Mass spectrometer

Abstract

To improve the performance of a mass spectrometer.SOLUTION: An ion trap type mass spectrometer that ionizes a sample adhering to a test object and separates ions on the basis of the mass and charge, comprises: a heating unit 1 which heats and vaporizes a sample; a sample introduction tube 10 which introduces the sample vaporized by the heating unit 1 to an ion source 15; the ion source 15 which applies a charge to the sample; a container 210 whose inside is in the vacuum state; a first pore 51 which introduces the sample ionized by the ion source 15 to the container 210; an ion trap unit 300 which is provided in the container 210; and a second pore 71, an intermediate lens 90 and an adjustment lens 110 which are sequentially provided between the first pore 51 and the ion trap unit 300 and transports the ions being the sample introduced to the container 210 to the ion trap unit 300. In the adjustment lens 110, the amount of ions passing through the adjustment lens 110 is controlled by a control unit connected to the mass spectrometer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a mass spectrometer. [Background technology]

[0002] Mass spectrometers are known as devices that convert substances into atomic or molecular ions using various ionization methods, separate the multiple types of ions based on the mass and charge of the ions, and measure the number of ions to identify or quantify the substances. The measured substance has a characteristic molecular weight based on the type and number of atoms that compose it. Mass spectrometers directly ionize and measure the atoms and molecules, making it possible to perform ultra-sensitive measurements, substance identification, and structure analysis. Due to these characteristics, mass spectrometers are used in the environmental analysis field for testing drinking water, screening or quantification of pesticides, air pollution monitoring, and trace element analysis of heavy metal elution. Mass spectrometers are also used in the medical analysis field for research on absorption, distribution, metabolism, and excretion in the body during drug discovery, or screening of pharmacokinetics or metabolites. Currently, mass spectrometers are widely used to measure inorganic and organic substances.

[0003] Patent Document 1 (JP Patent Publication No. 2001-249114) describes the separation of a sample (MS1) and the acquisition of standard mass spectrum data by tandem mass analysis (MS2), and the measurement of the sample introduced from a chromatograph using an ion trap mass spectrometer.

[0004] Patent Document 2 (JP Patent Publication No. 2005-91344) describes performing multiple measurements on the same sample in the structural analysis of complex components (proteins, peptides, etc.). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-249114 A [Patent Document 2] JP 2005-91344 A Summary of the Invention [Problem to be solved by the invention]

[0006] Among the various types of mass spectrometers, the ion trap type is said to be superior in identification (qualitative analysis). One application of mass spectrometers is the detection of chemical substances attached to the test substance. In this case, the surface of the test substance is wiped, ionized, and mass separation and tandem mass analysis are performed to identify the target chemical substance. If the test subject is unspecified, the amount of sample wiped off is naturally unspecified. When using an ion trap type mass spectrometer, the amount of ions that can be trapped in the ion trap at one time is limited, so if the concentration of the observed chemical substance is high, the linearity of the concentration and signal intensity is lost, making it difficult to determine the concentration. In addition, it is difficult to separate the components of the wiped sample when introducing it into the mass spectrometer, and the mass spectrum obtained by analysis contains not only the mass spectrum of the target chemical substance, but also chemical substances other than the target substance that were present in the test substance, substances originating from the environment in which the device is placed, and mass spectra of the cloth or paper components used for wiping. Furthermore, when multiple ions are ionized simultaneously, the mass spectrum signal intensity from the target chemical substance may be lower than when it is ionized alone. Therefore, it is difficult to compare it with a previously obtained mass spectrum.

[0007] The technology described in Patent Document 2 stores data on precursor ions and product ions at fixed times, and in the next measurement, selects a precursor ion different from the precursor ion observed in the previous measurement and performs MS2 analysis. In this case, however, multiple measurements are required to identify multiple types of chemical substances. In detecting chemical substances attached to a test target substance, there are cases where the same sample can only be measured once, and in such cases, the technology cannot identify multiple chemical substances.

[0008] The object of the present invention is to provide a mass spectrometer that uses an ion trap type mass spectrometer to detect chemical substances adhering to the surface of a test object, which improves the linear relationship between the amount of ions and the detection signal caused by the finite spatial capacity of the ion trap, by improving the linear relationship range and thus the quantitative accuracy, in a case where the test object is unspecified and the amount of sample introduced into the mass spectrometer is unspecified, and thus the linear relationship range is expanded, and the quantitative accuracy is stabilized. Another object of the present invention is to detect multiple chemical substances with different target concentrations in a single sampling.

[0009] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0010] A brief outline of a representative embodiment of the present invention will be described below.

[0011] A mass spectrometer according to one embodiment is an ion trap type mass spectrometer that ionizes a sample attached to an object to be inspected and separates the ions based on their mass and charge, and includes a heating unit that heats and vaporizes the sample, a first gas supply pipe that introduces the sample vaporized by the heating unit into an ion source, the ion source that applies an electric charge to the sample, a container whose inside is in a vacuum state, a first aperture that introduces the sample ionized by the ion source into the container, an ion trap unit provided in the container, a second aperture that is provided in order between the first aperture and the ion trap unit and transports the ions of the sample introduced into the container to the ion trap unit, an intermediate lens, and an adjustment lens. Here, the first aperture is the boundary between atmospheric pressure and vacuum pressure, and the amount of ions passing through the adjustment lens is controlled by a control unit connected to the mass spectrometer. Effect of the Invention

[0012] The effects obtained by the representative inventions among those disclosed in this application will be briefly described as follows.

[0013] According to the present invention, the performance of a mass spectrometer can be improved. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing a mass spectrometer according to a first embodiment. [Diagram 2] 1 is a table showing the necessary detection amount and control voltage for each sample to be detected. [Diagram 3] 1 is a graph showing the relationship between control voltage and signal strength. [Figure 4] FIG. 11 is a schematic diagram showing a mass spectrometer according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments, the same reference numerals are used for the members having the same functions, and the repeated explanations are omitted. In addition, in the following embodiments, the explanations of the same or similar parts are not repeated in principle, except when particularly necessary. In addition, in the drawings for explaining the embodiments, hatching may be used even in plan views or perspective views, etc., in order to make the configuration easier to understand. Furthermore, in the drawings for explaining the embodiments, hatching may be omitted in cross-sectional views in order to make the configuration easier to understand.

[0016] <Details of areas for improvement> Below, we will explain room for technical improvement of mass spectrometers.

[0017] There are several methods for separating ions based on their mass and charge in mass spectrometers. Representative methods include double focusing, quadrupole, ion trap, time-of-flight, and Fourier transform. Each method has its own characteristics, such as the measurement mass range, resolution, and whether or not tandem mass analysis can be performed. Among these, the ion trap type, as its name suggests, traps ions in a three-dimensional space. Ion trapping is achieved by forming a radio-frequency electric field between two electrodes. By changing the radio-frequency voltage applied to the electrodes, ions are ejected from the ion trap electrodes to the detector and mass separation is performed. It is possible to trap only specific ions in the ion trap, and tandem mass analysis is possible due to this characteristic. Ions trapped in the ion trap in tandem mass analysis are called precursor ions, and ions generated from precursor ions are called product ions. By analyzing the mass spectra of these precursor ions and product ions, it is possible to analyze the structure of the measured sample. It is also possible to trap multiple types of ions simultaneously in the ion trap, and it is possible to obtain a mass spectrum by trapping and ejecting them in one go. Ion trap types are excellent for identification because they are capable of tandem mass analysis and can measure mass spectra with high efficiency.

[0018] In addition, mass spectrometers have a linear relationship between the amount of ions introduced and the observed signal intensity. Therefore, it is possible to determine the concentration of the measured sample from the number of ions observed (quantitative analysis). On the other hand, in the case of ion trap type, the space in which ions are trapped is a finite three-dimensional space, so there is a limit to the number of ions that can be trapped at one time, and the quantitative range may be limited.

[0019] Here, the mass spectrometer can be used to detect chemical substances attached to the test substance. The surface of the test substance is wiped, the wiped sample is directly heated and ionized, and mass separation and tandem mass analysis are performed to identify the target chemical substance. If the test subject is unspecified, the amount of sample wiped off is naturally unspecified. Furthermore, in detecting the target chemical substance, the concentration may be required at the same time as the identification. However, when using an ion trap mass spectrometer, the amount of ions that can be trapped in the ion trap at one time is limited as described above. For this reason, when the concentration of the observed chemical substance is high, the linearity between the concentration and the signal intensity is lost, making it difficult to determine the concentration. In other words, there is room for the first improvement, which is to maintain the linearity between the amount of ions and the concentration regardless of the concentration of the sample.

[0020] In the technology described in Patent Document 1, components (chemical substances) of a measurement sample are separated by a chromatograph device and introduced into a mass spectrometer. At the time of ionization, the measurement sample is composed almost entirely of separated components, making it possible to compare the mass spectrum with that obtained from a standard sample whose concentration has been specified in advance. For the same reason, it becomes possible to select precursor ions during sample separation when performing tandem mass spectrometry, and the mass spectrum of product ions generated in tandem mass spectrometry can also be compared with the mass spectrum obtained from a standard sample obtained in advance. For this reason, Patent Document 1 improves the precision of precursor ion selectivity by comparing the mass spectrum obtained from the standard sample with the mass spectrum obtained from the actual sample, and identifies components from the product ions.

[0021] On the other hand, when detecting chemical substances attached to the test substance, it is not clear what components are contained in the test sample, and due to the required characteristics of the device, it is necessary to measure for several tens of seconds for each sample. Therefore, it is difficult to separate the components when introducing them into the mass spectrometer, and after wiping, the test sample is ionized by direct heating and introduced into the mass spectrometer in a state where it is almost completely unseparated. Therefore, the mass spectrum obtained by sample separation (MS1) contains, in addition to the mass spectrum of the target chemical substance, chemical substances other than the target substance that were present in the test substance, substances originating from the environment in which the device is placed, and mass spectra of the cloth or paper components used for wiping. Furthermore, when multiple ions are ionized simultaneously, the mass spectrum signal intensity from the target chemical substance may be lower than when only the target chemical substance is ionized. Therefore, there is a second room for improvement in that it is difficult to identify the target chemical substance by comparing it with a mass spectrum obtained in advance.

[0022] The technology described in Patent Document 2 stores data on precursor ions and product ions at fixed times, and in the next measurement, selects a precursor ion different from the precursor ion observed in the previous measurement and performs tandem mass spectrometry (MS2 analysis). In this case, however, multiple measurements are required to identify multiple types of chemical substances. In detecting chemical substances attached to a test target substance, there are cases where the same sample can only be measured once, and in such cases, the technology cannot identify multiple chemical substances. In other words, there is room for a third improvement in that multiple types of chemical substances cannot be identified when the same sample can only be measured once.

[0023] Therefore, in the following embodiment, a device is provided to solve the above-mentioned first, second, and third room for improvement. The technical idea of ​​the present embodiment that has the device will be described below.

[0024] (Embodiment 1) <Mass spectrometer configuration> 1 is a schematic diagram of a mass spectrometer according to the present invention. Mass spectrometer 540 is connected to a control unit 500, which is, for example, a control personal computer, via a communication line, and mass spectrometer 540 operates under the control of control unit 500. Control unit 500 includes a memory unit 510.

[0025] The mass spectrometer 540 includes a heating unit 1, an ion source 15, a first pore plate 50, a vessel 210, a signal detection board 230, and an apparatus control board 250. The first pore plate 50 has a first pore 51 penetrating the plate. The opening of the vessel 210 is closed by the first pore plate 50. A vacuum pump (not shown) is connected to the vessel 210, and the inside of the vessel 210 is vacuum-filled with, for example, 10 -4 It becomes a vacuum state of Pa.

[0026] A high voltage application unit (needle electrode) 20 for applying a high voltage thereto and a sample gas delivery pipe (gas delivery piping) 10 for delivering a gas of a measurement sample heated by the heating unit 1 are inserted into the ion source 15. The first pore 51 of the first pore plate 50 is a hole for introducing the ions 30 generated in the ion source 15 into the container 210. The first pore 51 can also be considered to be provided in a vacuum container consisting of the first pore plate 50 and the container 210.

[0027] In the path of the ions passing through the first pore 51 in the container 210, the second pore plate 70, the intermediate lens 90, the adjustment lens 110, the in-cap electrode 130, the quadruple electrode 150, and the out-cap 170 are arranged in order. Each of these has a hole through which the ions pass. As the hole, the second pore plate 70 has the second pore 71 which is a through hole. The in-cap electrode 130, the quadruple electrode 150, and the out-cap 170 provided in the container 210 constitute the ion trap section 300. The second pore 71, the intermediate lens 90, and the adjustment lens 110 are provided in order between the first pore 51 and the ion trap section 300, and have the role of transporting the ions, which are the sample introduced into the container 210, to the ion trap section.

[0028] A detector 190 that detects ions using a quadruple electrode 150 is provided inside or outside the container 210, and the detector 190 is connected to a signal detection board 230 outside the container 210, which is connected to an equipment control board 250, which is connected to a control unit 500 via a communication line.

[0029] Here, the location where the measurement sample (sample gas) is supplied from the heating unit 1 and the location where the electric charge is applied by the high voltage application unit 20 (location where corona discharge occurs) are the same, but these locations (rooms) may be separate. For example, there may be a location where the sample gas is supplied between the location where the electric charge is applied by the high voltage application unit 20 and the first pore plate 50.

[0030] <Mass spectrometer operation> Next, the operation of the mass spectrometer will be described. When performing an inspection using the mass spectrometer, first, chemical substances adhering to the inspection target material are wiped off. Next, the wiped off material is heated and vaporized by the heating unit 1. The heated and gasified sample passes through the sample air supply tube 10 and is introduced into the ion source 15. An electric charge is applied to the introduced gas by the high voltage application unit 20 in the ion source 15, and the gas becomes ions 30. Since the ions have an electric charge, this ionization makes it possible to electromagnetically control the ions. The ions pass through the first pore 51 of the first pore plate 50 and are introduced into the container 210 (mass analysis unit).

[0031] Here, the inside of the ion source 15 is at atmospheric pressure, whereas the inside of the container 210 is at vacuum. That is, the boundary between the atmosphere and the vacuum inside the container 210 is the first pore 51. In other words, the vacuum inside the container 210 is maintained by the first pore plate 50 and the container 210.

[0032] The ions then pass through the second aperture plate 70, and the ion trajectory is focused by the intermediate lens 90, and the ions are introduced into the ion trap section 300. The kinetic energy of the ions in the ion trajectory focused by the intermediate lens 90 is sufficiently reduced, and the ions pass through the adjusting lens 110 and head toward the ion trap section 300.

[0033] The adjusting lens 110 is an ion focusing lens consisting of three electrode plates arranged at a distance from each other in the direction of ion travel. A through hole with a diameter of about 2 mm is provided in the center of each electrode plate. Of the three arranged electrode plates, a positive or negative control voltage is applied to the center electrode, and a ground voltage is applied to each of the two electrode plates sandwiching this electrode. By selecting the positive or negative voltage applied to the center electrode, it is possible to select whether positive ions or negative ions are allowed to pass.

[0034] Ions passing through the adjusting lens 110 can be controlled with a low electric field intensity because the ion trajectory is converged and the kinetic energy is reduced. Therefore, the voltage applied to the adjusting lens 110 is also reduced. As a result, the voltage switching time required to control the amount of ions introduced is shortened and fine adjustment of the control amount is also facilitated. That is, the adjusting lens 110 has a function of controlling the amount of ions passing through the adjusting lens 110. In other words, in the adjusting lens 110, the amount of ions passing through the adjusting lens 110 is controlled by the control unit 500 connected to the mass spectrometer 540. The adjusting lens 110 is connected to the control unit 500.

[0035] The adjusting lens 110 is provided for the purpose of controlling the amount of ions introduced into the ion trap section 300. For this reason, the adjusting lens 110 is provided immediately before the ion trap section 300 in the path of ions from the first aperture 51 toward the ion trap section 300. In other words, no other lenses (electrodes) are provided between the adjusting lens 110 and the ion trap section 300.

[0036] Ions that have passed through the adjustment lens 110 are introduced into the ion trap section 300, where they are trapped and ejected for ion separation. The ion trap section 300 is installed in a high vacuum section that enables mass separation. The separated ions are converted into an electric signal by the detector 190 and transmitted to the signal detection board 230. An ion detection signal is transmitted to and received from the control section 500 via the device control board 250 that controls the signal detection board 230 and the mass spectrometer 540. The control section 500 generates a mass spectrum and performs arithmetic processing such as quantitative calculation, and the measurement results are output to the screen of the control section 500.

[0037] That is, a signal measured by the mass spectrometer 540 is transmitted from the mass spectrometer 540 to the control unit 500, and the control unit 500 performs data analysis and qualitative and quantitative numerical calculations from the signal.

[0038] A detection target sample table (see FIG. 2) is stored in advance in the memory unit 510, and the detection amount (detection concentration information) of various regulations and the control voltage value of the adjustment lens 110 are stored for each target sample. The target samples referred to here are the types of samples to be detected, such as chemical substances x, y, z, x+y, x+z, and y+z shown in FIG. 2. Chemical substance x+y represents, for example, a case where chemical substance x and chemical substance y are to be detected. The detection amount of various regulations is the amount of the chemical substance required to detect the chemical substance.

[0039] For example, the detectable amount of chemical substance x is 0.1 ng, and when the detectable amount in the measurement sample exceeds 0.1 ng, the control unit 500 displays a message indicating that the amount has been exceeded. When there are multiple samples to be detected, multiple control voltages for the adjustment lens 110 are also stored in the detection sample table, and these control voltages are switched during measurement. This allows, for example, chemical substance x and chemical substance y to be detected in a single measurement.

[0040] <Effects of the embodiment> In the mass spectrometer of this embodiment, the detection amount, which is the threshold value for each detection target sample shown in Fig. 2, and the control voltage are stored (saved) in the memory unit 510 of the control unit 500. The amount of ions introduced into the ion trap unit 300 can be adjusted by applying a control voltage corresponding to the detection target sample to an electrode of the adjustment lens 110 and changing the voltage of the electrode. For example, when it is desired to detect low concentration ions, the amount of high concentration ions passing through the adjustment lens 110 can be reduced. This makes it possible to reduce the amount of high concentration ions that accumulate in the ion trap unit 300 per unit time.

[0041] Here, different detection amount thresholds are stored in the memory unit 510 for each detection target sample. This maintains the linear relationship between the amount of ions and the concentration, whether the ions are in high or low concentration. In other words, quantitativeness is maintained. Furthermore, even for low concentrations of the measurement target substance, the linear relationship between the amount of ions and the detection signal is not lost, and mass spectrometry data can be obtained at the same measurement time interval.

[0042] The chemical substance x shown in FIG. 2 has a relatively small ion mass, and can be detected with as little as 0.1 ng. Therefore, by increasing the absolute value of the voltage applied to the adjustment lens to, for example, 5 V, it can be selectively detected. The positive and negative of the applied voltage depends on the charge state of the ions to be passed. By changing the control voltage applied to the adjustment lens 110 during measurement, both substance x and substance y can be selectively detected. In other words, multiple samples can be detected with one measurement (sampling).

[0043] FIG. 3 shows a graph of the relationship between the control voltage and the signal intensity. The horizontal axis of FIG. 3 indicates the type of sample, and the vertical axis indicates the signal intensity (sensitivity). The voltage (unit: V) shown in the graph in FIG. 3 is the voltage stored in the memory unit 510 and indicates the control voltage applied to the adjustment lens 110. As shown in FIG. 3, the sensitivity can be appropriately adjusted by changing the control voltage, for example, from 0V to -5V. That is, it can be seen that when a control voltage of -5V is applied, the sensitivity is improved by about 7.5 times compared to when the control voltage is 0V (ground level). This is the same even when the applied voltage is a positive value. By adjusting the sensitivity in this way, the amount of ions passing through can be controlled according to the concentration. For example, if the absolute value of the applied voltage is lowered, the sensitivity is lowered, and chemical substances with large detection amounts can be selectively detected.

[0044] Thus, according to this embodiment, ions generated in the ion source are introduced into the mass spectrometer, and the ion trajectory converges through the first aperture, the second aperture, and the intermediate lens, and the ion kinetic energy decreases. By controlling the voltage of the ion adjustment lens provided immediately before the ion trap section, the amount of ions introduced into the ion trap section can be adjusted. Furthermore, since the ion kinetic energy is reduced, control with a low voltage is possible, and the voltage can be switched in a short time. The measurement target substance (target substance to be measured) and the detected concentration (detected amount, detected concentration information) are stored in the control unit (storage unit) in advance, and by using this information, the ion adjustment lens is controlled so that the amount of ions passing through the adjustment lens is reduced when the detected concentration of the measurement target substance is high, and the amount of ions passing through is increased when the detected concentration is low. In other words, the voltage applied to the adjustment lens is controlled based on the detected concentration information, and the amount of ions introduced into the ion trap section is thereby controlled.

[0045] With these configurations, the amount of ions introduced into the ion trap is controlled regardless of the concentration of the target substance to be measured, and the linear relationship between the amount of ions and the detection signal is maintained.Furthermore, it is possible to provide a mass spectrometer that can perform measurements at the same time interval and maintain the data accuracy of the chromatography data.

[0046] As a result, it is possible to eliminate the first room for improvement of maintaining the linear relationship between the amount of ions and the concentration regardless of the concentration of the sample, the second room for improvement of the difficulty of identifying a substance by comparing it with a mass spectrum previously acquired when multiple samples are mixed, and the third room for improvement of identifying multiple types of chemical substances in a single measurement. In other words, it is possible to obtain mass spectrometry data at the same measurement time interval without losing the linear relationship between the amount of ions and the detection signal, whether the target substance is a high concentration or a low concentration. Furthermore, it is possible to detect multiple chemical substances with different target concentrations in a single sampling.

[0047] (Embodiment 2) In this embodiment, in addition to the configuration of the above-mentioned embodiment 1, an internal standard sample is ionized simultaneously with the measurement sample when higher quantitative accuracy is required. During actual measurement, ionization of the measurement target substance may be suppressed due to ionization of chemical substances other than the measurement target substance present on the wiped surface, or samples other than the measurement target substance originating from the environment in which the device is placed. By using a sample with a known concentration and subject to the same suppression effect as the measurement target substance as the internal standard sample, the proportion of the ionization of those substances that is suppressed can be obtained, and the suppression effect can be corrected.

[0048] In the present embodiment shown in Fig. 4, in addition to the configuration described with reference to Fig. 1, an internal standard sample introduction section 5 for introducing an internal standard sample gas is provided. The measurement sample introduced into the ion source 15 through the sample air delivery tube 10 and the internal standard sample gas introduced into the ion source 15 through the internal standard sample introduction section 5 are mixed in the ion source 15, and an electric charge is applied to them, forming ions 30. The internal standard sample may be introduced into the ion source 15 through the same piping as the measurement sample. Subsequent operations are the same as those of the first embodiment.

[0049] The amount of ions in the internal standard sample is controlled when it passes through the adjustment lens 110 together with the measurement sample. The amount of ions passing through is determined by the control voltage applied to the adjustment lens 110. Since the transmittance of the internal standard sample and the measurement sample through the adjustment lens 110 is almost constant depending on the voltage, the rate at which ionization is suppressed is maintained, and it is possible to correct the suppression effect due to ionization of substances other than the measurement target substance. This improves the quantitative accuracy of detection of the measurement target substance in this embodiment. In addition, by applying a control voltage suitable for the target chemical substance to the adjustment lens during measurement, it becomes possible to detect multiple target chemical substances.

[0050] In addition, the configuration in which an adjustment lens is provided immediately before the linear ion trap section can also be used in so-called hybrid mass spectrometers that use an ion trap section, such as a linear trap / time-of-flight mass spectrometer or a triple quadrupole mass spectrometer.

[0051] The invention made by the present inventors has been specifically described above based on an embodiment, but it goes without saying that the present invention is not limited to the above embodiment and can be modified in various ways without departing from the gist of the invention. [Explanation of symbols]

[0052] 1 Heating section 5. Internal standard sample introduction section 10 Sample air pipe 15 Ion source 20 High voltage application section 30 Aeon 50 First pore plate 51 First hole 70 Second pore plate 71 Second hole 90 Intermediate Lens 110 Adjustable Lens 130 In-cap electrode 150 Quadruple electrode 170 Out Cap 190 Detector 210 Container 230 Signal detection board 250 Device control board 300 Ion trap section 500 Control section 510 Storage section 540 Mass spectrometer

Claims

1. An ion trap type mass spectrometer that ionizes a sample attached to an object to be inspected and separates the ions based on their mass and charge, A heating unit for heating and vaporizing the sample; a first gas supply pipe for introducing the sample vaporized by the heating unit into an ion source; the ion source applying an electric charge to the sample; A container having an internal vacuum state; a first aperture for introducing the sample ionized by the ion source into the container; an ion trap section provided in the container; a second aperture, an intermediate lens, and an adjustment lens that are provided in this order between the first aperture and the ion trap section and that transport the ions, which are the sample introduced into the container, to the ion trap section; Equipped with The first pore is a boundary between atmospheric pressure and vacuum pressure, A mass spectrometer, wherein the amount of ions passing through the adjustment lens is controlled by a control unit connected to the mass spectrometer.

2. 2. The mass spectrometer of claim 1, The adjusting lens is provided immediately before the ion trapping section in a path of ions from the first aperture toward the ion trapping section.

3. 2. The mass spectrometer of claim 1, The control unit is A mass spectrometer comprising a memory unit that prestores detected concentration information of a substance to be measured, and controls a voltage applied to the adjustment lens based on the detected concentration information, thereby controlling the amount of ions introduced into the ion trap unit.

4. 4. The mass spectrometer according to claim 3, The apparatus further includes a second gas supply pipe for introducing an internal standard sample used for correcting the ionization state into the ion source, In the ion source, a charge is applied to a gas mixture of the sample and the internal standard sample; The control unit controls the voltage of the adjustment lens based on the detected concentration information, thereby controlling the respective amounts of ions derived from the sample and ions derived from the internal standard sample to be introduced into the ion trap unit.

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