Shimadzu Corporation

Tomoyuki Oshiro

Daisuke Okumura

Osamu Furuhashi

Yuta Miyazaki

Shiro Mizutani

Hiroaki Kozawa

Yoshikatsu Umemura

Kazuma Maeda

Kosuke Uchiyama

Provided is a TOFMS having a measurement unit in which target ions are accelerated and sent into a flight space within which an electric field for causing ions to fly is created. A data-analysis processor () creates a spectrum based on data acquired by the measurement unit, where the spectrum shows a relationship between ion intensity and time-of-flight or m/z value. An index calculator () calculates, as an index concerning a peak in the spectrum, a time-of-flight or m/z-value difference between a midpoint of a first peak width at an intensity which equals the peak-top intensity multiplied by a first ratio and a midpoint of a second peak width at an intensity which equals the peak-top intensity multiplied by a second ratio smaller than the first ratio. An evaluation result storage section () evaluates the peak symmetry from the index and stores an evaluation result.

Time-of-flight mass spectrometer and tuning method for the same

An analytical device includes: a first acceleration unit including a first acceleration electrode to which a pulse voltage for accelerating ions is applied; a flight tube; a second acceleration unit that is arranged between the first acceleration unit and the flight tube, and includes a second acceleration electrode to which a voltage for accelerating the ions is applied; an ion detector that detects the ions; and a capacitance adjustment unit that causes adjustment of a capacitance between at least one set of electrodes among a plurality of electrodes arranged in the first acceleration unit, the second acceleration unit, and a flight tube.

Analytical device

An analytical device includes: a mass spectrometry unit that separates ions based on flight time and detects the ions having been separated; an analysis unit that creates data corresponding to a spectrum in which an intensity of the ions having been detected and the flight time or m/z corresponding to the flight time are associated; a peak width calculation unit that calculates a first peak width at a first intensity and a second peak width at a second intensity different from the first intensity for at least one peak in the spectrum; and an adjustment unit that performs an adjustment of the mass spectrometry unit based on the first peak width and the second peak width.

Analytical device, analysis method and program

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.

Time-of-flight mass spectrometer

For an automatic adjustment of a detector voltage, a measurement of a standard sample is performed, in which a reflection voltage generator under the control of an autotuning controller applies, to a reflector, voltages which are different from those applied in a normal measurement and do not cause temporal conversion of ions. Ions having the same m/z simultaneously ejected from an ejector are dispersed in the temporal direction and reach a detector. Therefore, a plurality of low peaks corresponding to individual ions are observed on a profile spectrum. A peak-value data acquirer determines a wave-height value of each peak. A wave-height-value list creator creates a list of wave-height values. A detector voltage determiner searches for a detector voltage at which the median of the wave-height values in the wave-height-value list falls within a reference range.

A multipole ion guide () including a plurality of rod electrodes arranged at an angle to the central axis (C) is placed within a collision cell () located in the previous stage of an orthogonal accelerator (). Radio-frequency voltages with opposite phases are applied to the rod electrodes of the ion guide () so that any two rod electrodes neighboring each other in the circumferential direction have opposite phases of the voltage. A depth gradient of the pseudopotential is thereby formed from the entrance end toward the exit end within the space surrounded by the rod electrodes, and ions are accelerated by this gradient. During an ion-accumulating process, a direct voltage having the same polarity as the ions is applied to the exit lens electrode () to form a potential barrier for accumulating ions. Among the ions repelled by the potential barrier, ions having smaller m/z return closer to the entrance end. Therefore, when the potential barrier is removed and ions are discharged, ions having smaller m/z are discharged at later points in time than those having larger m/z. Therefore, a wide m/z range of ions can be simultaneously accelerated and ejected by an orthogonal accelerator ().

Orthogonal acceleration time-of-flight mass spectrometry

An orthogonal acceleration time-of-flight (TOF) mass spectrometer in which an ion injected into an orthogonal acceleration area is periodically accelerated in a direction orthogonal to a direction of the injection and thereby ejected into a flight space. The mass spectrometer includes: an orthogonal acceleration electrode; a voltage supplier for applying a fixed level of voltage to the orthogonal acceleration electrode with a predetermined period; a TOF determiner for detecting an ion after a completion of a flight of the ion within the flight space, and determining the TOF of the ion; a storage section in which mass determination information defining a relationship between the TOF and mass-to-charge ratio of the ion depending on the period of the applied voltage is stored; and a mass-to-charge-ratio determiner for determining the mass-to-charge ratio of an ion from the TOF of the ion determined by the TOF determiner, based on the mass determination information.

Voltages are applied by a voltage application device having an electrode circuit including a plurality of electrode connection parts connected in series via a resistance R between neighboring electrode connection parts; and power sources P for outputting both positive and negative polarities, each power source connected to both ends of the electrode circuit. The method of applying a voltage includes determining a polarity and a magnitude of an output voltage of so that a voltage having a predetermined polarity and magnitude is applied to the electrodes; and based on the polarities, switching the polarities of the output voltages by switching the polarities of the output voltages of the plurality of power sources P one at a time while maintaining a state where a polarity of an output voltage of at least one power source P, among the plurality of power sources P, is different from others.

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Kyoto, Japan

Tomoyuki Oshiro