The University of British Columbia

Mds Inc.

Mds Analytical Technologies, a Business Unit of Mds Inc.

Dh Technologies Development Pte. Ltd.

Donald J Douglas

Bruce Andrew Collings

Chuan-Fan Ding

Bradley B Schneider

Frank Londry

Nikolai Konenkov

David D Y Chen

Jennifer M Campbell

Mikhail Sudakov

Xianzhen Zhao

Mikhail Soudakov

Zhaohui Du

Chuanfan Ding

Lars Konermann

David D Chen

A method of processing ions in a quadrupole rod set is provided, comprising a) establishing and maintaining a two-dimensional substantially quadrupole field having a quadrupole harmonic with amplitude Aand a selected higher order harmonic with amplitude Aradially confining ions having Mathieu parameters a and q within a stability region defined in terms of the Mathieu parameters a and q; c) adding an auxiliary excitation field to transform the stability region into a plurality of smaller stability islands defined in terms of the Mathieu parameters a and q; and, d) adjusting the two-dimensional substantially quadrupole field to place ions within a selected range of mass-to-charge ratios within a selected stability island in the plurality of stability islands.

Method of operating quadrupoles with added multipole fields to provide mass analysis in islands of stability

A mass spectrometer and a method of operating and building same is provided in which a hexapole component is deliberately added to a substantially quadrupole field. This can result in unwanted octopole and dipole fields also being added to the substantially quadrupole field. Modifications to the mass spectrometer as well as ways of operating the mass spectrometer are provided for dealing with the unwanted octopole and dipole fields.

Linear quadrupoles with added hexapole fields and method of building and operating same

An apparatus with means for controlling ion generation is discussed. The apparatus comprises a plurality of ion sources, at least one counter electrode mounted downstream for the ion sources and at least one ion controlling element mounted relative to at least one of the ion sources. Each ion controlling element is alternated between a first condition where the operation of at least one of the ion sources is enabled and a second condition where the operation of at least one of the ion sources is disabled. This concept may also be extended to an ion source apparatus having a single ion source with an ion lens mounted relative thereto. The present invention also provides a method for controlling the operation of the aforementioned apparatus. The invention further provides an apparatus and a method for the generation of ion pulses.

High throughput ion source with multiple ion sprayers and ion lenses

A method and apparatus for manipulating ions using a two-dimensional substantially quadrupole field, and a method of manufacturing and operating an apparatus for manipulating ions using a two-dimensional substantially quadrupole field are described. The field has a quadrupole harmonic with amplitude Aand a hexapole harmonic with amplitude A. The amplitude Aof the hexapole component of the field is selected to improve the performance of the field with respect to ion selection and ion fragmentation.

Method and apparatus for providing two-dimensional substantially quadrupole fields having selected hexapole components

An ion lens is used to focus ions produced by various types of ion sources which are substantially at atmospheric pressure. The ions are focused to the inlet of a downstream mass spectrometer or other devices which require a larger and more stable ion flux improved performance. The ion lens is mounted in close proximity to the sprayer tip. The ion lens increases the total ion count rate summed over all of the generated ions. The ion lens may also be employed to vary the degree of ion fragmentation and the charge state pattern of the generated ions. The ion lens may also result in a more stable ion signal. Furthermore, more than one ion lens may be used. This invention may also be extended to multisprayer ion sources.

Atmospheric pressure ion lens for generating a larger and more stable ion flux

A mass spectrometer having an elongated rod set, and a method of operating same. The rod set has an entrance end, an exit end and a longitudinal axis. Ions are admitted into the entrance end of the rod set. At least some of the ions are trapped in the rod set by producing a barrier field at an exit member adjacent to the exit end of the rod set and by producing an RF field between the rods of the rod set adjacent at least the exit end of the rod set. The RF and barrier fields interact in an extraction region adjacent to the exit end of the rod set to produce a fringing field. Ions in the extraction region are energized to mass selectively eject at least some ions of a selected mass to charge ratio axially from the rod set past the barrier field. The RF field is a two-dimensional substantially quadrupole field having a quadrupole harmonic with amplitude A, an octopole harmonic with amplitude A, and a hexadecapole harmonic with amplitude A. Ais less than A, and Ais greater than 0.1% of A.

Axial ejection with improved geometry for generating a two-dimensional substantially quadrupole field

A method and apparatus for manipulating ions using a two-dimensional substantially quadrupole field, and a method of manufacturing an apparatus for manipulating ions using a two-dimensional substantially quadrupole field are described. The field has a quadrupole harmonic with amplitude A, an octopole harmonic with amplitude A, and higher order harmonics with amplitudes Aand A. The amplitude Ais less than A. The Acomponent of the field is selected to improve the performance of the field with respect to ion selection and ion fragmentation. The selected Acomponent can be added by selecting a degree of asymmetry under a 90&#xb0; rotation about a central axis of the quadrupole. The degree of asymmetry is selected to be sufficient to provide the selected Acomponent.

Geometry for generating a two-dimensional substantially quadrupole field

A method of and apparatus for analyzing a stream of ions first subjects astream of ions to a first mass analysis step, to select ions having a mass-to-charge ratio in a first desired range; this enables a mass analyzer with highresolution to be used. The selected ions are then passed into a radiofrequency linear ion trap containing a gas. The trapped ions are caused to collide with the gas, either by being injected with a high axial energy or by application of external excitation to cause fragmentation. Fragment ions of a given mass-to-charge ratio can then be isolated and excited to produce fragments of fragments. This process can be repeated to give multiple steps of mass spectrometry, MS . The fragment ions, and undissociated precursorions are then passed out of the linear ion trap and subjected to a further mass analysis step, for example in a time of flight device, to determine the mass spectrum of the ions.

Method and apparatus for multiple stages of mass spectrometry

A method is provided of operating a mass spectrometer apparatus comprising a pair of quadrupole rod sets. Each quadrupole rod set is operated in a mass resolving mode. They may be operated in the same or different stability regions. The rod sets are operated to select essentially ions of the same mass to charge ratio, and are operated such that the combined resolution of the two rod sets is greater than the resolution of either rod set. The rod sets can be operated at relatively low resolution, with the combined peak shape from the two rod sets showing high resolution. This can make up for mechanical imperfections in the rod sets, losses due to high gas pressures, etc. A mass shift can be provided to give the desired resolution. The rod sets can be close coupled, and for this purpose neutralizing capacitors can be provided to prevent electrical interference between adjacent rod sets. The rod sets can be provided with the same frequency signal, which preferably is a phase locked and shifted, to give enhanced sensitivity.

Mass spectrometer including multiple mass analysis stages and method of operation, to give improved resolution

A method and apparatus are provided for determining rates and mechanisms of reactions in solution. The method comprises mixing reactants together and then passing the reactants, after mixing, to an electrospray or other ion source. The apparatus is configured so that the reaction time can be determined. This can either be by way of a capillary of known length and volume extending from a reaction tee or other mixing device, so that the reaction time can be determined from the capillary volume and flow rate, and/or by way of a container of fixed volume from which the reactants pass. From the ion source, ions pass into a mass spectrometer, where a mass spectrum is measured. By varying the reaction time, and measuring the different mass spectra, the rate of reaction can be determined.

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Vancouver, Canada

Donald J Douglas