Thermo Finnigan LLC

Bruker Daltonics, Inc.

Other

Maurizio Splendore

Eloy R Wouters

Jean Jacques Dunyach

Paul R Atherton

Michael W Senko

Felician Muntean

Jean-Jacques Dunyach

Stephen Zanon

Christopher Mullen

Roy P Moeller

Rohan A Thakur

Jae C Schwartz

Viatcheslav V Kovtoun

R Paul Atherton

Rohan Thakur

William Siebert

The invention provides a cathode system for an Electron Ionization (EI) source comprising a filament and current supply posts, the current supply posts dividing the filament into segments and each current supply post supplying or returning the current for at least two segments of the filament. Each filament segment is connected, for instance by spot welding, to the supply posts delivering the heating current. The filament segments may be arranged in a row, or substantially parallel to each other. Filament segments arranged in a row may form a closed loop, for instance, a ring. Other embodiments encompass the filament shape of a helical coil.

Filament for mass spectrometric electron impact ion source

An ion guide that transports ions from an ion source at generally a high-pressure level to a mass analyzer at generally a low-pressure level has a plurality of identical electrodes fabricated with protruding elements that forming an ion tunnel or an ion funnel, when the electrodes are assembled around a common longitudinal axis. The protruding elements allow the generation of the radio frequency field necessary to radially confine ions. Each electrode may be machined from a solid block of conductive material, such as metal. The disclosed arrangement greatly simplifies the manufacturing process, reducing cost, and improving robustness and reliability of the ion guide itself.

Ion guide and electrode for its assembly

An assembly for use in an electrospray ion source includes a capillary for guiding a flow of liquid generally containing analyte(s) of interest, which is to be electrosprayed into an ionization chamber, a first tube at least partially encasing the capillary such that a first conduit for guiding a first heatable gas is created proximate the capillary and a hollow member that has an internal evacuated space and is located at the outer circumference of the capillary such that heat transfer from the first heatable gas flowing proximate the capillary to the liquid in the capillary is impeded. The assembly provides a simple and lean/compact way of preventing excessive heat transfer to the liquid in the capillary of an electrospray ion source.

Assembly for an electrospray ion source

An apparatus and method for introducing ions into a vacuum chamber of a mass spectrometer includes producing ions in an ionization chamber of an ion source. The ions are sampled into an intermediate pressure chamber via a first ion transfer tube. In particular, the pressure within the intermediate pressure chamber is maintained at a value that exceeds a maximum pressure for being sampled into the vacuum chamber of the mass spectrometer. Some of the ions are sampled from the intermediate pressure chamber via at least a second ion transfer tube, the at least a second ion transfer tube having an outlet end that is in communication with a low-pressure chamber. In particular, the pressure within the low-pressure chamber is maintained at a value that is less than a maximum pressure for being sampled into the vacuum chamber of the mass spectrometer. Some of the ions are sampled from the low-pressure chamber into the vacuum chamber of the mass spectrometer.

Apparatus and method for a multi-stage ion transfer tube assembly for use with mass spectrometry

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.

Ion population control in a mass spectrometer having mass-selective transfer optics

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.

Apparatus and methods for pneumatically-assisted electrospray emitter array

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.

Method and apparatus for an ion transfer tube and mass spectrometer system using same

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.

System for preventing backflow in an ion source

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).

Electro-dynamic or electro-static lens coupled to a stacked ring ion guide

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.

Ion transport device and modes of operation thereof

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.

Apparatus and method for providing ions to a mass analyzer

An ion guide having a plurality of spheroidal or similarly shaped electrodes is disclosed. The electrodes are arranged in pairs about a central ion flow axis, and an RF voltage is applied in a prescribed phase relation to create an electric field that focuses and radially confines an ion beam. A defocusing effect associated with the electrode shape may be reduced by placement of a separate skirt electrode immediately downstream in the ion path, or by forming the electrodes in a composite structure, whereby the trailing portion of the electrode is fabricated from or coated with an insulative material.

Multipole ion guide having longitudinally rounded electrodes

An ion source includes an ion transfer tube having two segments for transporting a sample fluid containing ions between a first chamber and a second chamber maintained at a reduced pressure relative to the first chamber. A first segment may include a plurality of channels and heat conductive walls forming the plurality of channels. The plurality of channels and walls forming the channels promote efficient convective heat transfer to the sample fluid, thereby enabling operation at relatively high sample fluid flow rates, resulting in an increase in the number of ions that may be delivered to a mass analyzer. A second segment forms a single common channel that receives a plurality of sample streams and enables them to combine into a single ion stream that may be introduced as a single gas stream expansion into the second chamber.

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Walnut Creek, CA, United States of America

Maurizio Splendore