Hitachi, Ltd.

Katsuhiro Nakagawa

Yoshiaki Kato

Kiyomi Yoshinari

Yoichi Ose

Shinji Nagai

Depending on the RF driving voltage amplitude value and the frequency of each frequency component of wideband auxiliary AC voltages, the wideband auxiliary AC voltage comprising plural different frequency components is optimized so that undesired ions having mass-to-charge ratios within the required range will be resonantly ejected from the ion trap electrodes.

Apparatus for mass spectrometry on an ion-trap method

An numerical analysis time which is assigned to mass select one ion species having a specific mass-to-charge ratio mass selected is divided into the first part time and the second part time, and a dipole auxiliary electric field capable of spatially reducing a spread is superimposed in the first part time of the numerical analysis time and a quadrupole auxiliary voltage capable of rapidly emitting ions when position coordinates are large is superimposed in the second part of the time. Therefore, the initial spatial spread is reduced in the first part time and the trajectories of ions is rapidly amplified in the second part time, and the ions are emitted. Thus, the entire mass sweep time can be reduced and a high-resolution numerical analysis can be accelerated.

Ion-trap mass analyzing apparatus and ion trap mass analyzing method

A sample separated through a pre-processor part having a gas chromatography (GC) or a liquid chromatography (LC) and a moving bed eliminating part is ionized by an ion source and mass-analyzed by a mass-analyzing part. The mass-analyzed ions are deflected and focused by a deflecting portion and a focusing portion in a deflecting and focusing part, and is detected by an ion detecting part. The result of detection is processed by a data processing part.

Mass spectrometer

In a mass analyzer, an acceleration voltage is applied to an ionization chamber in which a voltage to be applied to repeller electrodes to repel ions is generated with reference to the acceleration voltage and a repeller voltage source is linked with a controller by use of a photocoupler or the like such that the repeller voltage is adjusted with the repeller voltage source electrically insulated from the controller. The repeller voltage can be easily and automatically adjusted by use of a low-voltage control signal so as to obtain a sensitivity developing the maximum value of the quantity of detected ions and hence a qualitative or quantitative analysis of a sample can be achieved with a high sensitivity. The controller processes digital signals and appropriate parameters are stored in a memory. Each parameter is changed with the center of change set to an appropriate parameter previously used and consequently the automatic control is simplified.

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Hitachiohta, Japan

Katsuhiro Nakagawa