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EP-4738423-A1 - MASS SPECTROMETER AND CALIBRATION METHOD FOR MASS SPECTROMETER

EP4738423A1EP 4738423 A1EP4738423 A1EP 4738423A1EP-4738423-A1

Abstract

Provided are a mass spectrometer and a calibration method for a mass spectrometer capable of performing calibration more easily than one in the related art. A mass spectrometer 100 according to the present embodiment described above includes: an ion source 101 configured to ionize a sample; a detection unit 105 including a photomultiplier tube 105a and configured to analyze a mass of the sample ionized by the ion source 101; a vacuum chamber 102 configured to allow the ion source 101 to communicate with the detection unit 105; a vacuum gauge 106 configured to measure a vacuum degree inside the vacuum chamber 102; and a data analysis unit 112 and an analysis control unit 113 configured to calibrate setting of the photomultiplier tube 105a using electrons emitted from the vacuum gauge 106.

Inventors

  • TOMA Tsugunao
  • TAMURA Riku
  • YOSHIE MASAKI
  • YASUDA HIROYUKI
  • SUGIYAMA MASUYUKI
  • HASHIMOTO YUICHIRO

Assignees

  • HITACHI HIGH-TECH CORPORATION

Dates

Publication Date
20260506
Application Date
20240523

Claims (6)

  1. A mass spectrometer comprising: an ion source configured to ionize a sample; a mass spectrometry unit including a photomultiplier tube and configured to analyze a mass of the sample ionized by the ion source; a vacuum chamber configured to allow the ion source to communicate with the mass spectrometry unit; a vacuum gauge configured to measure a vacuum degree inside the vacuum chamber; and a calibration unit configured to calibrate setting of the photomultiplier tube using electrons emitted from the vacuum gauge.
  2. The mass spectrometer according to claim 1, wherein the vacuum gauge is of an ionization type.
  3. The mass spectrometer according to claim 1, wherein the calibration unit performs calibration at a timing when analysis is not performed in the mass spectrometry unit.
  4. The mass spectrometer according to claim 1, wherein the calibration unit sets setting of the mass spectrometry unit at a time of the calibration to setting for measurement of negative ions.
  5. The mass spectrometer according to claim 1, further comprising: a display device configured to display a screen for setting a condition at a time of the calibration.
  6. A calibration method for a mass spectrometer, the mass spectrometer including an ion source configured to ionize a sample, a mass spectrometry unit including a photomultiplier tube and configured to analyze a mass of the sample ionized by the ion source, a vacuum chamber configured to allow the ion source to communicate with the mass spectrometry unit, and a vacuum gauge configured to measure a vacuum degree inside the vacuum chamber, the calibration method for a mass spectrometer comprising: calibrating setting of the photomultiplier tube using electrons emitted from the vacuum gauge.

Description

Technical Field The present invention relates to a mass spectrometer and a calibration method for a mass spectrometer. Background Art PTL 1 describes a mass spectrometer that includes a gas injection port adapted to supply a sample gas to be ionized to an ionization region of the mass spectrometer, a calibration unit adapted to supply a calibration gas to be ionized to the ionization region, and an ionization unit adapted to ionize the sample gas and/or the calibration gas in the ionization region, in which the calibration unit includes at least one evaporation source that generates the calibration gas by evaporating a raw material. Citation List Patent Literature PTL 1: JP2022-553543A Summary of Invention Technical Problem The mass spectrometer includes an ion source that ionizes a compound in a sample, a mass spectrometry unit such as a mass filter that separates ions derived from the compound according to a mass-to-charge ratio (m/z), and a detector that detects the separated ions. PTL 1 describes that in the mass spectrometer provided with a vacuum chamber that allows the ion source to communicate with the mass spectrometry unit, an ionization type vacuum gauge that measures a vacuum degree inside the vacuum chamber is provided, and the vacuum gauge is operated at a timing when measurement is not being performed in the mass spectrometry unit to calibrate the detector of the mass spectrometry unit using the calibration gas. Thus, it is necessary to ionize and introduce the sample in order to calibrate the detector of the mass spectrometer. However, since it is necessary to ionize the sample when the detector is calibrated, a technique capable of performing calibration more efficiently has been awaited. The invention provides a mass spectrometer and a calibration method for a mass spectrometer that are capable of performing calibration more easily as compared with the related art. Solution to Problem The invention includes a plurality of means for solving the above problems, and an example thereof includes: an ion source configured to ionize a sample; a mass spectrometry unit including a photomultiplier tube and configured to analyze a mass of the sample ionized by the ion source; a vacuum chamber configured to allow the ion source to communicate with the mass spectrometry unit; a vacuum gauge configured to measure a vacuum degree inside the vacuum chamber; and a calibration unit configured to calibrate setting of the photomultiplier tube using electrons emitted from the vacuum gauge. Advantageous Effects of Invention According to the invention, it is possible to perform calibration more easily as compared with the related art. Problems, configurations, and effects other than those described above will be clarified by the following description of an embodiment. Brief Description of Drawings [FIG. 1] FIG. 1 is a diagram showing an overall configuration of a mass spectrometer.[FIG. 2] FIG. 2 is a flowchart of voltage adjustment of a photomultiplier tube.[FIG. 3] FIG. 3 is a sequence diagram of a voltage adjustment set of the photomultiplier tube.[FIG. 4] FIG. 4 is a sequence diagram of voltage adjustment of the photomultiplier tube.[FIG. 5] FIG. 5 is a diagram showing an example of display of a software GUI screen for voltage adjustment of the photomultiplier tube. Description of Embodiments Embodiments of a mass spectrometer and a calibration method for a mass spectrometer according to the invention will be described with reference to FIGS. 1 to 5. In the drawings used in the present specification, the same or corresponding components are denoted by the same or similar reference signs, and repeated descriptions of these components may be omitted. First, an overall configuration of a mass spectrometer will be described with reference to FIG. 1. FIG. 1 is a diagram showing an overall configuration of the mass spectrometer. A mass spectrometer 100 shown in FIG. 1 includes an ion source 101, a vacuum chamber 102 having an ion transport section 103, a mass separation unit 104, and a detection unit 105, a vacuum gauge 106, an A/D conversion unit 111, a data analysis unit 112, an analysis control unit 113, a display device 114, and the like. The ion source 101 is a portion that ionizes a sample. Inside of the vacuum chamber 102 is evacuated by a pump to transport the sample ionized by the ion source 101 to the detection unit 105, and the ion transport section 103, the mass separation unit 104, the detection unit 105, and the vacuum gauge 106 are disposed inside the vacuum chamber 102. The ion transport section 103 is a portion that transports ions ionized by the ion source 101 and introduced into the vacuum chamber 102 toward the mass separation unit 104 or the detection unit 105 on a subsequent stage side. The mass separation unit 104 is a device such as a mass filter that separates a compound in the ionized sample according to a mass-to-charge ratio (m/z). The detection unit 105 is a portion that analyzes a mas