Patent classifications
H01J49/403
MALDI-TOF mass spectrometers with delay time variations and related methods
MALDI-TOF MS systems have solid state lasers and successive and varied delay times between ionization and acceleration (e.g. extraction) to change focus masses during a single sample signal acquisition without requiring tuning of the MS by a user. The (successive) different delay times can change by 1 ns to about 500 ns, and can be in a range that is between 1-2500 nanoseconds.
Wide-range high mass resolution in reflector time-of-flight mass spectrometers
The invention relates to the operation of an energy-focusing and solid-angle-focusing reflector for time-of-flight mass spectrometers with pulsed ion acceleration into a flight tube, e.g. from an ion source with ionization by matrix-assisted laser desorption (MALDI). The objective of the invention is to generate high mass resolution in wide mass ranges up to high masses above eight kilodaltons by varying at least one operating voltage on one of the diaphragms of the reflector which can be varied according to a suitable time function during the spectrum acquisition. It may also be advantageous to adapt the operation of the accelerating voltages in the starting region of the ions accordingly. These measures make it possible to achieve a mass resolution much higher than R=100,000 in a wide mass range extending up to and above eight kilodaltons.
Ion trap
An ion trap having a segmented electrode structure having a plurality of segments consecutively positioned along an axis, wherein each segment of the segmented electrode structure includes a plurality of electrodes arranged around the axis. A first voltage supply is configured to operate in a radially confining mode in which at least some electrodes belonging to each segment are supplied with at least one AC voltage waveform so as to provide a confining electric field for radially confining ions within the segment. A second voltage supply is configured to operate in a trapping mode in which at least some of the electrodes belonging to the segments are supplied with different DC voltages so as to provide a trapping electric field that has an axially varying profile for urging ions towards and trapping ions in a target segment of the plurality of segments. A first chamber is configured to receive ions from an ion source, wherein a first subset of the segments are located within the first chamber. A second chamber is configured to receive ions from the first chamber, wherein a second subset of the segments are located within the second chamber, and wherein the target segment is one of the second subset of segments. A gas pump is configured to pump gas out from the second chamber so as to provide the second chamber with a lower gas pressure than the first chamber. A gas flow restricting section is located between the first chamber and second chamber, wherein the gas flow restricting section is configured to allow ions to pass from the first chamber to the second chamber whilst restricting gas flow from the first chamber to the second chamber.
Time-of-flight mass spectrometer
An acceleration voltage generator generates a high-voltage pulse applied to a push-out electrode, by operating a switch section to turn on and off a high direct-current voltage generated by a high-voltage power supply. A drive pulse signal is supplied from a controller to the switch section through a primary-side drive section, transformer, and secondary-side drive section. A primary-voltage controller receives a measurement result of ambient temperature of the acceleration voltage generator from a temperature sensor, and controls a primary-side power supply to change a primary-side voltage according to the temperature, thereby adjusting the voltage applied between the two ends of a primary winding of the transformer. The adjustment made on the primary-side voltage changes a slope angle of rise of a gate voltage in the MOSFET, and enables a correction to a discrepancy in the timing of the rise/fall of the high-voltage pulse caused by change in ambient temperature.
MULTI-REFLECTING TIME-OF-FLIGHT MASS SPECTROMETERS
A multi-reflecting time of flight mass analyser is disclosed in which the ion flight path is maintained relatively small and the duty cycle is made relatively high. Spatial focussing of the ions in the dimension (z-dimension) in which the mirrors (36) are elongated can be eliminated whilst maintaining a reasonably high sensitivity and resolution.
Orthogonal acceleration time-of-flight mass spectrometry
A multipole ion guide (30) including a plurality of rod electrodes arranged at an angle to the central axis (C) is placed within a collision cell (13) located in the previous stage of an orthogonal accelerator (16). Radio-frequency voltages with opposite phases are applied to the rod electrodes of the ion guide (30) so that any two rod electrodes neighboring each other in the circumferential direction have opposite phases of the voltage. A depth gradient of the pseudopotential is thereby formed from the entrance end toward the exit end within the space surrounded by the rod electrodes, and ions are accelerated by this gradient. During an ion-accumulating process, a direct voltage having the same polarity as the ions is applied to the exit lens electrode (132) to form a potential barrier for accumulating ions. Among the ions repelled by the potential barrier, ions having smaller m/z return closer to the entrance end. Therefore, when the potential barrier is removed and ions are discharged, ions having smaller m/z are discharged at later points in time than those having larger m/z. Therefore, a wide m/z range of ions can be simultaneously accelerated and ejected by an orthogonal accelerator (16).
Space focus time of flight mass spectrometer
A Time of Flight mass spectrometer is disclosed wherein a fifth order spatial focusing device is provided. The device which may comprise an additional stage in the source region of the Time of Flight mass analyser is arranged to introduce a non-zero fifth order spatial focusing term so that the combined effect of first, third and fifth order spatial focusing terms results in a reduction in the spread of ion arrival times T of ions arriving at the ion detector.
High-throughput cryogenic spectroscopy for glycan analysis
A method for analyzing a plurality of molecules with cryogenic vibrational spectroscopy including the steps of providing a packet of molecules in a ionized form, injecting the packet into an ion mobility section, spatially separating the ions of the packet into subpackets according to their collisional cross section (CCS), recompressing the subpackets, by removing an empty space between them, loading the ions into a cryogenic ion trap by keeping subpackets with different collisional cross section in a respective separate compartment, cooling the ions in collisions with a buffer gas, tagging the ions by attaching a messenger molecule, sending a pulse to the trap to excite vibrations of the cold, trapped, and messenger-tagged ions, and separately ejecting ion subpacket from the trap into an extraction region of a time-of-flight mass spectrometer and measuring the number of remaining messenger-tagged ions and untagged ions for each subpacket.
Mass analyzer with 3D electrostatic field
A mass analyser for use in a mass spectrometer, the mass analyser having: a set of sector electrodes spatially arranged to provide an electrostatic field in a 2D reference plane suitable for guiding ions along an orbit in the 2D reference plane, wherein the set of sector electrodes extend along a drift path that is locally orthogonal to the reference plane so that, in use, the set of sector electrodes provide a 3D electrostatic field region; and an injection interface configured to inject ions into the mass analyser via an injection opening such that the ions injected into the mass analyser are guided by the 3D electrostatic field region along a 3D reference trajectory according to which ions perform multiple turns within the mass analyser whilst drifting along the drift path, wherein each turn corresponds to a completed orbit in the 2D reference plane. The injection interface includes at least one injection deflector located within the mass analyser, the at least one injection deflector being configured to deflect ions injected into the mass analyser in the direction of the drift path, wherein the injection interface is preferably configured so that ions guided along the 3D reference trajectory are, after injection into the mass analyser, kept adequately distant from the injection opening such that they are substantially unaffected by electric field distortions around the injection opening.
MASS AND/OR ION MOBILITY SPECTROMETRY
A method of analysing ions comprises separating ions according to a first physico-chemical property by passing the ions through an ion separation device, and measuring the transit time of an ion through the ion separation device. The method further comprises detecting the ion using a charge-resolving ion detector so as to determine the charge of the ion, and using the transit time and the charge of the ion to determine a second physico-chemical property of the ion.