Energy resolved time-of-flight mass spectrometry

Patent metadata

Field	Value
Publication number	US-2016284531-A1
Application number	US-201514671521-A
Country	US
Kind code	A1
Filing date	Mar 27, 2015
Priority date	Mar 27, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

A time-of-flight mass spectrometer (TOF-MS) utilizes an ion dispersion device and a position-sensitive ion detector or an energy-sensitive ion detector to enable measurement of time of flight and kinetic energy of ions arriving at the detector. The measurements may be utilized to improve accuracy in calculating ion masses.

First claim

1 . A time-of-flight mass spectrometry (TOF-MS) system, comprising:
an ion source; a TOF analyzer comprising an ion accelerator, a flight region, and an ion detector comprising a plurality of channels; an ion dispersion device configured for dispersing ions from the ion source into a plurality of spatially separated ion beams based on different kinetic energies of the ions, wherein ions of different kinetic energies travel in the flight region in spatially separated flight paths and respective channels are aligned with the flight paths; and a computing device configured for: receiving an ion measurement signal from the ion detector corresponding to detection of an ion; determining a time of flight and a kinetic energy of the ion based on the ion measurement signal; and calculating a mass of the ion by applying a mass calibration function based on the time of flight, the kinetic energy, and one or more instrument-dependent calibration constants.

2 . The TOF-MS system of claim 1 , wherein the ion dispersion device is positioned upstream of the ion accelerator, at the ion accelerator, or in the flight region.

3 . The TOF-MS system of claim 1 , wherein the ion dispersion device is positioned upstream of the ion accelerator, and the ion accelerator is configured for receiving the spatially separated ion beams simultaneously and accelerating ions from the spatially separated ion beams into the flight region along the spatially separated flight paths.

4 . The TOF-MS system of claim 1 , wherein the ion dispersion device is positioned upstream of the ion accelerator, and the ion accelerator comprises a plurality of ion accelerators, each ion accelerator configured for receiving one or more of the ion beams.

5 . The TOF-MS system of claim 1 , wherein the ion dispersion device is positioned at the ion accelerator, and the ion accelerator is configured for receiving a primary ion beam and accelerating ions dispersed by the ion dispersion device into the flight region along the spatially separated flight paths.

6 . The TOF-MS system of claim 1 , wherein the ion dispersion device is positioned in the flight region, and is configured for receiving ions traveling in an initial flight path from the ion accelerator and dispersing the ions into the spatially separated flight paths.

7 . The TOF-MS system of claim 1 , wherein the ion dispersion device comprises an ion deflector, an ion mirror, an electrostatic sector instrument, an energy-analysis sector instrument, or a combination or two or more of the foregoing.

8 . The TOF-MS system of claim 1 , wherein the ion dispersion device comprises a plurality of ion dispersion devices arranged such that each ion dispersion device receives the ions outputted from a preceding ion dispersion device or outputs ions to a succeeding ion dispersion device.

9 . (canceled)

10 . A time-of-flight mass spectrometry (TOF-MS) system, comprising:
an ion source; a TOF analyzer comprising an ion accelerator, a flight region, and an energy-sensitive ion detector, wherein the energy-sensitive ion detector is configured for both detecting arrival times of ions and measuring kinetic energy of the ions; and receiving an ion measurement signal from the ion detector corresponding to detection of an ion; determining a time of flight and a kinetic energy of the ion based on the ion measurement signal; and calculating a mass of the ion by applying a mass calibration function based on the time of flight and the kinetic energy.

11 . The TOF-MS system of claim 10 , wherein the energy-sensitive ion detector is configured for measuring secondary excitations created in response to arrival of an ion at the energy-sensitive ion detector.

12 . (canceled)

13 . A method for performing time-of-flight mass spectrometry (TOF-MS), the method comprising:
receiving an ion measurement signal from an ion detector of a TOF analyzer corresponding to detection of an ion; determining a time of flight and a kinetic energy of the ion based on the ion measurement signal; and calculating a mass of the ion by applying a mass calibration function based on the time of flight, the kinetic energy, and one or more instrument-dependent calibration constants.

14 . The method of claim 13 , comprising:
before receiving the ion measurement signal,
dispersing ions into a plurality of spatially separated ion beams based on different kinetic energies of the ions; and
transmitting the ions to the ion detector, wherein ions of different kinetic energies arrive at different positions on the ion detector,
and further comprising correlating the positions with respective kinetic energies.

15 . The method of claim 14 , comprising transmitting the ions into an ion accelerator of the TOF analyzer and operating the ion accelerator to accelerate the ions into a flight region of the TOF analyzer, wherein dispersing the ions is performed before transmitting the ions into the ion accelerator, or at the ion accelerator, or in the flight region after accelerating the ions.

16 . The method of claim 14 , wherein dispersing the ions comprises operating an ion dispersion device comprising an ion deflector, an ion mirror, an electrostatic sector instrument, an energy-analysis sector instrument, or a combination or two or more of the foregoing.

17 . The method of claim 14 , wherein dispersing the ions comprises operating a plurality of ion dispersion devices arranged such that each ion dispersion device receives the ions outputted from a preceding ion dispersion device or outputs ions to a succeeding ion dispersion device.

18 . The method of claim 13 , wherein the ion detector is an energy-sensitive ion detector configured for both detecting arrival times of ions and measuring kinetic energy of the ions.

19 . The method of claim 18 , wherein the energy-sensitive ion detector is configured for measuring secondary excitations created in response to arrival of an ion at the energy-sensitive ion detector.

20 . A system for acquiring spectral data from a sample, the system comprising: a processor and a memory configured for performing the method of claim 13 .

21 . A time-of-flight mass spectrometry (TOF-MS) system, comprising:
an ion source; a TOF analyzer comprising an ion accelerator, a flight region, and an ion detector comprising a plurality of channels; and an ion dispersion device configured for dispersing ions from the ion source into a plurality of spatially separated ion beams based on different kinetic energies of the ions, wherein ions of different kinetic energies travel in the flight region in spatially separated flight paths and respective channels are aligned with the flight paths, and wherein the ion dispersion device has a configuration selected from the group consisting of: the ion dispersion device is positioned upstream of the ion accelerator, and the ion accelerator is configured for receiving the spatially separated ion beams simultaneously and accelerating ions from the spatially separated ion beams into the flight region along the spatially separated flight paths; the ion dispersion device is positioned upstream of the ion accelerator, and the ion accelerator comprises a plurality of ion accelerators, each ion accelerator configured for receiving one or more of the ion beams; the ion dispersion device is positioned at the ion accelerator, and the ion accelerator is configured for receiving a primary ion beam and accelerating ions dispersed by the ion dispersion device into the flight region alo

Assignees

• Agilent Technologies Inc

Inventors

• Zaks Julia
• Ristroph Trygve

Classifications

• H01J49/06

  Electron- or ion-optical arrangements · CPC title

• H01J49/0027

  Methods for using particle spectrometers · CPC title

• H01J49/401 Primary

  characterised by orthogonal acceleration, e.g. focusing or selecting the ions, pusher electrode · CPC title

• H01J49/40 Primary

  Time-of-flight spectrometers (H01J49/36 takes precedence) · CPC title

• H01J49/025

  Detectors specially adapted to particle spectrometers (data acquisition H01J49/0036; detectors per se G01T, e.g. G01T1/28, G01T1/29) · CPC title