Shimadzu Corporation

Akiko Imazu

Masaru Nishiguchi

Motohide Yasuno

Osamu Furuhashi

Hideaki Izumi

Yoshinori Arita

Hiroki Sakae

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 mobility analyzing apparatus includes: a drift tube having an internal space extending in a first direction; an ion chamber having an internal space extending in the first direction and connected to the drift tube; an ion gate installed at a boundary between the drift tube and the ion chamber and kept at a ground potential; an ion source supplying ions into the ion chamber; an ion detecting electrode arranged in the drift tube on a side opposite to the ion gate; a first voltage source supplying a first high voltage to the ion chamber; a second voltage source supplying a second high voltage, having an opposite polarity to that of the first high voltage, to the ion detecting electrode; and a signal transfer unit that detects a signal from the ion detecting electrode and transmits the signal to a data processing device operating with the ground potential.

Ion mobility analyzing apparatus

A first shutter gate is disposed at an entrance of a drift region, and a second shutter gate is disposed on the downstream side in an ion-drifting direction. In a high-resolution measurement mode, a controller () controls voltage generators to open the second shutter gate to collect ions into a pulsed form at the first shutter gate. In this mode, the controller controls the voltage generators to open the first shutter gate to collect ions into a pulsed form at the second shutter gate. In a zoom-in measurement mode where ions within a specified range of ion mobility are measured with high resolving power, the controller controls the voltage generators to open the first shutter gate for a short period of time, and then to open the second shutter gate for a short period of time after a lapse of a predetermined time period.

Ion mobility spectrometer

A gate electrode (A) used as a shutter gate includes a pair of conductive fixture members () made of metal and identical in size attached to the inside of a rectangular opening () of a ceramic base (), along with insulating fixture members () made of ceramic attached to the inner sides of the conductive fixture members. Two comb electrodes () as one pair have connecting portions () adhered to the conductive fixture members () as well as thin-wire electrodes whose distal ends are adhered to the insulating fixture members (). By setting length L of the opening () and width D of the conductive fixture members () to appropriate values according to the coefficient of thermal expansion of each of those members, the elongation of the electrodes which accompanies an increase in temperature can be balanced by the increase in the distance between the adhered positions of the electrodes to prevent the electrodes from being excessively taut or slack. Therefore, the drift region can be heated to a higher temperature than conventional levels to perform a high-accuracy, high-resolution analysis free from the influence of residual water vapor or similar particles.

Gate electrode and ion mobility 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.

Ion transport apparatus and mass spectrometer using the same

Within an intermediate vacuum chamber next to an ionization chamber maintained at atmospheric pressure, an electrode group of a radio-frequency carpet composed of a plurality of concentrically arranged ring electrodes is placed before a skimmer, with its central axis coinciding with that of an ion-passing hole. Each ring electrode has a circular radial sectional shape. Radio-frequency voltages with mutually inverted phases are applied to the ring electrodes neighboring each other in the radial direction. Additionally, a different level of direct-current voltage is applied to each ring electrode to create a potential which is sloped downward from the outer ring electrode to the inner ring electrode. The circular cross section of the electrode produces a steep pseudo-potential near the electrode and thereby increases the repulsive force which acts on the ions to repel them from the electrode.

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Kyoto, Japan

Akiko Imazu