Abstract: In a scan measurement in which a mass scan is repeated across a predetermined mass range, when a voltage is returned from a termination voltage of one scan to an initiation voltage for the next scan, an undershoot or other drawbacks occur to destabilize the voltage value. Therefore, an appropriate waiting time is required. Conventionally, this waiting time has been set to be constant regardless of the analysis conditions. On the other hand, in the quadrupole mass spectrometer according to the present invention, the mass difference ?M between the scan termination mass and the scan initiation mass is computed based on the specified mass range, and a different settling time is set in accordance with this mass difference. When the mass difference ?M is small and hence requires only a short voltage stabilization time, a relatively short settling time is set. This shortens the cycle period of the mass scan, which increases the temporal resolution.

Abstract: In a scan measurement in which a mass scan is repeated across a predetermined mass range, when a voltage is returned from a termination voltage of one scan to an initiation voltage for the next scan, an undershoot or other drawbacks occur to destabilize the voltage value. Therefore, an appropriate waiting time is required. Conventionally, this waiting time has been set to be constant regardless of the analysis conditions. On the other hand, in the quadrupole mass spectrometer according to the present invention, the mass difference ?M between the scan termination mass and the scan initiation mass is computed based on the specified mass range, and a different settling time is set in accordance with this mass difference. When the mass difference ?M is small and hence requires only a short voltage stabilization time, a relatively short settling time is set. This shortens the cycle period of the mass scan, which increases the temporal resolution.

Abstract: In conventional mass spectrometers, if ions are converged by a radio-frequency electric field under the condition of relatively high gas pressure, the ions are decelerated and are delayed, or stagnated in an extreme case, to cause a decrease in the detection sensitivity or an appearance of a ghost peak. By contrast, in the mass spectrometer according to the present invention, lens electrodes 40 comprises four plate-shaped electrodes 41a through 41d, which are radially arranged around the ion optical axis C at intervals of 90 degrees from each other; the four electrodes placed in the plane being approximately perpendicular to the ion optical axis C form a group, and a plurality of the groups are arranged along the ion optical axis C direction at approximately even intervals. The radio-frequency voltages each applied to each of any pair of electrodes adjacent along the direction of the ion optical axis C have a given amount of phase shift.

Abstract: If a scanning rate of a mass scanning is set to be high, the amount of change in an applied voltage between a time of an incidence of a certain ion into a quadrupole mass filter and a time of an emission of the ion therefrom increases. This leads to a change in the condition of a passage of ions, causing the amount of ions to decrease and thereby deteriorating detection sensitivity. In order to avoid this problem, according to the present invention, the values of direct current voltage U and an amplitude V of radio-frequency voltage, both voltages being applied to rod electrodes during a mass scanning, are respectively determined so that a voltage ratio U/V of the voltage U to the amplitude V becomes smaller as the scanning rate becomes higher.

Abstract: The present invention aims at suppressing noises when a mass analysis is performed by introducing a sample solution into an atmospheric pressure ion source by a pressurized liquid feeding method. As a dilution solvent of the sample solution contained in a sample container, a mixed liquid is used in which the mixture ratio of an organic solvent such as methanol is decreased to 20% and the ratio of water is 80%. Since nitrogen, which is a gas for the pressurization, is soluble in an organic solvent, decreasing the ratio of the organic solvent lowers the saturated dissolution amount and suppresses unstable emergence of the gas in the process of the mass analysis. Consequently, even after the elapse of a considerable length of time from the start of liquid feeding, spike-like noises do not appear in the ion intensity, which stabilizes the ion intensity.

Abstract: A sample solution introduction device for a mass spectroscope includes a container device including a container having an opening at a top portion thereof and a blocking plug for blocking the opening, a gas supply device for supplying predetermined gas into the container, a first inner container provided inside the container, and an inner container supporting device for suspending and supporting the first inner container to the blocking plug. A liquid transmission pipe passes through the blocking plug. The liquid transmission pipe has one end to be soaked in a liquid sample inside the first inner container, and the other end located outside the container. The liquid sample is pushed by gas pressure supplied by the gas supply device.

Abstract: A table (21) for relating an appropriate DC bias voltage to each of a plurality of selectable scan speeds is stored beforehand in an auto-tuning data memory section (20). In an auto-tuning operation, a controller (10) determines the DC bias voltage corresponding to each scan speed by referring to the table (21) and fixes the output of an ion-drawing voltage generator (13) at that voltage. Subsequently, while changing the voltages applied to relevant sections such as an ion optical system (2), the controller (10) finds voltage conditions under which the detection signal is maximized. The conditions thus found are stored in an auto-tuning result data (22). In an analysis of a target sample, a DC bias voltage corresponding to a scan speed specified by an operator is obtained from the DC bias voltage table (21), and the optimal conditions for this voltage are obtained from the auto-tuning result data (22). Based on these items of information, conditions for the scan measurement are determined.

Abstract: The length of the collision cell (20) in the direction along the ion optical axis (C) is set to be within the range between 40 and 80 mm, and typically 51 mm, which is remarkably shorter than before. The CID gas is supplied so that it flows in the direction opposite to the ion's traveling direction. Since the energy that an ion receives in colliding with a CID gas increases, it is possible to practically and sufficiently ensure the CID efficiency even though the collision cell (20) is short. In addition, since the passage distance for an ion is short, the passage time is shortened. Accordingly, it is possible to avoid the degradation in the detection sensitivity and the generation of a ghost peak due to the delay of the ion.

Abstract: An object of the present invention is to provide a mass spectrometer having an optical ion transport system where the efficiency for generating and converting fragment ions can be increased, and which can transport the generated fragment ions efficiently to the rear stage, and in order to achieve this object, the mass spectrometer for ionizing a sample in an ionization chamber 10 and drawing the ionized sample into a mass spectrometric chamber 18 is provided with an ion transport optical system having electrodes 17, 200-1 and 200-2 provided so as to surround an optical ion axis, and is characterized in that the above described electrodes 17, 200-1 and 200-2 have an inclined surface which is inclined so as to spread in the direction in which ions progress along the above described optical ion axis.

Abstract: The inside of the collision cell 20 placed in the analysis chamber 10 which is vacuum-evacuated is partitioned into an anterior chamber 23 and a posterior chamber 24 by the partition wall 21 with a communicating aperture 22. The former is used as a dissociation area A1 and the latter as a convergence area A2. Electrodes 27 and 28 for forming a radio-frequency electric field are placed in the chambers 23 and 24, respectively. When a CID gas is supplied into the anterior chamber 23, the CID gas is dispersed inside the anterior chamber 23 and flows into the analysis chamber 10 via the posterior chamber 24. Consequently, the gas pressure in the posterior chamber becomes higher than the gas pressure in the analysis chamber 10, and the gas pressure in the anterior chamber 23 becomes higher than the gas pressure in the posterior chamber 24.

Abstract: The direct current bias voltage to be applied to the pre-filter 13 provided in the previous stage of the quadrupole mass filter 14 for selecting an ion according to the mass-to-charge ratio is changed in accordance with the mass-to-charge ratio of the target ion to be allowed to pass through, in order that the time period required for an ion to pass through the pre-filter 13 is uniformed regardless of the mass-to-charge ratio, and simultaneously the phase of the oscillation of ions at the entrance of the quadrupole mass filter 14 is also uniformed. In the range where the mass-to-charge ratio is larger than some degree, the ion's oscillation itself is small, and in addition, the ion's passage efficiency deteriorates rather than enhances, due to the potential barrier created by the voltage difference from the direct current bias voltage applied to the quadrupole mass filter 14.

Abstract: Disclosed is a mass spectrometer, which includes an ion optical system for converging ions and transporting the ions to a subsequent stage. Instead of a conventional rod-shaped electrode, the ion optical system includes an electrode formed of a thin metal plate member. Specifically, each of four electrodes 41a to 41d formed of the metal plate members has an edge surface facing an ion optical axis C and extends along the ion optical axis C. Further, the electrodes 41a to 41d are disposed around the ion optical axis C in a radial pattern while keeping an angle of 90° between the adjacent electrodes. The present invention can provide the ion optical system at a lower cost.

Abstract: In conventional mass spectrometers, if ions are converged by a radio-frequency electric field under the condition of relatively high gas pressure, the ions are decelerated and are delayed, or stagnated in an extreme case, to cause a decrease in the detection sensitivity or an appearance of a ghost peak. By contrast, in the mass spectrometer according to the present invention, lens electrodes 40 comprises four plate-shaped electrodes 41a through 41d, which are radially arranged around the ion optical axis C at intervals of 90 degrees from each other; the four electrodes placed in the plane being approximately perpendicular to the ion optical axis C form a group, and a plurality of the groups are arranged along the ion optical axis C direction at approximately even intervals. The radio-frequency voltages each applied to each of any pair of electrodes adjacent along the direction of the ion optical axis C have a given amount of phase shift.

Abstract: A sample solution introduction device for a mass spectroscope includes a container device including a container having an opening at a top portion thereof and a blocking plug for blocking the opening, a gas supply device for supplying predetermined gas into the container, a first inner container provided inside the container, and an inner container supporting device for suspending and supporting the first inner container to the blocking plug. A liquid transmission pipe passes through the blocking plug. The liquid transmission pipe has one end to be soaked in a liquid sample inside the first inner container, and the other end located outside the container. The liquid sample is pushed by gas pressure supplied by the gas supply device.

Abstract: Disclosed is a mass spectrometer, which includes an ion optical system for converging ions and transporting the ions to a subsequent stage. Instead of a conventional rod-shaped electrode, the ion optical system includes an electrode formed of a thin metal plate member. Specifically, each of four electrodes 41a to 41d formed of the metal plate members has an edge surface facing an ion optical axis C and extends along the ion optical axis C. Further, the electrodes 41a to 41d are disposed around the ion optical axis C in a radial pattern while keeping an angle of 90° between the adjacent electrodes. The present invention can provide the ion optical system at a lower cost.

Abstract: In a liquid chromatograph mass spectrometer, a liquid sample supplied from an LC portion is nebulized in an ionization chamber, and the produced nebulized sample is ionized by applying a high voltage thereto and is introduced into a mass spectrometry chamber. A supply flow path of a nitrogen gas and an oxygen gas is connected to the ionization chamber, and a control mechanism for controlling a composition ratio of the nitrogen gas and the oxygen gas in the ionization chamber is provided to thereby ionize at an optimum gas composition ratio.

Abstract: A mass spectrograph with an ionization chamber for having a sample liquid sprayed into and generating ions to be analyzed in a mass analyzing chamber for analyzing the generated ions has a peep-hole with a transparent pane provided on a wall of the ionization chamber. In order to prevent the pane from becoming cloudy and make it possible to clearly see the interior of the chamber, a tube is provided inside the chamber for blowing a dry gas onto the inner surface of the pane. The pane may be formed in the shaped of an image-enlarging lens and its inner surface may be coated with a thin film of polytetrafluoroethylene. An LED may be positioned inside the chamber such that the interior of the chamber can be seen clearly even if mass spectrograph is placed in a relatively dark room.

Abstract: A liquid chromatograph mass spectrometer is provided with an interface portion between a liquid chromatograph portion and a mass spectrometry portion. In the interface portion, an ionizing device is provided to ionize a liquid sample sent from the liquid chromatograph portion. Also, a desolvating device is provided to remove a solvent from the produced ions or charged droplets by the ionizing device. Then, the sample is introduced into the mass spectrometry portion. The interface portion has a plurality of ionizing devices for ionizing the liquid sample by different methods.

Abstract: A mass spectrometer is structured such that a lens unit is firmly kept at a fixed position inside a main body by providing springs and hooking their top ends by hooks while their bottom ends are affixed to the main body such that the elastic force of the deformed springs presses the lens unit against one of inner walls of the main body.

Abstract: A mass spectrograph with an ionization chamber for having a sample liquid sprayed into and generating ions to be analyzed in a mass analyzing chamber for analyzing the generated ions has a peep-hole with a transparent pane provided on a wall of the ionization chamber. In order to prevent the pane from becoming cloudy and make it possible to clearly see the interior of the chamber, a tube is provided inside the chamber for blowing a dry gas onto the inner surface of the pane. The pane may be formed in the shaped of an image-enlarging lens and its inner surface may be coated with a thin film of polytetrafluoroethylene. An LED may be positioned inside the chamber such that the interior of the chamber can be seen clearly even if mass spectrograph is placed in a relatively dark room.