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: An electrospray ion source for a mass spectrometer for generating ions of an analyte from a sample comprising the analyte dissolved in a liquid solvent comprises: an electrode receiving the sample and comprising at least a first plurality of protrusions protruding from a base, each protrusion of the at least a first plurality of protrusions having a respective tip; and a voltage source, wherein, in operation of the electrospray ion source, the sample is caused to move, in the presence of a gas or air, from the base to each protrusion tip along a respective protrusion exterior so as to form a respective stream of charged particles emitted towards an ion inlet aperture of the mass spectrometer under application of voltage applied to the electrode from the voltage source.

Abstract: An electrospray ion source comprises a source of analyte-bearing liquid; a source of sheath gas; a plurality of liquid conduits, each configured so as to receive a portion of the analyte-bearing liquid; at least one electrode associated with the plurality of liquid conduits for producing electrospray emission of charged droplets from an outlet of each of the liquid conduits; a power supply electrically coupled to the at least one electrode for maintaining the at least one electrodes at an electrical potential; and either one or a plurality of sheath gas conduits, each sheath gas conduit comprising an inlet configured to receive sheath gas and an outlet configured to emit a sheath gas flow that circumferentially surrounds, in at least two dimensions, a portion of the emitted charged droplets.

Abstract: A method for analyzing a sample comprising the steps of: generating ions from the sample within an ionization chamber at substantially atmospheric pressure; entraining the ions in a background gas; transferring the background gas and entrained ions to an evacuated chamber of a mass spectrometer system using a single-piece capillary having an inlet end and an outlet end, wherein a portion of the capillary adjacent to the outlet end comprises an inner diameter that is greater than an inner diameter of an adjoining portion of the capillary; and analyzing the ions using a mass analyzer of the mass spectrometer system.

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 electrospray ion source for a mass spectrometer includes an electrode comprising at least a first plurality of protrusions protruding from a base, each protrusion of the at least a first plurality of protrusions having a respective tip; a conduit for delivering an analyte-bearing liquid to the electrode; and a voltage source, wherein, in operation of the electrospray ion source, the analyte-bearing liquid is caused to move, in the presence of a gas or air, from the base to each protrusion tip along a respective protrusion exterior so as to form a respective stream of charged particles emitted towards an ion inlet aperture of the mass spectrometer under application of voltage applied to the electrode from the voltage source.

Abstract: An ion transfer tube for a mass spectrometer comprises a core member and a first jacket tube member at least partially enclosing the core member and providing one or more channels therethrough. A method of forming an ion transfer tube, comprises: providing a first jacket tube member having a length and an internal bore, the internal bore passing along the length and defining an interior surface of circular cross section; removing at least one portion of the first jacket tube member adjacent to the interior surface so as to form at least one groove, channel, slot, recess or embayment of or in the interior surface; and providing a core member within the bore of the jacket tube member such that remnant portions of the interior surface of circular cross section mate against portions of an exterior surface of the core member.

Abstract: An ion transfer tube for a mass spectrometer comprises a tube member having an inlet end and an outlet end; and at least one bore extending through the tube member from the inlet end to the outlet end, the at least one bore having a non-circular cross section. A method of forming an ion transfer tube comprises the steps of providing a tube member having a length and an internal bore, the internal bore having a wall of circular cross section; and etching or eroding portions of the tube member adjacent to the wall so as to form an enlarged bore having a non-circular cross section.

Abstract: A system for preventing backflow as part of an ion source arrangement is introduced. Such a system incorporates a novel continuous flow guide within a source, such as an API ion source. In the spray direction, the cross-sectional area that defines the first portion of the internal volume initially decreases in a convergent-like manner and thereafter increases in a divergent-like manner towards the exit opening of the source housing. Such a flow guide has been designed as an integral part of an ion source housing to provide for an optimal unidirectional flow past a sampling orifice of a mass spectrometer inlet. Accordingly, the novel design of the present invention prevents recirculation and thus minimizes carryover, chemical noise, and source turbulence and as an added benefit, enables a user to easily clean such a system during maintenance.

Abstract: An ion transfer tube having an ion inlet and an ion outlet comprises: a first tube member comprising an electrically resistive material and having a first end comprising the ion inlet and a second end; a first electrode electrically coupled to the first tube member; a second tube member having a first end in leak-tight contact with the second end of the first tube member and a second end comprising the ion outlet; a second electrode electrically coupled to either the first tube member or the second tube member; and a heater thermally coupled to at least one of the tube members, wherein, in operation, an electrical potential difference applied between the electrodes produces an electric field within the first tube member that urges charged particles through the first tube member into the second tube member and the heater supplies heat to the charged particles within the ion transfer tube.

Abstract: An electrospray ion source for a mass spectrometer includes an electrode comprising at least a first plurality of protrusions protruding from a base, each protrusion of the at least a first plurality of protrusions having a respective tip; a conduit for delivering an analyte-bearing liquid to the electrode; and a voltage source, wherein, in operation of the electrospray ion source, the analyte-bearing liquid is caused to move, in the presence of a gas or air, from the base to each protrusion tip along a respective protrusion exterior so as to form a respective stream of charged particles emitted towards an ion inlet aperture of the mass spectrometer under application of voltage applied to the electrode from the voltage source.

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 electrospray ion source comprises a source of analyte-bearing liquid; a source of sheath gas; a plurality of liquid conduits, each configured so as to receive a portion of the analyte-bearing liquid; at least one electrode associated with the plurality of liquid conduits for producing electrospray emission of charged droplets from an outlet of each of the liquid conduits; a power supply electrically coupled to the at least one electrode for maintaining the at least one electrodes at an electrical potential; and either one or a plurality of sheath gas conduits, each sheath gas conduit comprising an inlet configured to receive sheath gas and an outlet configured to emit a sheath gas flow that circumferentially surrounds, in at least two dimensions, a portion of the emitted charged droplets.

Abstract: A device for improved transportation and focusing of ions in a low vacuum or atmospheric-pressure region of a mass spectrometer is constructed from one or more electro-dynamic or electrostatic focusing lenses that is/are coupled to the first electrode of a stacked ring ion guide (SRIG) to which oscillatory (e.g., radio-frequency) voltages are applied. Such configurations as disclosed herein, minimizes deleterious field effects and/or repositioning problems of desired ion transfer instruments that utilize such stacked ring ion guides by generally configuring the outlet end of the ion transfer device to a desired position within the electro-dynamic or electro-static focusing lens(es).

Abstract: A system for preventing backflow as part of an ion source arrangement is introduced. Such a system incorporates a novel continuous flow guide within a source, such as an API ion source. In the spray direction, the cross-sectional area that defines the first portion of the internal volume initially decreases in a convergent-like manner and thereafter increases in a divergent-like manner towards the exit opening of the source housing. Such a flow guide has been designed as an integral part of an ion source housing to provide for an optimal unidirectional flow past a sampling orifice of a mass spectrometer inlet. Accordingly, the novel design of the present invention prevents recirculation and thus minimizes carryover, chemical noise, and source turbulence and as an added benefit, enables a user to easily clean such a system during maintenance.

Abstract: Methods for operating a mass spectrometer having at least one component having mass-dependent transmission, comprising: injecting a first sample of ions having a first mass range into an ion accumulator for a first injection time under first operating conditions suitable for optimizing transmission of ions of the first range; acquiring a full-scan mass spectrum of the first sample of ions; selecting ion species having a second mass range different than the first range; calculating a second injection time, the second injection time suitable for injecting a population of the selected ion species into the ion accumulator under second operating conditions suitable for optimizing transmission of ions of the second range; injecting a second sample of ions having the selected ion species into the ion accumulator for the second injection time under the second operating conditions; and acquiring a mass spectrum of ions derived from the selected ion species.

Abstract: A method for analyzing a sample comprising the steps of: generating ions from the sample within an ionization chamber at substantially atmospheric pressure; entraining the ions in a background gas; transferring the background gas and entrained ions to an evacuated chamber of a mass spectrometer system using an ion transfer tube having an inlet end and an outlet end, wherein a portion of the ion transfer tube adjacent to the outlet end comprises an inner diameter that is greater than an inner diameter of an adjoining portion of the ion transfer tube; and analyzing the ions using a mass analyzer of the mass spectrometer system.

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 for directing ions from an ionization source to a mass analyzer is provided. The method includes producing ions from a sample in an ionization source. Some of the ions are transferred to a first region via a passageway that is in fluid communication with the ionization source. Next, some of the ions are sampled from the first region into a second region via an aperture that is defined thorough a partition element. The aperture is centered about a longitudinal axis that passes through an ion transfer element within the second region. An electric field is established for deflecting some of the ions that pass through the aperture of the partition element. In particular, the electric field is directed transverse to the longitudinal axis such that relatively more ions enter an input end of the ion transfer element compared to when the ions are not deflected.

Abstract: A device for improved transportation and focusing of ions in a low vacuum or atmospheric-pressure region of a mass spectrometer is constructed from one or more electro-dynamic or electrostatic focusing lenses that is/are coupled to the first electrode of a stacked ring ion guide (SRIG) to which oscillatory (e.g., radio-frequency) voltages are applied. Such configurations as disclosed herein, minimizes deleterious field effects and/or repositioning problems of desired ion transfer instruments that utilize such stacked ring ion guides by generally configuring the outlet end of the ion transfer device to a desired position within the electro-dynamic or electro-static focusing lens(es).