Shimadzu Corporation

Kobe University

Osamu Furuhashi

Kiyoshi Ogawa

Tohru Kinugawa

Daisuke Okumura

Junichi Taniguchi

Hideaki Izumi

Tomoyuki Oshiro

Shinichi Yamaguchi

Masaru Nishiguchi

Shigeki Kajihara

Takahiro Harada

Kengo Takeshita

Mitsutoshi Setou

Yoshikazu Yoshida

Akiko Imazu

Tomomi Tamura

Shuichi Shimma

Sadao Takeuchi

Yoshinori Arita

Ding Li

In order to improve the ionization efficiency and ion collection efficiency in an ESI ion source to achieve a higher level of analysis sensitivity while improving the throughput of the analysis, one mode of the present invention provides an ion analyzer equipped with an ion source employing an electrospray ionization method, where the ion source () includes: a plurality of capillaries (-) configured to spray a supplied liquid sample in the same direction; one or more auxiliary electrodes (-) arranged so as to be surrounded by the plurality of capillaries; and a voltage supplier () configured to apply, to the plurality of capillaries, a DC high voltage for which the potential of the one or more auxiliary electrodes is used as a reference.

Ion analyzer

A mass spectrometer () includes: an ionization section () configured to generate ions from a sample; a mass separation section () configured to separate ions generated by the ionization section according to mass-to-charge ratio; an ion detector () configured to detect an ion separated by the mass separation section; an ion capture section () configured to capture ions separated by the mass separation section; and an electron beam detection section () configured to detect an electron beam diffracted by ions captured within the ion capture section (). This mass spectrometer is capable of performing, in a single measurement operation, both a mass spectrometric analysis and an electron-beam diffraction measurement for distinguishing between isomers. The electron-beam diffraction measurement can be more efficiently performed than in a conventional device of this type.

Mass spectrometer

A mass spectrometer, includes: a sampling probe that irradiates a specimen disposed in the atmosphere with an electron and obtains a sample separated from the specimen; and a measurement unit that performs mass spectrometry of the sample obtained by the sampling probe, wherein the sampling probe comprises: a casing having an opening which is opened to the atmosphere and an outlet through which the sample is discharged to the measurement unit; and a surface emission type electron emission element housed in the casing such that an electron emission surface thereof opposes to the opening.

Mass spectrometer, sampling probe, and analysis method

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

The existence ratio of optical isomers (D-form, L-form) is easily measured. Counterclockwise or clockwise circularly polarized light is applied from a light application unitto ions which are derived from a target compound and are drifting in a drift region. The ions absorb light, and a collision cross-section of the ions thus changes, whereby the mobility also changes. Each of the D-form and the L-form has a light absorption rate which is different between counterclockwise circularly polarized light and clockwise circularly polarized light. Therefore, each light absorption rate is examined in advance, and an existence ratio of the D-form and the L-form is calculated, based on the two intensity ratios each of which is the ratio of a peak of the ions having absorbed no light and a peak of the ions having absorbed light, which peaks appear on a drift time spectrum, and based on the light absorption rates of the D-form and the L-form.

Method for analyzing optical isomers using circularly polarized light and ion mobility analyzer

An ion reflector has a configuration in which multiple plate electrodes having a rectangular opening are arranged. The components are arranged so that a central axial line extending in the longitudinal direction of the opening lies on a plane which contains a straight line (Y-axis) connecting the centroidal position of an ion distribution in an ion trap and a central position on the detection surface of a detector, and a central axial line (X-axis) of an ion-ejecting direction. If the potential distribution along the central axis of the ion reflector is modified so that a portion of the reflecting field becomes a non-uniform electric field intended for improving isochronism for a group of ions to be detected, an area having an ideal potential distribution for realizing the isochronism is spread in the Y-axis direction.

Time-of-flight mass spectrometer

Used as an ion beam guiding unit for introducing primary ions to the surface of the sample is an ion optical system of reflectron TOFMS for achieving time focusing including an orthogonal acceleration unit for accelerating the ions in the orthogonal direction, a flight space of a non-electric field, and an ion reflector for forming a reflecting electric field. A dual stage type is used as the ion reflector to superimpose the correction potential showing a predetermined non-linear potential distribution on the potential having a linear gradient of a uniform electric field at the side deeper than the second order focusing position that fulfills the Mamyrin solution, thereby correcting the temporal spread of ion packets emitted from the orthogonal acceleration unit until the deviation of third or higher order in energy, achieving high time focusing.

Ion radiation device and surface analyzer using said device

A first mass analysis is executed in a condition that gas is not introduced into a loop-flight chamber (), and a time-of-flight spectrum obtained in a data processor () is stored in a storage unit (). Next, a second mass analysis is executed on the same sample as the one used in the first mass analysis in a condition that a valve () is opened and helium gas (He) is introduced into the loop-flight chamber (), and the time-of-flight spectrum is obtained in the data processor (). If different kinds of ions having the same m/z value exit, these ions form a single peak in the first time-of-flight spectrum, while these ions appear as separate peaks in the second time-of-flight spectrum even though they have the same m/z value. This is because, in the second mass analysis, the ions collide with the gas and have different times of flight depending on their difference in size. A spectrum comparator () judges a change in the position or shape of the peak by comparing the two spectra, and outputs information relating to the difference in the size of the ions (the molecular structure, charge state, or molecular class of the ions), and the like. Accordingly, a wider variety of information than ever before can be provided.

Time-of-flight mass spectrometer for conducting high resolution mass analysis

In an ion reflector () configured from a plurality of electrodes, electrodesdisposed in a second stage region (S) for reflecting ions after deceleration are formed thinner than electrodes () disposed in a first stage region (S) for decelerating the ions. The thin electrodes suppress unevenness of potential, in particular, in a path away from the center axis of the reflector, which results in improvement of isochronism of an ion packet passing on the path. The thick electrodes () disposed in the first stage region (S) prevents stretching of the grid electrodes (G, G) from being affected, and unevenness of potential in the first stage region (S) hardly affects isochronism of the ions. By appropriately adjusting thicknesses and a pitch of the electrodes () adjacent to one another so as to align intervals between the electrodes (), it is possible to use spacers having the same size in common. Since the number of electrodes in the first stage region (S) can be reduced, an increase in costs is suppressed. Consequently, it is possible to bring an electric field of an ion reflection region closer to an ideal state and improve mass-resolving power while suppressing costs.

An electrostatic lens (), including five cylindrical electrodes (-) arrayed along an ion-optical axis (C) and an aperture plate () located on a common focal plane of two virtual convex lenses (Land L) formed under an afocal condition, is used as an ion-injecting optical system for sending ions into an orthogonal acceleration unit. The diameter of a restriction aperture () formed in the aperture plate () determines the angular spread of an exit ion beam. When voltages for making the electrostatic lens () function as an afocal system are set, a measurement with high mass-resolving power can be performed at a slight sacrifice of the sensitivity. When voltages for making the lens function as a non-afocal system having the highest ion-passage efficiency are set, a measurement with high sensitivity can be performed at a slight sacrifice of the resolving power.

A thin metal plate and two prismatic-bar-shaped metal members that are parallel to each other are alternately and repeatedly stacked, and the stack is sandwiched between two thick metal plates. Each contact surface is bonded to the counterpart surface by diffusion bonding to form an integrated multilayer body. The multilayer body is cut at predetermined intervals at planes perpendicular to the thin metal plates, whereby a grid-like electrode is completed, with the thin metal plates serving as crosspieces and the metal members serving as spacers for defining a gap which serves as openings.

An embodiment with a dual-stage reflectron is as follows: (1) On the assumption that a reflector has a base potential X(U) created by uniform electric fields, its design parameters are adjusted so as to cancel the first and second order derivatives at energy E=Eof a total time of flight T(E), and a second-order focusing position on a central axis at which the potential value becomes zero is determined (Mamyrin solution). (2) A correcting potential X(U) to be superposed on X(U), beginning from the second-order focusing position, is calculated so that T(E) of ions reflected in a region deeper than the second-order focusing position will be constant. (3) Voltage values of the reflector electrodes are determined so that a real potential X(U)=X(U)+X(U) is created on the central axis.

A method creates an accurate mass spectrum with a high resolving power based on a plurality of TOF spectra, while reducing the computation to assure real-time processing. TOF spectra are measured when ions are ejected from the loop orbit. Then a coincidence detection method determines what mass-to-charge ratio a peak appearing on the TOF spectra originates from. The time range in which a corresponding peak appears on other TOF spectra is set, and the existence of the peak in that range is determined. When the corresponding peak is found on other TOF spectra, the m/z is deduced from the peak on the TOF spectrum with the highest resolving power and a mass spectrum is created. From the peak density around the peak of interest, the reliability of the deduction is computed. For a low reliability peak, the ion ejection time is optimized and the TOF spectrum is measured again.

Mass analysis data processing method and mass spectrometer

A multi-turn time-of-flight mass spectrometer creates, an accurate mass spectrum of a wide mass range, with the smallest number of measurements. Deflecting electrodes are provided on an ejection path through which ions deviating from a loop orbit fly to a detector having two-dimensional array elements. A varying voltage applied to the deflecting electrodes creates an electric field. When two ions having different mass-to-charge ratios simultaneously arrive at the detector, these ions are affected with differing strengths since they pass through the deflecting electric field at different times. This results in arrival for the ions on a detection surface. The time an ion passing through the deflecting electric field can be calculated from the displacement of the arrival position of that ion. Then the flight speed of the ion is obtained and its number of turns is roughly deduced to arrive at its mass-to-charge ratio.

Growing community of inventors

Uji, Japan

Osamu Furuhashi