摘要:
A mass spectrometer is disclosed comprising an ion mobility spectrometer (8) and an ion gate (9). A collision cell (10) is arranged downstream of the ion gate (9). The operation of the ion mobility spectrometer (8) and the ion gate (9) are synchronised so that only ions having a particular mass to charge ratio and a desired charge state are onwardly transmitted to the collision cell (10).
摘要:
A mass spectrometer is disclosed comprising an ion mobility spectrometer or separator (3) arranged upstream of a collision or fragmentation cell (5). Ions are separated according to their ion mobility within the ion mobility spectrometer or separator (3). The kinetic energy of the ions exiting the ion mobility spectrometer or separator (3) is increased substantially linearly with time in order to optimize the fragmentation energy of ions as they enter the collision or fragmentation cell (5).
摘要:
A closed-loop ion guide (1) is disclosed comprising a plurality of electrodes having apertures through which ions are transmitted in use. Ions are injected into the closed-loop ion guide (1) and may make several circuits of the closed-loop ion guide (1) before being ejected from the ion guide (1). In a mode of operation the ion guide (1) may be arranged to separate ions temporally according to their ion mobility.
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 mass spectrometer is disclosed wherein an ion signal is split into a first and second signal. The first and second signals are multiplied by different gains and are digitised. Arrival time and intensity pairs are calculated for both digitised signals and the resulting time and intensity pairs are combined to form a high dynamic range spectrum. The spectrum is then combined with other corresponding spectra to form a summed spectrum.
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 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 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.