# US 2021/0242008 A1 · Time-of-flight mass spectrometer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0242008 A1 - Document ID: US20210242008A1 - Status: Published application - Kind: A1 - Application number: 17/052,570 - Filed: 2018-05-14 - Published: 2021-08-05 - Earliest claimed: 2018-05-14 - Assignees: Shimadzu Corporation - Applicants: Shimadzu Corporation - Inventors: Tomoyuki OSHIRO; Yoshikatsu UMEMURA; Kazuma MAEDA - Web page: https://patentgrep.com/patent/US20210242008A1 ## CPC - H01J 49/40: Time-of-flight spectrometers (H01J49/36 takes precedence) - H01J 49/4215: {Quadrupole mass filters (H01J49/4225 takes precedence)} - H01J 49/0031: {Step by step routines describing the use of the apparatus (H01J49/0081 takes precedence)} - H01J 49/0045: {characterised by the fragmentation or other specific reaction} - H01J 49/022: {Circuit arrangements, e.g. for generating deviation currents or voltages (regulating electric or magnetic variables in general, e.g. current, magnetic field G05F); Components associated with high voltage supply (high voltage supply per se H02M)} - H01J 49/062: {Ion guides (linear ion traps performing mass selection H01J49/4225, mass filters H01J49/421)} - H01J 49/063: {Multipole ion guides, e.g. quadrupoles, hexapoles} - H01J 49/165: {Electrospray ionisation} - H01J 49/401: {characterised by orthogonal acceleration, e.g. focusing or selecting the ions, pusher electrode} - H01J 49/429: {Scanning an electric parameter, e.g. voltage amplitude or frequency} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract To acquire a mass spectrum for a wide mass range, a normal analysis execution controlling unit controls components to repeatedly perform measurement while changing setting m/z by a predetermined m/z at a time, and a mass spectrum summarizing processing unit summarizes data pieces each obtained by each time of measurement to generate the mass spectrum. Radio-frequency voltage applied to an ion guide and the like is changed based on the setting m/z. The radio-frequency voltage for the setting m/z is determined using a table in which a relationship between a position on an axis between upper and lower limits of the mass range and the radio-frequency voltage is substantially the same regardless of the mass range. ## Claims ### Claim 1 A time-of-flight mass spectrometer including an ion source for ionizing a sample component, a time-of-flight mass spectrometry unit including an ion ejecting unit for ejecting ions generated by the ion source or other ions derived from the generated ions into a flight space, and one or a plurality of ion transport optical elements for transporting the ions while focusing the ions by means of a radio-frequency electric field, the one or plurality of ion transport optical elements being provided between the ion source and the ion ejecting unit, the time-of-flight mass spectrometer comprising: a) a voltage generating unit for applying radio-frequency voltage for forming the radio-frequency electric field to each of the one or plurality of ion transport optical elements; b) a controlling unit for determining, in response to a mass range designated as an observation target, a radio-frequency voltage applied to each of the one or plurality of ion transport optical elements in each of a plurality of times of measurement using different measurement target mass-to-charge ratio ranges for acquiring a mass spectrum entirely covering a mass-to-charge ratio range of the mass range, and for controlling components to perform the plurality of times of measurement while changing the radio-frequency voltage applied to each of the one or plurality of ion transport optical elements by the voltage generating unit, the controlling unit determining the radio-frequency voltage for each of the plurality of times of measurement to maintain a ratio of times of measurement in which radio-frequency voltage is set so that ion passage efficiency in a low mass-to-charge ratio region is relatively high among the plurality of times of measurement to be substantially constant regardless of a width of the mass range; and c) a mass spectrum summarizing processing unit for obtaining a mass spectrum corresponding to the mass range by summarizing mass spectrum data pieces obtained by the plurality of respective times of measurement under control by the controlling unit. ### Claim 2 (depends on 1) The time-of-flight mass spectrometer according to claim 1, wherein the controlling unit determines the radio-frequency voltage based on a table or a formula in which a relationship between a position on an axis between upper and lower limits of the mass range and the radio-frequency voltage is substantially same between different mass ranges. ### Claim 3 (depends on 1) The time-of-flight mass spectrometer according to claim 1, wherein a quadrupole mass filter capable of selectively allowing ions with a certain mass-to-charge ratio to pass through and a collision cell for dissociating the ions are provided between the ion source and the ion ejecting unit, and the quadrupole mass filter operating without selecting the ions and an ion guide provided in the collision cell collectively serve as one of the one or plurality of ion transport optical elements. ### Claim 4 (depends on 3) The time-of-flight mass spectrometer according to claim 3, wherein one or a plurality of ion guides provided between the ion source and the quadrupole mass filter serve as the one or plurality of ion transport optical elements. ### Claim 5 (depends on 2) The time-of-flight mass spectrometer according to claim 2, wherein a quadrupole mass filter capable of selectively allowing ions with a certain mass-to-charge ratio to pass through and a collision cell for dissociating the ions are provided between the ion source and the ion ejecting unit, and the quadrupole mass filter operating without selecting the ions and an ion guide provided in the collision cell collectively serve as one of the one or plurality of ion transport optical elements.