerated in a first axial direction from the first annular ion guide section into the second annular ion guide section. An axial DC potential is maintained along at least a portion of the second annular ion guide section so that the ions are reflected in a second axial direction which is substantially opposed to the first axial direction. The ions undergo multiple axial passes through the second annular ion guide section before being detected by the ion detector.

Abstract: A method of separating ions according to mass to charge ratio is disclosed. The method comprises: providing a separation device comprising a plurality of electrodes; applying one or more transient DC voltages or potentials to at least some of said electrodes in order to urge ions in a first direction through said separation device; and providing a gas flow in a second direction which is substantially inclined or opposed to said first direction. The opposed gas flow unexpectedly improves the mass to charge ratio separation resolution of the device.

Abstract: A mass spectrometer is disclosed comprising a first mass filter comprising a plurality of electrodes and a first device arranged and adapted to generate an axial force which drives at least some ions axially through or along the first mass filter and a quadrupole mass filter or mass analyzer arranged downstream of the mass filter.

Abstract: A Time of Flight mass analyser is disclosed comprising an annular ion guide having a longitudinal axis and comprising a first annular ion guide section and a second annular ion guide section. Ions are introduced into the first annular ion guide section so that the ions form substantially stable circular orbits within the first annular ion guide section about the longitudinal axis. An ion detector is disposed within the annular ion guide. Ions are orthogonally accelerated in a first axial direction from the first annular ion guide section into the second annular ion guide section. An axial DC potential is maintained along at least a portion of the second annular ion guide section so that the ions are reflected in a second axial direction which is substantially opposed to the first axial direction. The ions undergo multiple axial passes through the second annular ion guide section before being detected by the ion detector.

Abstract: A non-linear ion guide is disclosed comprising a plurality of electrodes. An ion guiding region is arranged between the electrodes, and the ion guiding region curves at least in a first direction. A DC voltage is applied to at least some of the electrodes in order to form a DC potential well which acts to confine ions within the ion guiding region in the first direction.

Abstract: An ion trapping system is disclosed comprising an ion urging system for urging ions to spread out within an ion trapping region. Alternatively, the ion trapping system may deflect ions such that ions enter the ion trapping region at different locations. Alternatively, an ion deflector may be arranged upstream of, or at the entrance to, the ion trapping region, for deflecting ions such that ions enter the ion trapping region with different speeds so that the ions spread out within the ion trapping region.

Abstract: A method of Fourier transform ion mobility spectrometry is disclosed wherein an absorption spectrum of the complex spectral data is used to determine the ion mobilities of ions.

Abstract: A method of analyzing ions is disclosed comprising: (i) separating ions according to a physico-chemical property in a separator; (ii) transmitting ions which emerge from the separator through a transfer device with a first transit time t1, energizing a pusher electrode or orthogonal acceleration electrode and obtaining first data; (iii) transmitting ions which subsequently emerge from the separator through the transfer device with a second greater transit time t2, energizing the pusher electrode or orthogonal acceleration electrode and obtaining second data; and (iv) repeating steps (ii) and (iii) one or more times. The pusher electrode or orthogonal acceleration electrode is energized with a period t3, wherein t2?t1 is arranged to equal t3/2. The first and second data are combined to form a composite data set.

Abstract: A Time of Flight mass analyzer is disclosed comprising an annular ion guide having a longitudinal axis and comprising a first annular ion guide section and a second annular ion guide section. Ions are introduced into the first annular ion guide section so that the ions form substantially stable circular orbits within the first annular ion guide section about the longitudinal axis. An ion detector is disposed within the annular ion guide. Ions are orthogonally accelerated in a first axial direction from the first annular ion guide section into the second annular ion guide section. An axial DC potential is maintained along at least a portion of the second annular ion guide section so that the ions are reflected in a second axial direction which is substantially opposed to the first axial direction. The ions undergo multiple axial passes through the second annular ion guide section before being detected by the ion detector.

Abstract: A Time of Flight mass analyzer is disclosed comprising an annular ion guide having a longitudinal axis and comprising a first annular ion guide section and a second annular ion guide section. Ions are introduced into the first annular ion guide section so that the ions form substantially stable circular orbits within the first annular ion guide section about the longitudinal axis. The ions are then orthogonally accelerated ions from the first annular ion guide section into the second annular ion guide section. An ion detector is disposed within the annular ion guide and has an ion detecting surface arranged in a plane which is substantially perpendicular to the longitudinal axis.

Abstract: A mass spectrometer is disclosed comprising a first device, a second device and a switch arranged and adapted: (i) to direct ions at a first time T1 to the first device and to substantially prevent ions from entering the second device; and (ii) to direct ions at a second later time T2 to the second device and to substantially prevent ions from entering the first device. At the first time T1 the second device may not be in an operational state to potentially optimally fragment, react, mass filter or otherwise process ions since the second device may be in a process of equilibration, changing state, re-filling, recharging, transition, replenishing, switching voltage or altering an operational parameter.

Abstract: A method of mass spectrometry is disclosed comprising digitising a first signal output from an ion detector to produce a first digitised signal, detecting one or more peaks in the first digitised signal and determining a first area S0 or a first intensity I0 of the one or more peaks and a first arrival time T0 of the one or more peaks thereby forming a first list of data pairs and determining whether or not the first area S0 or the first intensity I0 exceeds a first threshold area Smax or a first threshold intensity Imax. The first threshold area Smax and the first threshold intensity Imax correspond respectively to a peak area and a peak intensity indicative of substantially simultaneous arrival of two ions which the ion detector is unable to resolve.

Abstract: A method of mass spectrometry is disclosed comprising separating ions temporally in a first device and analysing the mass or mass to charge ratio of the ions or of product or fragment ions derived from the ions in a mass or mass to charge ratio analyser disposed downstream of the first device. The method further comprises obtaining a first set of drift times for the ions through the first device by measuring ion arrival times and determining the transit time of the ions and/or of the product or fragment ions through one or more intermediate regions or devices disposed between the first device and the mass to charge ratio analyser. The method further comprises obtaining a second set of drift times for the ions through the first device by correcting the first set of drift times to account for the determined transit times.