Abstract: The present invention provides a radio frequency (RF) power supply in a mass spectrometer. The power supply provides an RF signal to electrodes of a storage device to create a trapping field. The RF field is usually collapsed prior to ion ejection. In an illustrative embodiment the RF power supply includes a RF signal supply; a coil arranged to receive the signal provided by the RF signal supply and to provide an output RF signal for supply to electrodes of an ion storage device; and a shunt including a switch operative to switch between a first open position and a second closed position in which the shunt shorts the coil output.

Abstract: This invention relates to tandem mass spectrometry and, in particular, to tandem mass spectrometry using a linear ion trap and a time of flight detector to collect mass spectra to form a MS/MS experiment. The accepted standard is to store and mass analyze precursor ions in the ion trap before ejecting the ions axially to a collision cell for fragmentation before mass analysis of the fragments in the time of flight detector. This invention makes use of orthogonal ejection of ions with a narrow range of m/z values to produce a ribbon beam of ions that are injected into the collision cell. The shape of this beam and the high energy of the ions are accommodated by using a planar design of collision cell. Ions are retained in the ion trap during ejection so that successive narrow ranges may be stepped through consecutively to cover all precursor ions of interest.

Abstract: The present invention provides a radio frequency (RF) power supply in a mass spectrometer. The power supply provides an RF signal to electrodes of a storage device to create a trapping field. Such ion storage devices are often used to store ions prior to ejection to a subsequent mass analyzer. The RF field is usually collapsed prior to ion ejection. The present invention provides a RF power supply comprising: a RF signal supply, a coil arranged to receive the signal provided by the RF signal supply and to provide an output RF signal for supply to electrodes of an ion storage device, and a shunt including a switch operative to switch between a first open position and a second closed position in which the shunt including a switch operative to switch between a first open position and a second closed position in which the shunt shorts the coil output.

Abstract: This invention relates to mass spectrometers comprising a reaction cell and where mass spectra are collected both from unreacted ions and also from reaction product ions. In particular, although not exclusively, this invention finds use in tandem mass spectrometry where mass spectra are collected from precursor and fragment ions. The present invention provides an arrangement where ions may be sent to a reaction cell for fragmentation or other processing before onward transport to a mass analyser. Alternatively, ions may be passed directly to a mass analyser along a bypass path.

Abstract: This invention relates generally to multi-reflection electrostatic systems, and more particularly to improvements in and relating to the Orbitrap electrostatic ion trap. A method of operating an electrostatic ion trapping device having an array of electrodes operable to mimic a single electrode is proposed, the method comprising determining three or more different voltages that, when applied to respective electrodes of the plurality of electrodes, generate an electrostatic trapping field that approximates the field that would be generated by applying a voltage to the single electrode, and applying the three or more so determined voltages to the respective electrodes. Further improvements lie in measuring a plurality of features from peaks with different intensities from one or more collected mass spectra to derive characteristics, and using the measured characteristics to improve the voltages to be applied to the plurality of electrodes.

Abstract: This invention relates to mass spectrometry that includes ion trapping in at least one of the stages of mass analysis. In particular, although not exclusively, this invention relates to tandem mass spectrometry where precursor ions and fragment ions are analysed. A method of mass spectrometry is provided comprising the sequential steps of: accumulating in an ion store a sample of one type of ions to be analysed; accumulating in the ion store a sample of another type of ions to be analysed; and mass analysing the combined samples of the ions; wherein the method comprises accumulating the sample of the one type of ions and/or the sample of another type of ions to achieve a target number of ions based on the results of a previous measurement of the respective type of ions.

Abstract: This invention relates to a mass spectrometer including a reaction cell and to a method of using such a mass spectrometer. In particular, although not exclusively, this invention relates to a tandem mass spectrometer and to tandem mass spectrometry. The invention provides a method of mass spectrometry using a mass spectrometer having a longitudinal axis, comprising guiding ions to travel along the longitudinal axis of the mass spectrometer in a forwards direction to pass through an intermediate ion store and then to enter a reaction cell, to process the ions within the reaction cell, to eject the processed ions to travel back along the longitudinal axis to enter the intermediate ion store once more, and to eject one or more pulses of the processed ions in an off-axis direction to a mass analyser.

Abstract: This invention relates to a method of trapping ions and to an ion trapping assembly. In particular, the present invention has application in gas-assisted trapping of ions in an ion trap prior to a mass analysis of the ions in a mass spectrometer. The invention provides a method of trapping ions in a target ion trap of an ion trapping assembly that comprises a series of volumes arranged such that ions can traverse from one volume to the next, the volumes including the target ion trap, whereby ions are allowed to pass repeatedly through the volumes such that they also pass into and out from the target ion trap without being trapped. Potentials may be used to reflect the ions from respective ends of the ion trapping assembly. Optionally, a potential well and/or gas-assisted cooling may be used to cause the ions to settle in the target ion trap.

Abstract: This invention relates to tandem mass spectrometry and, in particular, to tandem mass spectrometry using a linear ion trap and a time of flight detector to collect mass spectra to form a MS/MS experiment. The accepted standard is to store and mass analyze precursor ions in the ion trap before ejecting the ions axially to a collision cell for fragmentation before mass analysis of the fragments in the time of flight detector. This invention makes use of orthogonal ejection of ions with a narrow range of m/z values to produce a ribbon beam of ions that are injected into the collision cell. The shape of this beam and the high energy of the ions are accommodated by using a planar design of collision cell. Ions are retained in the ion trap during ejection so that successive narrow ranges may be stepped through consecutively to cover all precursor ions of interest.

Abstract: This invention relates to tandem mass spectrometry and, in particular, to tandem mass spectrometry using a linear ion trap and a time of flight detector to collect mass spectra to form a MS/MS experiment. The accepted standard is to store and mass analyze precursor ions in the ion trap before ejecting the ions axially to a collision cell for fragmentation before mass analysis of the fragments in the time of flight detector. This invention makes use of orthogonal ejection of ions with a narrow range of m/z values to produce a ribbon beam of ions that are injected into the collision cell. The shape of this beam and the high energy of the ions are accommodated by using a planar design of collision cell. Ions are retained in the ion trap during ejection so that successive narrow ranges may be stepped through consecutively to cover all precursor ions of interest.

Abstract: An ion detection arrangement 140 for a time-of-flight (TOF) mass spectrometer 10 includes a beam splitter formed as a mesh 150 at the end of the TOF acceleration and detection chamber 110. Ions enter the detection arrangement through a common entrance window and are then divided by the beam splitter. Those ions striking the mesh 150 generate secondary electrons 160 which are detected by a microchannel plate forming a first detector 170. Those ions passing through the ion beam splitter are detected directly by a second detector 190 also formed from a microchannel plate. The two detectors are each connected to a corresponding data acquisition system 180, 200 and the data obtained by each are combined to generate a mass spectrum. The problems of detector saturation are thus avoided.

Abstract: This invention relates to tandem mass spectrometry and, in particular, to tandem mass spectrometry using a linear ion trap and a time of flight detector to collect mass spectra to form a MS/MS experiment. The accepted standard is to store and mass analyze precursor ions in the ion trap before ejecting the ions axially to a collision cell for fragmentation before mass analysis of the fragments in the time of flight detector. This invention makes use of orthogonal ejection of ions with a narrow range of m/z values to produce a ribbon beam of ions that are injected into the collision cell. The shape of this beam and the high energy of the ions are accommodated by using a planar design of collision cell. Ions are retained in the ion trap during ejection so that successive narrow ranges may be stepped through consecutively to cover all precursor ions of interest.

Abstract: A time-of-flight mass spectrometer, for example, a MALDI-TOF spectrometer, measures the characteristics of the charge to mass ratio of ionized particles by measuring the time taken for the particles to travel a pre-determined distance. The spectrometer comprises an accelerator (14) which accelerates the particles along at least two paths, which may be contained in a single beam of charged particles. Two detectors (26 and 30) mark the ends of the paths and are operable to detect the particles travelling therealong. The length of the path leading to the first detector (26) differs from that of the path leading to the second detector (30) to a sufficient extent to enable the difference in detection times of corresponding particles at the two detectors to be used to provide a measurement of said characteristics.

Abstract: An ion detection arrangement 140 for a time-of-flight (TOF)mass spectrometer 10 includes a beam splitter formed as a mesh 150 at the end of the TOF acceleration and detection chamber 110. Ions enter the detection arrangement through a common entrance window and are then divided by the beam splitter. Those ions striking the mesh 150 generate secondary electrons 160 which are detected by a microchannel plate forming a first detector 170. Those ions passing through the ion beam splitter are detected directly by a second detector 190 also formed from a microchannel plate.

Abstract: A mass spectrometer comprises an ion source (11), an ion injection arrangement (12), field generator defined by shaped electrodes (14, 16) and a detector (18) to detect ions. The electrodes (14, 16) are shaped so as to provide therebetween a field of substantially hyper-logarithmic form whereby ions can be trapped within a potential well of the field for analysis.