Abstract: A device and associated method are disclosed for interfacing an ion trap to a pulsed mass analyzer (such as a time-of-flight analyzer) in a mass spectrometer. The device includes a plurality of separate confinement cells and structures for directing ions into a selected one of the confinement cells. Ions are ejected from the ion trap in a series of temporally successive ion packets. Each ion packet (which may consist of ions of like mass-to-charge ratio), is received by the ion interface device, fragmented to form product ions, and then stored and cooled in the selected confinement cell. Storage and cooling of the ion packet occurs concurrently with the receipt and storage of at least one later-ejected ion packet. After a predetermined cooling period, the ion packet is released to the mass analyzer for acquisition of a mass spectrum.

Abstract: An electrospray ion source apparatus comprises: a plurality of emitter capillaries, each comprising an internal bore for transporting a portion of a liquid sample from a source, an electrode portion for providing a first applied electric potential and an emitter tip for emitting a cloud of charged particles generated from the liquid sample portion; a counter electrode for providing a second applied electric potential different from the first applied electric potential; and at least one shield electrode disposed at least partially between the counter electrode and the emitter tip of at least one of the emitter capillaries for providing a third applied electric potential intermediate to the first and second applied electric potentials, wherein the at least one shield electrode is configured such that provision of the third applied electric potential to the at least one shield electrode minimizes electric field interference effects between the plurality of emitter capillaries.

Abstract: A novel high ion storage/ ion mobility separation mass spectrometer that provides for a high duty cycle of operation is presented herein. In particular, the example embodiments, as disclosed herein, provides for a high ion storage/ion mobility instrument that beneficially includes a two-dimensional (2D) plurality of adjacently arranged ion confinement channels to provide a high storage bank of a desired mass range of ions. Such ions, via ion mobility transport, are separated into smaller fractions of an overall mass window into desired confinement regions of the disclosed 2D confinement channels and thereafter transferred out in a manner so as to enable the aforementioned novel high-duty cycle of sequential operation.

Abstract: An electrospray ion source apparatus comprises: a plurality of emitter capillaries, each comprising an internal bore for transporting a portion of a liquid sample from a source, an electrode portion for providing a first applied electric potential and an emitter tip for emitting charged particles generated from the liquid sample portion; a counter electrode for providing a second applied electric potential different from the first applied electric potential; and at least one shield electrode disposed at least partially between the counter electrode and the emitter tip of at least one of the emitter capillaries for providing a third applied electric potential intermediate to the first and second applied electric potentials, wherein the at least one shield electrode is configured such that provision of the third applied electric potential to the at least one shield electrode provides a uniformity of emission of charged particles from the plurality of emitter tips.

Abstract: A device and associated methods of operations are disclosed for interfacing on ion trap to a mass analyzer, such as a TOF mass analyzer. The device includes a plurality of sequentially arranged confinement cells having fixed locations. A group of ions, e.g., ions within a relatively narrow window of mass-to-charge ratio, is received by the device from the ion trap, undergoes fragmentation, and is transported through the device from a first to final confinement cell by a series of transfers between adjacent cells. The ion group is confined in each cell for a prescribed cooling period. By providing a suitable aggregate ion confinement time and by enabling concurrent transport and cooling of successively ejected ion groups, the ions are cooled sufficiently to enable the acquisition of mass spectra at high resolution, without having to substantially delay the ejection of a subsequent group of ions from the ion trap until cooling of the previous group is completed.

Abstract: A novel electron multiplier that regulates in real time the gain of downstream dynodes as the instrument receives input signals is introduced. In particular, the methods, electron multiplier structures, and coupled control circuits of the present invention enable a resultant on the fly control signal to be generated upon receiving a predetermined threshold detection signal so as to enable the voltage regulation of one or more downstream dynodes near the output of the device. Accordingly, such a novel design, as presented herein, prevents the dynodes near the output of the instrument from being exposed to deleterious current pulses that can accelerate the aging process of the dynode structures that are essential to the device.

Abstract: An electrospray ion source apparatus comprises: a plurality of emitter capillaries, each comprising an internal bore for transporting a portion of a liquid sample from a source, an electrode portion for providing a first applied electric potential and an emitter tip for emitting charged particles generated from the liquid sample portion; a counter electrode for providing a second applied electric potential different from the first applied electric potential; and at least one shield electrode disposed at least partially between the counter electrode and the emitter tip of at least one of the emitter capillaries for providing a third applied electric potential intermediate to the first and second applied electric potentials, wherein the at least one shield electrode is configured such that provision of the third applied electric potential to the at least one shield electrode provides a uniformity of emission of charged particles from the plurality of emitter tips.

Abstract: An automatic gain control (AGC) technique and apparatus is introduced herein for any temporally non-uniform ion beam, such as, for example, an ion beam produced by a MALDI ion source so as to minimize space charge effects. The disclosed configurations and techniques can be achieved by using an ion optical gating element and applying a desired signal waveform (e.g., a square wave) having a predetermined duty cycle. The applied voltage amplitude of such a signal can be configured to switch between a voltage which fully transmits the ions, and a voltage which does not transmit any ions. The frequency is chosen to result in a period which is significantly lower than the smallest non-uniformity period. Techniques of the present invention can also be extended to methods of AGC which can use a single ion injection event from the ion source to avoid variations in ion numbers from an unstable ion source.

Abstract: A method and apparatus of combining two independent multipoles in an interlaced fashion to form a resultant multipole structure is introduced. Such an arrangement enables ions from two separate sources to be merged along a predetermined longitudinal direction but also enables in the reverse path, predetermined portions of ions from a single source to be directed along one or more ion channel paths to also enable, for example, simultaneous collection by a Time of Flight (TOF) mass analyzer and an ion trap.

Abstract: A mass spectrometer includes at least one ion selector, at least one collision cell, and an ion path switching device arranged to define a looped ion path around which ions derived from a sample may be sent multiple times (without reversal of ion travel) in order to effect a desired number of isolation/fragmentation cycles for MSn analysis. When the desired number of isolation/fragmentation cycles have been completed, the ion path switching device directs the ions to a detector or a separate mass analyzer for acquisition of a mass spectrum.

Abstract: A high field asymmetric waveform ion mobility spectrometer (FAIMS) includes at least two focusing electrodes that are separated one from the other by a gap, which decreases in width along a direction of ion flow. Within the gap is disposed an electrode assembly including a first electrode and a second electrode, approximately flat surfaces of the first and second electrodes facing one another so as to define a space of approximately uniform thicknesses therebetween. During use electrical signals are applied via an electrical contact on at least one of the first electrode and the second electrode, and on each one of the at least two focusing electrodes. The electrical signals are for establishing electrode electric field conditions within the space between the first electrode and the second, for selectively transmitting ions therethrough and for directing the selectively transmitted ions in a direction away from one of the at least two focusing electrodes and toward a central portion of the space.

Abstract: Systems and methods of the invention include a branched radio frequency multipole configured to act, for example, as an ion guide. The branched radio frequency multipole comprises multiple ion channels through which ions can be alternatively directed. The branched radio frequency multipole is configured to control which of the multiple ion channels ions are directed, through the application of appropriate potentials.

Abstract: A device for transporting and focusing ions in a low vacuum or atmospheric-pressure region of a mass spectrometer is constructed from a plurality of longitudinally spaced apart electrodes to which oscillatory (e.g., radio-frequency) voltages are applied. In order to create a tapered field that focuses ions to a narrow beam near the device exit, the inter-electrode spacing or the oscillatory voltage amplitude is increased in the direction of ion travel.

Abstract: A method and apparatus of combining two independent multipoles in an interlaced fashion to form a resultant multipole structure is introduced. Such an arrangement enables ions from two separate sources to be merged along a predetermined longitudinal direction but also enables in the reverse path, predetermined portions of ions from a single source to be directed along one or more ion channel paths to also enable, for example, simultaneous collection by a Time of Flight (TOF) mass analyzer and an ion trap.

Abstract: A high field asymmetric waveform ion mobility spectrometer (FAIMS) includes at least two focusing electrodes that are separated one from the other by a gap, which decreases in width along a direction of ion flow. Within the gap is disposed an electrode assembly including a first electrode and a second electrode, approximately flat surfaces of the first and second electrodes facing one another so as to define a space of approximately uniform thicknesses therebetween. During use electrical signals are applied via an electrical contact on at least one of the first electrode and the second electrode, and on each one of the at least two focusing electrodes. The electrical signals are for establishing electrode electric field conditions within the space between the first electrode and the second, for selectively transmitting ions therethrough and for directing the selectively transmitted ions in a direction away from one of the at least two focusing electrodes and toward a central portion of the space.

Abstract: An automatic gain control (AGC) technique and apparatus is introduced herein for any temporally non-uniform ion beam, such as, for example, an ion beam produced by a MALDI ion source so as to minimize space charge effects. The disclosed configurations and techniques can be achieved by using an ion optical gating element and applying a desired signal waveform (e.g., a square wave) having a predetermined duty cycle. The applied voltage amplitude of such a signal can be configured to switch between a voltage which fully transmits the ions, and a voltage which does not transmit any ions. The frequency is chosen to result in a period which is significantly lower than the smallest non-uniformity period. Techniques of the present invention can also be extended to methods of AGC which can use a single ion injection event from the ion source to avoid variations in ion numbers from an unstable ion source.

Abstract: A mass spectrometer includes a multipole having a main RF field for radially containing ions generally on a central axis. The multipole has first and second axial DC fields in opposite first and second direction along a length of the multipole. The first and second axial DC fields approach or add substantially to zero on the central axis. The multipole has an excitation voltage applied thereto for selectively exciting the ions of desired m/z ratios off the central axis. The excitation voltage thus causes excursion of the ions into a region where either the first or second axial DC field is strong. Thus, excitation of the ions and the DC fields cause ion drift toward a front end or a back end of the multipole. Further excitation moves the ions into regions of the DC fields that overcome barriers and causes axial ejection of the ions from the multipole.

Abstract: A mass spectrometer includes at least one ion selector, at least one collision cell, and an ion path switching device arranged to define a looped ion path around which ions derived from a sample may be sent multiple times (without reversal of ion travel) in order to effect a desired number of isolation/fragmentation cycles for MSn analysis. When the desired number of isolation/fragmentation cycles have been completed, the ion path switching device directs the ions to a detector or a separate mass analyzer for acquisition of a mass spectrum.

Abstract: An ion source is disclosed for forming multiply-charged analyte ions from a solid sample. A beam of pulsed radiation is directed onto a portion of the sample to desorb analyte molecules. A retaining structure holding a solvent volume is positioned proximate the sample. Desorbed analyte molecules contact a free surface of the solvent and pass into solution. The solution is then conveyed through an outlet passageway to an electrospray apparatus, which introduces a spray of charged solvent droplets into an ionization chamber.

Abstract: A device for transporting and focusing ions in a low vacuum or atmospheric-pressure region of a mass spectrometer is constructed from a plurality of longitudinally spaced apart electrodes to which oscillatory (e.g., radio-frequency) voltages are applied. In order to create a tapered field that focuses ions to a narrow beam near the device exit, the inter-electrode spacing or the oscillatory voltage amplitude is increased in the direction of ion travel.