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:
A collision or fragmentation cell (4) is disclosed comprising a plurality of electrodes wherein a first RF voltage (7a) is applied to an upstream group of electrodes and a second different RF voltage (7b) is applied to a downstream group of electrodes. The radial confinement of parent ions entering the collision or fragmentation cell (4) is optimised 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 (4) is optimised by the second different RF voltage applied to the downstream group of electrodes.
摘要:
A mass spectrometer is disclosed comprising a Time of Flight mass analyzer comprising an ion detector comprising an Analog to Digital Converter. Signals from the Analog to Digital Converter are digitized and the arrival time and intensity of ions are determined. The arrival time T0 and intensity S0 of each ion arrival event is converted into two separate intensities S(n),S(n+i) which are stored in neighboring time bins T(n), T(n+1).
摘要:
A Time of Flight mass analyser is disclosed comprising an ion detector comprising an Analogue to Digital Converter. Output signals from the ion detector are digitised and the arrival times and intensity values relating to ion arrival events are determined. If the determined arrival times from two signals fall within the same time window then the arrival times are added together in a weighted manner and the intensity values are combined.
摘要:
A Time of Flight mass analyser is disclosed comprising an ion detector comprising an Analogue to Digital Converter. Output signals from the ion detector are digitised and the arrival times and intensity values relating to ion arrival events are determined. If the determined arrival times from two signals fall within the same time window then the arrival times are added together in a weighted manner and the intensity values are combined.
摘要:
A mass spectrometer is disclosed comprising a Time of Flight mass analyser comprising an ion detector comprising an Analogue to Digital Converter. Signals from the Analogue to Digital Converter are digitised and the arrival time and intensity of ions are determined. The arrival time T0 and intensity S0 of each ion arrival event is converted into two separate intensities S(n),S(n+i) which are stored in neighbouring time bins T(n), T(n+1).
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:
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 a quadrupole rod set ion guide or mass filter device (6). A broadband frequency signal (10) having one or more notches (11a, 11b, 11c) is applied to the rods of the quadrupole rod set (6). The notched broadband frequency signal (10) causes undesired ions to be resonantly ejected from the ion guide (6). The notched broadband frequency signal (10) has frequency components missing which correspond with the resonance frequency of ions which are desired to be onwardly transmitted. The ion guide or mass filter device (6) enables a plurality of desired ions having different mass to charge ratios to be simultaneously transmitted by the ion guide or mass filter device (6) whilst other ions are resonantly ejected from the ion guide or mass filter device (6).
摘要:
A mass spectrometer is disclosed comprising a quadrupole rod set ion guide or mass filter device (6). A broadband frequency signal (10) having one or more notches (11a, 11b, 11c) is applied to the rods of the quadrupole rod set (6). The notched broadband frequency signal (10) causes undesired ions to be resonantly ejected from the ion guide (6). The notched broadband frequency signal (10) has frequency components missing which correspond with the resonance frequency of ions which are desired to be onwardly transmitted. The ion guide or mass filter device (6) enables a plurality of desired ions having different mass to charge ratios to be simultaneously transmitted by the ion guide or mass filter device (6) whilst other ions are resonantly ejected from the ion guide or mass filter device (6).