Thermo Finnigan LLC

Satendra Prasad

Michael William Belford

Jean-Jacques Dunyach

Eloy R Wouters

Jean Jacques Dunyach

R Paul Atherton

Bennett S Kalafut

Dhruva D Kulkarni

Adjusting compensation voltage (CV) parameters of an ion mobility device is described. In one instance, the CV parameters are adjusted to reflect a different CV range, a number of CV steps, or a CV step size to increase throughput of a mass spectrometer.

Compensation voltage adjustment for ion mobility separation

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 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 method for transmitting ions entrained in a flowing carrier gas into and through a gap defined by a pair of mutually facing curved electrodes comprises: inputting the ions and flowing gas into the gap through an ion inlet orifice of a first one of the pair of electrodes, the ion inlet orifice comprising an orifice wall, an orifice inlet end and an orifice outlet end, the orifice wall being smoothly convexly curved between the inlet end and the outlet end, wherein a width of the gap and a flow rate of the carrier gas through the ion inlet orifice and gap are such that the gas flow is laminar within the ion inlet orifice and gap.

Method for transmitting ions and carrier gas between mutually facing curved electrodes

A High Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) apparatus comprises (a) a first and a second gas inlet; (b) an expansion chamber receiving ions from an ion source and the first and second gas flows from the first and second gas inlets, respectively; (c) an outer electrode having a generally concave inner surface and comprising: (i) an ion inlet operable to receive, from the expansion chamber, the ions and a combined gas flow comprising portions of the first and second gas flows; and (ii) an ion outlet; and (d) an inner electrode 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, wherein the combined gas flow and a portion of the ions travel through the ion separation region from the ion inlet to the ion outlet.

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San Jose, CA, United States of America

Satendra Prasad