摘要:
An ion guide is disclosed wherein an axial DC voltage barrier is created at the exit of the ion guide. A primary RF voltage is applied to the electrodes in order to confine ions radially within the ion guide. A supplemental RF voltage is also applied to the electrodes. The supplemental RF voltage has a greater axial repeat length than that of the primary RF voltage. The amplitude of the supplemental RF voltage is increased with time causing ions to become unstable and gain sufficient axial kinetic energy such that the ions overcome the axial DC voltage barrier. Ions emerge axially from the ion guide in mass to charge ratio order.
摘要:
An ion guide is disclosed wherein an axial DC voltage barrier is created at the exit of the ion guide. A primary RF voltage is applied to the electrodes in order to confine ions radially within the ion guide. A supplemental RF voltage is also applied to the electrodes. The supplemental RF voltage has a greater axial repeat length than that of the primary RF voltage. The amplitude of the supplemental RF voltage is increased with time causing ions to become unstable and gain sufficient axial kinetic energy such that the ions overcome the axial DC voltage barrier. Ions emerge axially from the ion guide in mass to charge ratio order.
摘要:
A mass spectrometer is disclosed comprising a quadrupole rod set ion trap (2, 3) wherein a potential field is created at the exit of the ion trap (4, 5) which decreases with increasing radius in one radial direction. Ions within the ion trap (2, 3) are mass selectively excited in a radial direction. Ions which have been excited in the radial direction experience a potential field which no longer confines the ions axially within the ion trap but which instead acts to extract the ions and hence causes the ions to be ejected axially from the ion trap (2, 3).
摘要:
A mass spectrometer is disclosed comprising a quadrupole rod set ion trap wherein a potential field is created at the exit of the ion trap which decreases with increasing radius in one radial direction. Ions within the ion trap are mass selectively excited in a radial direction. Ions which have been excited in the radial direction experience a potential field which no longer confines the ions axially within the ion trap but which instead acts to extract the ions and hence causes the ions to be ejected axially from the ion trap.
摘要:
A linear ion trap (6,7,8)is disclosed comprising a central quadrupole rod set (6)and a post-filter quadrupole rod set (8). A 180° phase difference is maintained between axially adjacent rod electrodes of the central quadrupole rod set (6) and the post-filter quadrupole (8) so that an axial pseudo-potential barrier is created between the central quadrupole rod set (6) and the post-filter quadrupole (8). A supplementary AC voltage is applied to the rods of the central quadrupole (6) in order to radially excite ions which are desired to be ejected from the ion trap. The ions are ejected from the ion trap (6,7,8) non-adiabatically in an axial direction.
摘要:
A linear ion trap (6, 7, 8)is disclosed comprising a central quadrupole rod set (6)and a post-filter quadrupole rod set (8). A 180° phase difference is maintained between axially adjacent rod electrodes of the central quadrupole rod set (6) and the post-filter quadrupole (8) so that an axial pseudo-potential barrier is created between the central quadrupole rod set (6) and the post-filter quadrupole (8). A supplementary AC voltage is applied to the rods of the central quadrupole (6) in order to radially excite ions which are desired to be ejected from the ion trap. The ions are ejected from the ion trap (6, 7, 8) non-adiabatically in an axial direction.
摘要:
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.
摘要:
Ions having a restricted range of mass to charge ratios are transmitted to the acceleration region of a Time of Flight mass analyzer. A control system applies a first extraction pulse to an acceleration electrode in order to accelerate a first group of ions into the time of flight region at a first time T1, wherein ions having the lowest mass to charge ratio in the first group of ions have a time of flight ΔT1min through the time of flight region and ions having the highest mass to charge ratio in the first group of ions have a time of flight ΔT1max through the time of flight region. The control system applies a second extraction pulse to the acceleration electrode at a subsequent second time T2, wherein ΔT1max−ΔT1min≦T2−T1
摘要:
An ion inlet for a mass spectrometer is disclosed comprising a housing having a sampling orifice and an atmospheric pressure orifice. One or more gas outlets are provided in the housing. Gas is drawn through the sampling orifice by a pump so that the gas exits via the one or more gas outlets.
摘要:
A mass spectrometer is disclosed comprising an orthogonal acceleration Time of Flight mass analyser. A pulse or packet of ions is released either from an ion trap (7) or alternatively from a travelling wave ion guide arranged upstream of an orthogonal acceleration electrode (2) which forms part of the Time of Flight mass analyser. Ions in the pulse or packet of ions which is released become temporally dispersed and the orthogonal acceleration electrode (2) is energised multiple times prior the release of a subsequent pulse or packet of ions.