Shimadzu Corporation

Osaka University

Masaru Nishiguchi

Shinichi Yamaguchi

Daisuke Okumura

Yoshihiro Ueno

Akiko Imazu

Shinji Miyauchi

Shigeki Kajihara

Manabu Shimomura

Osamu Furuhashi

Hiroto Itoi

Kiyoshi Ogawa

Michisato Toyoda

Motohide Yasuno

Ryo Fujita

Takeshi Uchida

Ryo Kageyama

Hiroki Sakae

A method for driving a linear ion trap having rod electrodes arranged so as to surround a central axis includes: an ion-introducing step for introducing ions into an ion-capturing space surrounded by the rod electrodes, and for capturing the ions by a multipole RF electric field created within the ion-capturing space; and an ion-ejecting step for creating both a DC electric field for ion extraction extending from an external area outside the ion-capturing space into the ion-capturing space through a space between two predetermined rod electrodes neighboring each other around the central axis among the plurality of rod electrodes and the multipole RF electric field, and for sequentially ejecting ions according to their m/z from the ion-capturing space toward the external area through the space between the two predetermined rod electrodes by changing at least one of the multipole RF electric field and the DC electric field.

Method for driving linear ion trap and mass spectrometer

The present mass spectrometer has one or more intermediate vacuum chambers between an ion source to generate ions derived from a sample component in an atmospheric pressure atmosphere and a vacuum chamber where a mass separator is arranged, including an ion transport unit to have an ion outlet in a first intermediate vacuum chamber at a subsequent stage of the ion source and send ions to the first chamber, an exhaust opening portion to evacuate the first chamber, which is provided in front of ion flow discharged from the ion outlet into the first chamber, an ion delivery opening portion to send ions to a next stage, which is provided on a line intersecting a straight line connecting the ion outlet and the exhaust opening portion, and an ion guide to guide ions to the ion delivery opening portion by an action of a radio-frequency electric field.

Mass spectrometer

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

An ion analyzer includes an ion optical element having four rod electrodes around an optical axis, for transferring ions from their surrounding space to the subsequent stage while converging the ions. To create an RF electric field within this space, a voltage supplier applies RF voltages of opposite polarities to two pairs of electrodes facing each other across the axis. The cross-sectional shape of each electrode in a plane orthogonal to the axis has a first side having width w facing the axis and is tangent to a circle of radius raround the axis, and two adjacent sides connected to the ends of the first side at an angle determined so that an RF field created by the adjacent sides exerts no influence within the space. The ratio w/ris determined so that the amount of dodecapole field component becomes a predetermined value or does not exceed it.

A mass spectrometry device includes a vacuum container in which an ionizer, a mass separator and a detector are arranged, and includes an opening-closing portion that is provided at the vacuum container and switches between a locked state of being locked in a close state and an unlocked state by a difference in pressure between inside and outside of the vacuum container, and a cooling gas introducer that introduces a cooling gas for cooling the ionizer into the vacuum container such that the opening-closing portion is kept in the locked state.

Mass spectrometry device and mass spectrometry method

An ion guide () provided in a first intermediate vacuum chamber includes six rod electrodes (to) and a voltage generation unit. The six rod electrodes (to) are in a hexapole arrangement on the ion incident side, and the two rod electrodes (and) are tilted with respect to the Z-axis in a manner approaching a central axis () as they progress in the ion transport direction, so that the four rod electrodes (, and) are in a quadrupole arrangement. The voltage generation unit applies radio-frequency voltages ±V cos ωt whose phases are inverted to each other between adjacent rod electrodes of the six rod electrodes (to) around the central axis (), applies a DC voltage Uto the four electrodes (, and) by which ions pass through them in an excellent manner, and applies a DC voltage Udifferent from Uto the other two rod electrodes (and).

An ionizerincluding an ionization chamber, a sample gas introduction portprovided in the ionization chamberfor introducing sample gas, an electron beam emitting sectionwhich emits an electron beam toward the ionization chamber, electron beam passage openingsandwhich are formed on a path of the electron beam emitted from the electron beam emitting sectionon a wall of the ionization chamberand has a length in a direction of the path longer than a width of a cross section orthogonal to the direction, and an ion outletprovided in the ionization chamberfor emitting an ion of the sample gas generated by irradiation with the electron beam, and a mass spectrometerincluding the ionizer

Ionizer and mass spectrometer

A quadrupole mass spectrometer includes: a quadrupole mass filter including a pre-rod; an ionization chamber; and an ion optical system that guides ions generated in the ionization chamber to the pre-rod of the quadrupole mass filter, wherein: a potential of an exit side electrode of the ion optical system is lower than a potential of the ionization chamber and a potential of the pre-rod of the quadrupole mass filter; and there is no structure that has a higher potential than the exit side electrode and decelerates the ions between the exit side electrode and the pre-rod.

Quadrupole mass spectrometer

A quadrupole mass spectrometer includes: a quadrupole mass filter with four rod electrodes arranged so as to surround a central axis; and a magnet that forms a magnetic field in at least a part of an inside of the quadrupole mass filter in a direction intersecting the central axis.

An ion detector () includes a shield electrode () between an aperture plate () and a conversion dynode (). The shield electrode () has a rectilinearly-moving particle block wall () positioned on an extension line (C') extending from the central axis (C) of a quadrupole mass filter (), and an ion attracting electric field adjustment wall () inclined by a predetermined angle &#x3b8; (acute angle) with respect to the extension line (C&#x2032;). In the ion attracting electric field adjustment wall () is provided an ion passing aperture (). The rectilinearly-moving particles, such as neutral particles, which are ejected from the quadrupole mass filter (), are blocked by the rectilinearly-moving particle block wall (), thereby reducing noises caused by the rectilinearly-moving particles. Meanwhile, the potential of the ion attracting electric field adjustment wall () corresponds to equipotential surfaces in a strong electric field formed by the conversion dynode (), and thus the condition of the strong electric field is not remarkably changed from the state where no shield electrode () is provided. Therefore, the effect of drawing ions is exhibited, thereby maintaining the high ion-detection efficiency.

Ion detection device and mass spectrometer

A focusing electrode () of a flat plate shape is arranged so that an inlet end () of a heated capillary () for introducing ions into a vacuum chamber as a subsequent stage is inserted into an opening portion () of the focusing electrode (). A reflecting electrode () of a flat plate shape is arranged at a position opposing the focusing electrode () across a spray flow ejected from an ionization probe (). An auxiliary electrode () is grounded and arranged between the ionization probe () and each of the reflecting electrode () and the focusing electrode (). The heated capillary () is grounded, and during a measurement of positive ions, a voltage V1 and a voltage V2, both satisfying a relationship of V1&#x3e;V2&#x3e;0, are respectively applied to the reflecting electrode () and the focusing electrode (). A reflecting electric field for reflecting and deflecting ions generated from sample components and carried by the spray flow is created within a space between the reflecting electrode () and the focusing electrode (), and a focusing electric field for focusing ions to the inlet end () is created in an area near the inlet end (). The ions generated from sample components are separated from a gas stream and efficiently collected into the inlet end (), to be drawn into the heated capillary () and sent to a mass spectrometry section.

Mass spectrometry device and ion detection device

A cylindrically-shaped auxiliary electrode and a cylindrically-shaped reflecting electrode are located anterior to a spray flow ejected from an ESI ionization probe. An inlet end of a heated capillary extends into the space between the two electrodes. The auxiliary electrode and heated capillary are grounded, while the reflecting electrode is supplied with a direct-current voltage having the same polarity as measurement target ions. As a result, a reflecting electric field which reflects ions originating from sample components and charged droplets, being carried by the spray flow, is created within the space between the two electrodes. A focusing electric field for focusing ions onto the inlet end is also created in an area near the inlet end. The ions originating from sample components are thereby separated from the gas flow and gathered around the inlet end, to be drawn into the heated capillary and sent into a vacuum chamber.

Mass spectrometer and ion mobility spectrometer

A mass spectrometer includes a collision cell () converging electrode (), accelerating electrode () and front-side ion lens system () which is an electrostatic lens, which are all located within a medium-vacuum region, and a partition wall () for separating the medium-vacuum region from a high-vacuum region and an ion transport optical system () located within the high-vacuum region. Ions which have been extracted and accelerated by an accelerating electric field created between an exit electrode () and the accelerating electrode () are focused into a micro-sized ion-passage opening () by the converging electrode (). The accelerating electrode () blocks a stream of gas, thereby decreasing the chance of contact of ions with gas particles behind the electrode. Additionally, the accelerating electric field imparts a considerable amount of kinetic energy to the ions, thereby preventing the ions from being dispersed even when they come in contact with the gas particles.

A drift voltage generator applies voltages to a plurality of annular electrodes, respectively, so that a potential distribution &#x3c6; on an ion beam axis of an accelerating electric field created within a drift region satisfies &#x2202;&#x3c6;/&#x2202;Z&#x3e;0. Trailing ions undergo a higher rate of acceleration than preceding ions, so that a compressing force acts on an ion packet in the direction of the ion beam axis. Consequently, the ion packet is constantly confined to a smaller space in the direction of the ion beam axis, and ions having the same ion mobility form a narrower peak in a spectrum with the horizontal axis representing the drift time, so that the resolving power improves. A control unit switches the applied voltages so that a uniform accelerating electric field is created.

Ion mobility analyzer and mass spectrometer

An off-axis ion transport optical system () including a front-stage quadrupole ion guide (), a rear-stage quadrupole ion guide (), and an ion deflector () is disposed inside an intermediate vacuum chamber () in a stage next to an ionization chamber () maintained at an atmospheric pressure. Both of the quadrupole ion guides (and) have the same configuration as that of a conventional ion guide that transports ions while trapping the ions using a radio-frequency electric field. The ion deflector () includes a pair of parallel flat electrodes (and) and deflects ions using a direct-current electric field. By causing the deflected ions to reach the ion receiving range of the rear-stage quadrupole ion guide (), it is possible to efficiency introduce ions while deflecting the ions. Meanwhile, the ions and neutral particles are separated from each other in the ion deflector (). This provides an off-axis structure ion transport optical system that achieves a high ion transmission efficiency with a simple structure.

Growing community of inventors

Kyoto, Japan

Masaru Nishiguchi