摘要:
In a mass spectrometer, ions from an ion source pass through an inlet aperture into a vacuum chamber for transmitting prior to mass analysis by the mass analyzer. The configuration of the inlet aperture forms a sonic orifice or sonic nozzle and with a predetermined vacuum chamber pressure, a supersonic free jet expansion is created in the vacuum chamber that entrains the ions within the barrel shock and Mach disc. Once formed, at least one ion guide with a predetermined cross-section to essentially radially confine the supersonic free jet expansion can focus the ions for transmission through the vacuum chamber. This effectively improves the ion transmission between the ion source and the mass analyzer.
摘要:
In a mass spectrometer, ions from an ion source pass through an inlet aperture into a vacuum chamber for transmitting prior to mass analysis by the mass analyzer. The configuration of the inlet aperture forms a sonic orifice or sonic nozzle and with a predetermined vacuum chamber pressure, a supersonic free jet expansion is created in the vacuum chamber that entrains the ions within the barrel shock and Mach disc. Once formed, an ion guide with a predetermined cross-section to essentially radially confine the supersonic free jet expansion can focus the ions for transmission through the vacuum chamber. This effectively improves the ion transmission between the ion source and the mass analyzer.
摘要:
A multi-device interface for use in mass spectrometry for interfacing one or more ion sources to one or more downstream devices. The multi-device interface comprises three or more multipole rod sets configured as either an input rod set or an output rod set depending on potentials applied to the multipole rod sets. The multipole rod sets configured as an input rod set are connectable to the one or more ion sources for receiving generated ions therefrom and sending the ions to at least one multipole rod set configured as an output multipole rod set. The output multipole rod sets are connectable to a downstream device for sending the generated ions thereto. At least two of the multipole rod sets are configured as input rod sets or at least two of the multipole rod sets are configured as output rod sets.
摘要:
A mass analyzer for use in a mass spectrometry system comprises an elongate rod set. The rod set has first and second ends and an inscribed circle within the rod set. The radius of the rod set varies from one end of the rod set to the other, so that ions of different mass to charge ratios will become unstable at different locations along the rod set. This characteristic can then be used to cause ejection of ions at different locations along the rod set, in a mass dependent manner. Detectors placed linearly along the rod set can then be used to detect ions and determine the mass of the ions from their ejection locations.
摘要:
A method and mass spectrometer for filtering ions are provided. The mass spectrometer generally comprises an ion guide, a quadrupole mass filter, a collision cell and a time of flight (ToF) detector, and is enabled to transmit an ion beam through to the ToF detector. The mass spectrometer is operated in MS mode, such that ions in the ion beam remain substantially unfragmented, the quadrupole mass filter operating at a pressure substantially lower than in either of the ion guide and the collision cell. The quadrupole mass filter is operated in a bandpass mode such that ions outside of a range of interest are filtered from the ion beam, leaving ions inside the range of interest in the ion beam. The ions inside the range of interest are analyzed at the ToF detector.
摘要:
Dual TDC-ADC detection systems for time of flight mass spectrometry are disclosed herein. Detection systems based upon TDC generally provide higher timing resolution as opposed to detection systems based upon ADC. However, ADC generally provides increased dynamic range over TDC. By combining TDC and ADC into a tandem detector, and adjusting performance parameters of the respective converter types, the dynamic range of the dual TDC-ADC detection can be extended beyond what either detector type could have achieved individually. Composite time of flight mass spectra can be generated by aggregating individual mass spectra acquired from multiple time-of-flight extractions, and selecting the number of time-of-flight extractions to ensure overlap between the ADC and TDC dynamic ranges in the dual TDC-ADC detector system.
摘要:
There is provided a linear ion trap having an ion guide and a method of operating same. The ion guide has a first end and a second end. The method involves a) providing a first group of ions within the ion guide; b) providing a second group of ions within the ion guide, the second group of ions being opposite in polarity to the first group of ions; c) providing an RF drive voltage to the ion guide to radially confine the first group of ions and the second group of ions in the ion guide; d) providing a gas flow of an inert gas in a first axial direction away from the first end of the ion guide and toward a middle of the ion guide to repel both the first group of ions and the second group of ions from the first end of the ion guide; and, e) providing a trapping region barrier for repelling both the first group of ions and the second group of ions away from the second end of the ion guide. The gas flow in the first axial direction and the trapping region barrier together define a main trapping region for trapping both the first group of ions and the second group of ions.
摘要:
An apparatus and method for dispensing low volumes of an analyte solution. The apparatus comprises: (a) a receiver defining an ejection cavity and an outlet downstream of and in fluid communication with the ejection cavity; (b) first and second fluid conduits coupled to the receiver and defining respective first and second fluid flow paths in fluid communication with the ejection cavity; (c) an analyte generating apparatus operatively coupled to the first fluid conduit and operable to deliver analyte solution along the first fluid flow path to the ejection cavity; and (d) a dispensing mechanism operatively coupled to the second fluid conduit and operable to deliver a fluid buffer along the second fluid flow path into the ejection cavity to displace analyte solution present therein through the outlet. The method involves filling the ejection cavity with an analyte solution at a selected rate and injecting a fluid buffer into the injection cavity to displace the analyte solution through the outlet.
摘要:
An ion guide 24 for a mass spectrometer 30 including means for ejecting ions of different mass-to-charge ratios from the ion guide towards a detector or other object or device. The ejecting means causes the ions to be ejected in a desired sequence. The ions travel at different rates according to their mass-to-charge ratios, so that they arrive at a desired point in space in a desired sequence, for example in a detector 56 of a mass spectrometer at substantially the same time.
摘要:
An apparatus for secondary ion mass spectrometry is provided having a target surface for supporting a sample on the target surface and an ion source configured to direct a beam of primary ions toward the sample to sputter secondary ions and neutral particles from the sample, A first chamber having an inlet provides gas to maintain high pressure at the sample for cooling the secondary ions and neutral particles, the high pressure being in the range of about 10−3 to about 1000 Torr. A method of secondary ion mass spectrometry is provided having a target surface for supporting a sample, directing a beam of primary ions toward the sample to sputter secondary ions and neutral particles from the sample, and providing a high pressure at the sample for cooling the secondary ions and neutral particles, the high pressure being in the range of about 10−3 to about 1000 Torr.