Thermo Finnigan LLC

Other

Jean-Jacques Dunyach

Michael William Belford

Eloy R Wouters

Satendra Prasad

Mark E Hardman

Keqi Tang

Alan E Schoen

Maurizio Splendore

R Paul Atherton

Michael W Senko

Jae C Schwartz

Philip M Remes

Nigel P Gore

Rohan A Thakur

Berg A Tehlirian

Paul R Atherton

Using ion mobility separation to improve a duty cycle of a mass spectrometer is described. In one aspect, a mass spectrometer can use an ion-mobility spectrometer to allow for more multiply-charged ions to transmit through than singly-charged ions. This results in a mass analyzer to perform a mass analysis with more multiply-charged ions.

Duty cycle improvement for a mass spectrometer using ion mobility separation

A FAIMS device interfaces between an ionization source and a mass spectrometer. The FAIMS device includes inner and outer electrodes having radially opposed surfaces, which define there between a gap through which ions are transported. A waveform generator is configured to apply a selected one of two distinct periodic waveforms to the electrodes, consisting of: a first waveform characterized by equal high and low amplitudes and periods and a second waveform including a bi-sinusoidal waveform superimposed with a DC compensation voltage. The device is configured to toggle between a transmission mode of operation in which ions are passed through the device with no spatial separation when the first waveform is applied to the inner and/or outer electrodes and a separation mode of operation in which spatial separation of the ions occurs in the gap when the bi-sinusoidal waveform and DC voltage are applied to the inner and/or outer electrodes.

FAIMS device for separation or transmission of ions

A system for transporting ions includes: an ion transfer tube having an axis and an internal bore having a width and a height less than the width; and an apparatus comprising a plurality of electrodes, each having a respective ion aperture having an aperture center, the apertures defining an ion channel configured to receive the ions from the ion transfer tube and to transport the ions to an outlet end of the apparatus, wherein at least a subset of the apertures progressively decrease in size in a direction towards the apparatus outlet end, wherein the ion transfer tube is configured such that the ion transfer tube axis is non-coincident with an axis of the ion channel or such that the width dimension of the ion transfer tube bore is parallel to a plane defined by the ion transfer tube axis and the ion channel axis.

System for transferring ions in a mass spectrometer

A method of operating a system comprising a chromatograph and a mass spectrometer comprises: (a) providing an abundance threshold and a list comprising respective entries for precursor ion species of interest comprising respective precursor-ion m/z ratios; (b) transmitting a first sample fraction portion comprising a plurality of sample-fraction ion species through an ion mobility spectrometer operated in non-dispersive mode to the mass spectrometer; (c) detecting a respective abundance at each of a plurality of sample-fraction m/z ratios; and (d) upon detection of an above-threshold ion abundance at an m/z-ratio corresponding to a first precursor ion species of interest: (d1) inletting a second sample fraction portion into the ion mobility spectrometer operated in dispersive mode such that ions of the first precursor-ion species are preferentially transmitted therethrough; (d2) fragmenting the preferentially-transmitted ions so as to generate product ion species; and (d3) detecting the product ion species.

System comprising a mass spectrometer coupled to a FAIMS apparatus and methods of operation

A method is described for identifying the occurrence and location of charging of ion optic devices arranged along the ion path of a mass spectrometer. The method includes repeatedly performing a sequence of introducing a beam of discharge ions to a location on the ion path, and subsequently measuring the intensities of opposite-polarity sample ions delivered to a mass analyzer, with the discharge ions being delivered to a location further downstream in the ion path at each successive sequence.

Identifying the occurrence and location of charging in the ion path of a mass spectrometer

A method for transporting ions within a mass spectrometer comprises: inputting the ions and neutral molecules to a first end of an ion transport apparatus comprising a plurality of non co-planar ring-shaped electrode portions having respective central apertures having centers that lie along a common axis and that define an ion channel, the radii of the central apertures decreasing in a direction from the first end to a second end of the ion transport apparatus; applying a set of Radio Frequency voltages to the plurality of electrode portions such that the ions remain substantially confined to the ion channel while passing from the first to the second end; and exhausting the neutral molecules from the ion transport apparatus though a plurality of channels or apertures other than the apertures that define the ion channel, the exhausting performed in one or more directions that are non-perpendicular to the axis.

Radio frequency device to separate ions from gas stream and method thereof

A ion source for a mass spectrometer comprises: a capillary having a nozzle for emitting a nebulized fluid sample; an electrode of the capillary; a high voltage power supply; a second electrode disposed within or configurable to be disposed within a path of the nebulized fluid sample; and at least one switch for selecting application of an electrical potential provided by the high voltage power supply to either or both of the capillary electrode or the second electrode, wherein the capillary and capillary electrode are configurable so as to ionize the nebulized fluid sample by electrospray ionization and the second electrode is configurable so as to ionize the nebulized sample by atmospheric pressure chemical ionization.

Interchangeable ion source for electrospray and atmospheric pressure chemical ionization

A system for analyzing ions comprises: an ion source; a FAIMS cell comprising: (a) a gas inlet; (b) an outer electrode having a generally concave inner surface and comprising: (i) an ion inlet operable to receive the ions from the ion source and a carrier gas from the gas inlet; and (ii) an ion outlet; and (c) an inner electrode having a conduit therethrough and having a generally convex outer surface disposed in a spaced-apart and facing arrangement relative to the inner surface of the outer electrode defining at least one annular on separation region therebetween; and a mass analyzer for mass analyzing ions transmitted by the FAIMS cell through the ion outlet, wherein the inner electrode is moveable between a first position and a second position, the first and second positions facilitating movement of the ions through the at least one annular ion separation region and the conduit, respectively.

FAIMS having a displaceable electrode for on/off operation

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

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 system for analyzing ions comprises: an ion source; a FAIMS cell comprising: (a) a gas inlet; (b) an outer electrode having a generally concave inner surface and comprising: (i) an ion inlet operable to receive the ions from the ion source and a carrier gas from the gas inlet; and (ii) an ion outlet; and (c) an inner electrode having a conduit therethrough and having a generally convex outer surface that is disposed in a spaced-apart and facing arrangement relative to the inner surface of the outer electrode for defining an ion separation region therebetween; and a mass analyzer for mass analyzing ions transmitted by the FAIMS cell through the ion outlet, wherein the inner electrode is moveable between a first position and a second position, the first position facilitating movement of the ions through the ion separation region, the second position facilitating movement of the ions through the conduit.

There is described an interface for delivering ions generated in an ion source into a mass analyzer in a chamber under vacuum pressure. In particular, the interface employs two consecutive ion guides operated to dissociate adduct ions formed in the ion source or high pressure regions of the interface between the ion source and the mass analyzer, thus improving the limit of detection or limit of quantitation of the mass analyzer by increasing the analyte ion current. The questions raised in reexamination request no. 90/007,724, filed Sep. 16, 2005 have been considered and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1.570(e), for ex parte reexaminations, or the reexamination certificate required by 35 U.S.C. 316 as provided in 37 CFR 1.997(e) for inter partes reexaminations.

Mass spectrometer system including a double ion guide interface and method of operation

An on-axis ion source has an ionization chamber and an adjacent low-pressure region. The on-axis ion source also includes a capillary tube having an axial bore for supporting fluid communication between the ionization chamber and the adjacent low-pressure region, the axial bore of the capillary tube being substantially concentrically aligned with the orifice of a skimmer located downstream in the ion path from the capillary tube. A blocking element is provided in an aligned facing arrangement with the axial bore of the capillary tube and on an opposite side of the orifice relative to the capillary tube. The blocking element receives droplets or particles flowing through the axial bore of the capillary tube and passing through the orifice of the skimmer. The combination of an on-axis arrangement and the use of a blocking element results in improved signal-to-noise level due to enhanced ion transmission and reduction of noise arising from passage of undesolvated droplets and particles to the mass analyzer.

Electrospray ion source

There is described an interface for delivering ions generated in an ion source into a mass analyzer in a chamber under vacuum pressure. In particular, the interface employs two consecutive ion guides operated to dissociate adduct ions formed in the ion source or high pressure regions of the interface between the ion source and the mass analyzer, thus improving the limit of detection or limit of quantitation of the mass analyzer by increasing the analyte ion current.

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San Jose, CA, United States of America

Jean-Jacques Dunyach