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 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.
摘要:
An ion guide or mass analyser (2) is disclosed comprising a plurality of electrodes (2a) having apertures through which ions are transmitted in use. A pseudo-potential barrier is created at the exit of the ion guide or mass analyser (2). The amplitude or depth of the pseudo-potential barrier is inversely proportional to the mass to charge ratio of an ion. One or more transient DC voltages (4) are applied to the electrodes (2a) of the ion guide or mass analyser (2) in order to urge ions along the length of the ion guides or mass analyser (2). The amplitude of the transient DC voltage (4) applied to the electrode (2a) may be increased with time so that ions are caused to be emitted from the ion guide or mass analyser (2) in reverse order of their mass to charge ratio.
摘要:
A collision or fragmentation cell is disclosed comprising a plurality of electrodes wherein a first RF voltage is applied to an upstream group of electrodes and a second different RF voltage is applied to a downstream group of electrodes. The radial confinement of parent ions entering the collision or fragmentation cell is optimized by the first RF voltage applied to the upstream group of electrodes and the radial confinement of daughter or fragment ions produced within the collision or fragmentation cell is optimized by the second different RF voltage applied to the downstream group of electrodes.
摘要:
An ion guide or mass analyser is disclosed comprising a plurality of electrodes having apertures through which ions are transmitted in use. A pseudo-potential barrier is created at the exit of the ion guide or mass analyser. The amplitude or depth of the pseudo-potential barrier is inversely proportional to the mass to charge ratio of an ion. One or more transient DC voltages are applied to the electrodes of the ion guide or mass analyser in order to urge ions along the length of the ion guides or mass analyser. The amplitude of the transient DC voltage applied to the electrode may be increased with time so that ions are caused to be emitted from the ion guide or mass analyser in reverse order of their mass to charge ratio.
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 or alternatively from a travelling wave ion guide arranged upstream of an orthogonal acceleration electrode which forms part of the Time of Flight mass analyser. Ions in the pulse or packet or ions which is released become temporally dispersed and the orthogonal acceleration electrode is energized multiple times prior the release of a subsequent pulse or packet of ions.
摘要:
An ion guide or mass analyser is disclosed comprising a plurality of electrodes having apertures through which ions are transmitted in use. A pseudo-potential barrier is created at the exit of the ion guide or mass analyser. The amplitude or depth of the pseudo-potential barrier is inversely proportional to the mass to charge ratio of an ion. One or more transient DC voltages are applied to the electrodes of the ion guide or mass analyser in order to urge ions along the length of the ion guides or mass analyser. The amplitude of the transient DC voltage applied to the electrode may be increased with time so that ions are caused to be emitted from the ion guide or mass analyser in reverse order of their mass to charge ratio.