Analysis device and analysis method

Abstract

The present invention acquires analysis results relating to the mass concentration and the elements of an analysis object in a short time and with a simple device configuration. An analysis device (100) comprises a β ray source (51), a detection unit (7, 7', 7"), and an analysis unit (9). The β ray source (51) irradiates the analysis object with β rays. The detection unit (7, 7', 7") simultaneously detects transmitted β rays that have passed through the analysis object and fluorescent X-rays that have been produced by irradiating the analysis object with the β rays, and outputs detection signals. The analysis unit (9) acquires, from the detection signals, a first signal produced by detecting the transmitted β rays and a second signal produced by detecting the fluorescent X-rays. The analysis unit (9) calculates information relating to the mass concentration of the analysis object on the basis of the first signal, and calculates information relating to the elements included in the analysis object on the basis of the second signal.

Description

Analysis device and analysis method

[0001] The present invention relates to an analyzer that performs analysis of the mass concentration of an analyte and the elements contained in the analyte, and to a method for analyzing the analyte using the analyzer.

[0002] Known devices for analyzing an analyte include those that measure the mass concentration of the analyte based on the amount of beta rays that pass through the analyte, and that can analyze elements contained in the analyte based on fluorescent X-rays emitted from the analyte (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2005-134270

[0004] In the above-described device, the particulate matter to be analyzed is collected on a collection filter to measure its mass concentration, and then the collection filter is moved to change the particulate matter collection area. At the new location, fluorescent X-rays are generated from the particulate matter, and the elements contained in the particulate matter are analyzed. In other words, in conventional devices, a location for measuring mass concentration and a location for analyzing elements are provided separately. This can lead to complex device configurations. Furthermore, because mass concentration and elemental analysis are performed separately, it takes a certain amount of time to obtain analysis results, and this may prevent faster acquisition of analysis results.

[0005] An object of the present invention is to obtain analytical results regarding the mass concentration and elements of an analysis target in a short time using a simple device configuration.

[0006] Below, several aspects will be described as means for solving the problems. These aspects can be combined as needed. An analytical device according to one aspect of the present invention includes a β-ray source, a detection unit, and an analysis unit. The β-ray source irradiates an object to be analyzed with β-rays. The detection unit simultaneously detects transmitted β-rays that have passed through the object to be analyzed and fluorescent X-rays generated by irradiating the object to the β-rays, and outputs a detection signal. The analysis unit obtains, from the detection signal, a first signal generated by detecting the transmitted β-rays and a second signal generated by detecting the fluorescent X-rays. The analysis unit also calculates information regarding the mass concentration of the object to be analyzed based on the first signal, and calculates information regarding the elements contained in the object to be analyzed based on the second signal.

[0007] The inventors of the present invention discovered that when an analyte is irradiated with beta rays, passing beta rays that pass through the analyte are generated, and at the same time, fluorescent X-rays are generated from the analyte. In the above-described analytical device, the detection unit simultaneously detects the passing beta rays and the fluorescent X-rays and outputs a detection signal. That is, the detection signal includes a first signal derived from the passing beta rays and a second signal derived from the fluorescent X-rays. Furthermore, the analysis unit calculates information regarding the mass concentration of the analyte based on the first signal, and calculates information regarding the elements contained in the analyte based on the second signal.

[0008] In this way, the above-described analytical device can calculate information about the mass concentration of an object to be analyzed and information about elements contained in the object to be analyzed with a simple device configuration. Furthermore, because the detection unit can simultaneously detect transmitted beta rays and fluorescent X-rays, the analysis results of the object to be analyzed (information about the mass concentration and elements contained in the object to be analyzed) can be obtained in a short time.

[0009] The detection unit may have a first scintillator, a second scintillator, and a light detection unit. The first scintillator is disposed opposite the beta-ray source and generates a first light when passing beta rays are incident thereon. The second scintillator is disposed opposite the beta-ray source and generates a second light when fluorescent X-rays are incident thereon. The light detection unit detects the first light and the second light and outputs a detection signal. This allows the passing beta rays and fluorescent X-rays to be converted into the first light and the second light, respectively, and allows the passing beta rays and fluorescent X-rays to be easily detected.

[0010] The light detection unit may include a first photodetector that detects the first light and outputs a first signal, and a second photodetector that detects the second light and outputs a second signal. This allows the first light and the second light to be simultaneously detected by separate photodetectors. As a result, the first signal and the second signal can be acquired more simply without performing signal separation processing on the acquired signals.

[0011] The light detection unit may include a third light detector that detects both the first light and the second light and outputs a detection signal. This allows the first light and the second light to be detected by a single light detector, thereby simplifying the device configuration.

[0012] The analysis unit may separate the first signal and the second signal from the detection signal based on the pulse width of the detection signal, thereby enabling the first signal and the second signal to be accurately separated using the pulse width of the detection signal.

[0013] The analysis unit may separate the first signal and the second signal from the detection signal based on the peak intensity of the detection signal, thereby enabling the first signal and the second signal to be accurately separated using the intensity of the detection signal.

[0014] The analysis target may be particulate matter. In this case, the analysis device may further include a collection device that collects the particulate matter in a collection filter. The β-ray source and the detection unit may be provided in the collection device. This allows the mass concentration of the particulate matter and information about the elements contained in the particulate matter to be calculated in a short period of time. Furthermore, providing the β-ray source and the detection unit in the collection device allows the analysis device to be made compact.

[0015] An analytical method according to another aspect of the present invention comprises the following steps: A step of irradiating an object to be analyzed with beta rays. A step of simultaneously detecting transmitted beta rays that have passed through the object to be analyzed and fluorescent X-rays generated by irradiating the object to be analyzed with beta rays, and outputting detection signals. A step of acquiring, from the detection signals, a first signal generated by detecting the transmitted beta rays and a second signal generated by detecting the fluorescent X-rays. A step of calculating information regarding the mass concentration of the object to be analyzed based on the first signal, and calculating information regarding the elements contained in the object to be analyzed based on the second signal.

[0016] In the above analytical method, transmitted beta rays and fluorescent X-rays generated by irradiating an analyte with beta rays are simultaneously detected, and a detection signal is output. That is, the detection signal includes a first signal derived from the transmitted beta rays and a second signal derived from the fluorescent X-rays. Furthermore, in the above analytical method, information regarding the mass concentration of the analyte is calculated based on the first signal, and information regarding the elements contained in the analyte is calculated based on the second signal.

[0017] In this way, in the above analysis method, transmitted beta rays and fluorescent X-rays are detected simultaneously, so that the analysis results of the analysis target (information on the mass concentration and elements contained in the analysis target) can be obtained in a short time.

[0018] Analysis results regarding the mass concentration and elements of the analysis target can be obtained in a short time using a simple device configuration.

[0019] Fig. 1 is a diagram showing the configuration of an analytical device. Fig. 2 is a diagram showing the detailed configuration of a β-ray irradiation unit and a detection unit. Fig. 3 is a flowchart showing the analysis operation in the analytical device. Fig. 4 is a diagram showing an example of a verification result of whether fluorescent X-rays can be generated and detected from an analysis target. Fig. 5 is a diagram showing the configuration of a detection unit of a second embodiment. Fig. 6 is a diagram showing the configuration of a detection unit of a third embodiment.

[0020] 1. First Embodiment (1) Overview of the Analytical Device The analytical device 100 analyzes, for example, particulate matter FP generated by combustion processes in factories, brakes of various transportation devices (automobiles, ships, etc.), tires, internal combustion engines, steam engines, exhaust gas purification devices and motors, natural disasters such as volcanic eruptions, mining development, and particulate matter FP contained in the atmosphere. For example, particulate matter FP containing silver (Ag), tin (Sn), etc. can be analyzed. The analytical device 100 can acquire, as analysis results, the mass concentration of the particulate matter FP and information about the elements contained in the particulate matter FP (for example, the elements contained and the content of those elements).

[0021] "Mass concentration of particulate matter FP" is defined as the mass of particulate matter contained in the total volume of collected gas, expressed as a value per unit volume of collected gas, e.g., μg / m 3 is used as a unit.

[0022] On the other hand, the "content of element" has the following two definitions. In the first definition, the "content of element" is defined as the mass of a target element (or substance) contained in the total mass of collected particulate matter FP, expressed as the ratio of the mass of the target element (substance) contained to the total weight of the particulate matter (units: mg / mg, for example). In the second definition, the "content of element" is defined as the amount of a specific element contained in particulate matter contained in the total volume of collected gas, expressed as a value per unit volume of gas (units: ng / m, for example). 3 ).

[0023] (2) Configuration of the Analysis Device The configuration of the analysis device 100 will be described below with reference to Figures 1 and 2. Figure 1 is a diagram showing the configuration of the analysis device. Figure 2 is a diagram showing the detailed configuration of the β-ray irradiation unit and detection unit. The analysis device 100 includes a collection filter 1, a collection device 3, a β-ray generation unit 5, a detection unit 7, and an analysis unit 9.

[0024] The collection filter 1 is a tape-shaped member formed by laminating a collection layer (sometimes referred to as a collection region) made of a porous fluororesin material having pores capable of capturing particulate matter FP on a reinforcing layer made of a nonwoven fabric of a polymer material (such as polyethylene). This configuration allows gas to flow through the collection filter 1 in the thickness direction, while improving its strength. It is also possible to make the collection filter 1 less susceptible to electrostatic charge. Other filters, such as a single-layer glass filter or a single-layer fluororesin material filter, can also be used as the collection filter 1.

[0025] For example, one end of the collection filter 1 in the longitudinal direction is connected to a take-up reel 11a, and the other end is connected to a supply reel 11b. The take-up reel 11a can be rotated in a predetermined direction by, for example, a motor (not shown). With this configuration, by rotating the take-up reel 11a, the collection filter 1 is fed from the supply reel 11b and taken up by the take-up reel 11a. In other words, by rotating the take-up reel 11a, the collection filter 1 can be moved in the longitudinal direction of the collection filter 1 (the direction indicated by the thick arrow in FIG. 1 ).

[0026] The mechanism for moving the collection filter 1 is not limited to the above mechanism. For example, a pin may be provided in the longitudinal direction of the collection filter 1, and this pin may be used to change the direction of movement of the collection filter 1. Furthermore, the collection filter 1 may be provided with a tension controller that adjusts its tension.

[0027] The collection device 3 causes the collection filter 1 to collect particulate matter FP suspended in the measurement atmosphere. The collection device 3 has a suction member 31 and a discharge member 33. The suction member 31 is disposed directly below the surface of the collection filter 1 on the reinforcing layer side. The suction member 31 is formed with a first opening 31a connected to a suction pump 35.

[0028] The discharge member 33 is disposed in a position facing the suction member 31, directly above the surface of the collection filter 1 facing the collection region. A second opening 33a is formed in the discharge member 33 so as to face the first opening 31a. The second opening 33a can discharge the particulate matter FP collected via the collection member 37 toward the collection filter 1 by the suction force of the first opening 31a. The particulate matter FP discharged from the discharge member 33 is collected by the collection filter 1.

[0029] The collection member 37 may have various devices for collecting the particulate matter FP. For example, when the particulate matter FP in the atmosphere is the target of analysis, the collection member 37 may have a classifier that classifies the particulate matter FP. Furthermore, when the particulate matter FP in exhaust gas is the target of analysis, the collection member 37 may have a sampling unit (for example, a sampling probe).

[0030] The β-ray generating unit 5 is disposed at the second opening 33a of the discharge member 33, and irradiates β-rays onto the particulate matter FP trapped on the collection filter 1. As shown in FIG. 2, the β-ray generating unit 5 has a β-ray source 51. The β-ray source 51 irradiates β-rays onto the particulate matter FP trapped on the collection filter 1. The β-ray source 51 is, for example, a carbon-14 ( 14 C), Strontium 90 ( 90 Sr), Promethium 147 ( 147Pm) By using these as the β-ray source 51, it is possible to suppress the generation of unnecessary radiation such as γ-rays.

[0031] The β-ray generating unit 5 may have a limiting member 53. The limiting member 53 adjusts the intensity of the β-rays irradiated toward the particulate matter FP by blocking a portion of the β-rays generated from the β-ray source 51. The limiting member 53 is, for example, a plate-shaped member made of acrylic.

[0032] The detection unit 7 can be disposed, for example, in the first opening 31a of the suction member 31. This allows the detection unit 7 to be disposed opposite the β ray generation unit 5. The detection unit 7 detects β rays (referred to as transmitted β rays) that are generated from the β ray generation unit 5 and that have passed through the particulate matter FP and the collection filter 1, and fluorescent X-rays that are generated by irradiating the particulate matter FP with β rays. As shown in FIG. 2 , the detection unit 7 of this embodiment simultaneously detects the particulate matter FP, β rays that have passed through the collection filter 1, and fluorescent X-rays generated from the particulate matter FP using separate detectors. Specifically, the detection unit 7 has a first scintillator 71, a first photodetector 73, a second scintillator 75, and a second photodetector 77.

[0033] The first scintillator 71 can be disposed, for example, at the first opening 31 a so as to face the β ray generating unit 5. The first scintillator 71 generates light in response to passing β rays. The first scintillator 71 is a component that generates light when passing β rays are incident on it, and is, for example, a scintillator made of a low-density material such as a plastic scintillator made of polyvinyl toluene.

[0034] The first photodetector 73 detects light (referred to as first light) generated in the first scintillator 71 and outputs a first signal. That is, the first photodetector 73 outputs a first signal by detecting β rays passing through the first scintillator 71. The first photodetector 73 is a detector that detects light and outputs a signal, such as a SiPM (Silicon PhotoMultiplier), a photomultiplier tube, or a silicon semiconductor detector.

[0035] The second scintillator 75 is disposed below the first scintillator 71, facing the β ray generating unit 5 at the first opening 31a. The second scintillator 75 generates light in response to fluorescent X-rays that are generated from the particulate matter FP and pass through the first scintillator 71. The second scintillator 75 is a member that generates light when X-rays are incident thereon, and is a member made of an inorganic material such as cesium iodide (CsI) or sodium iodide (NaI).

[0036] The second photodetector 77 detects light (referred to as second light) generated in the second scintillator 75 and outputs a second signal. That is, the second photodetector 77 outputs a first signal by detecting fluorescent X-rays generated from the particulate matter FP in the second scintillator 75. The second photodetector 77 is a detector that detects light and outputs a signal, such as a SiPM (Silicon PhotoMultiplier), a photomultiplier tube, or a silicon semiconductor detector.

[0037] The detection unit 7 further includes a light-shielding member 79. The light-shielding member 79 prevents external light from entering the detection unit 7. That is, the light-shielding member 79 prevents external light from entering the first photodetector 73 and the second photodetector 77. This makes it possible to prevent light other than the light (first light, second light) generated by the scintillator from entering the first photodetector 73 and the second photodetector 77. As a result, transmitted beta rays and fluorescent X-rays generated from the particulate matter FP can be detected more accurately.

[0038] The analysis unit 9 is a computer system having a CPU, RAM, ROM, storage devices such as HDD and SSD, various interfaces, a display, etc. The analysis unit 9 controls each component of the analysis device 100 and performs various information processing related to the analysis device 100. The analysis unit 9 has a calculation unit 91 and a display unit 93.

[0039] The calculation unit 91 is composed of the CPU, storage device, and various interfaces of the analysis unit 9, and controls each component of the analysis device 100 and performs various information processing related to the analysis device 100. The calculation unit 91 controls each component of the analysis device 100 and performs various information processing related to the analysis device 100 using software that is stored in the storage device of the computer system that constitutes the analysis unit 9 and is executable by the analysis unit 9. The calculation unit 91 may also perform some of the above control and information processing using hardware.

[0040] Specifically, the calculation unit 91 controls the suction pump 35 to cause the collection filter 1 to collect the particulate matter FP. The calculation unit 91 also controls the motor that rotates the take-up reel 11a to control the longitudinal movement of the collection filter 1. The calculation unit 91 controls the β-ray source 51 to control the β-rays irradiated onto the particulate matter FP. The calculation unit 91 calculates information regarding the mass concentration of the particulate matter FP based on the first signal input from the first photodetector 73. The calculation unit 91 also calculates information regarding the elements contained in the particulate matter FP based on the second signal input from the second photodetector 77.

[0041] The display unit 93 is a display of the analysis unit 9, and displays various information related to the analysis device 100 and the analysis results of the particulate matter FP (information related to mass concentration, information related to elements). The display unit 93 is, for example, a liquid crystal display, an organic EL display, or the like.

[0042] (3) Analysis Operation in the Analysis Apparatus The analysis operation of the particulate matter FP in the analysis apparatus 100 will be described using Figure 3. Figure 3 is a flowchart showing the analysis operation in the analysis apparatus. First, a process is executed to collect particulate matter FP suspended in the measurement atmosphere on the collection filter 1 (step S1). Specifically, the calculation unit 91 of the analysis unit 9 operates the suction pump 35 to collect the particulate matter FP on the collection filter 1.

[0043] During the collection operation or after the particulate matter FP has been collected for a predetermined time, the calculation unit 91 generates beta rays from the beta ray source 51 (step S2). As a result, the particulate matter FP is irradiated with beta rays. A portion of the beta rays irradiated onto the particulate matter FP passes through the particulate matter FP and the collection filter 1 and enters the detection unit 7. Furthermore, by irradiating the particulate matter FP with beta rays, fluorescent X-rays are generated from the particulate matter FP, pass through the collection filter 1, and enter the detection unit 7.

[0044] While the particulate matter FP is irradiated with beta rays, the calculation unit 91 detects the beta rays and fluorescent X-rays incident on the detection unit 7 (step S3). The transmitted beta rays that have passed through the particulate matter FP and the collection filter 1 are incident on the first scintillator 71, causing light (first light) to be generated in the first scintillator 71. The first photodetector 73, which detects the first light, outputs a first signal. The calculation unit 91 receives this first signal from the first photodetector 73 as a signal representing the intensity of the transmitted beta rays.

[0045] As described above, the first scintillator 71 is made of a low-density material such as a plastic scintillator. In this case, most of the transmitted beta rays do not pass through the first scintillator 71, while the fluorescent X-rays from the particulate matter FP pass through the first scintillator 71 and are incident on the second scintillator 75. As a result, the second scintillator 75 generates a second light caused by the fluorescent X-rays. The second photodetector 77 detects the second light and outputs a second signal. The calculation unit 91 receives this second signal from the second photodetector 77 as a signal representing the intensity of the fluorescent X-rays generated from the particulate matter FP.

[0046] After acquiring the first signal corresponding to the passing beta rays and the second signal corresponding to the fluorescent X-rays from the particulate matter FP, the calculation unit 91 performs an analysis of the particulate matter FP based on these signals (step S4). Specifically, the calculation unit 91 calculates the mass concentration of the particulate matter FP based on, for example, the intensity of the passing beta rays represented by the first signal. Furthermore, the calculation unit 91 identifies elements contained in the particulate matter FP based on, for example, the energy and intensity of the fluorescent X-rays represented by the second signal, and calculates the content of the elements in the particulate matter FP.

[0047] When the analysis of the particulate matter FP is completed, the calculation unit 91 displays the analysis results of the particulate matter FP on the display unit 93. Furthermore, for example, when the mass concentration of the particulate matter FP exceeds a predetermined threshold, when the particulate matter FP contains a specific element at a predetermined content or more, etc. The calculation unit 91 may issue an alarm. For example, the alarm can be issued by displaying an alarm on the display unit 93, emitting a sound, or the like.

[0048] After the analysis is completed, for example, if a command to stop the analysis of the particulate matter FP is given ("Yes" in step S5), the analysis operation in the analyzer 100 stops. On the other hand, if a command to stop the analysis of the particulate matter FP is not given ("No" in step S5), the analysis operation in the analyzer 100 continues. Specifically, the calculation unit 91 moves the collection filter 1 in the lengthwise direction by rotating the take-up reel 11a, and positions the portion of the collection filter 1 where no particulate matter FP has been collected directly below the discharge member 33. Thereafter, the above steps S1 to S4 are performed to perform a new analysis of the particulate matter FP.

[0049] In this way, by detecting the intensity of the passing beta rays with the first photodetector 73 and detecting the fluorescent X-rays generated from the particulate matter FP with the second photodetector 77, the passing beta rays generated by irradiating the particulate matter FP with beta rays and the fluorescent X-rays from the particulate matter FP can be detected in situ. That is, the calculation unit 91 can simultaneously acquire a first signal for calculating information related to the mass concentration of the particulate matter FP and a second signal for calculating information related to the elements contained in the particulate matter FP. As a result, the analysis results of the particulate matter FP (information related to mass concentration, information related to elements) can be acquired in a short time.

[0050] Furthermore, by detecting the transmitted β rays and the fluorescent X-rays with separate photodetectors, it is possible to separately acquire a first signal corresponding to the transmitted β rays and a second signal corresponding to the fluorescent X-rays. As a result, it is possible to acquire the first signal and the second signal more simply without performing signal separation processing on the acquired signals.

[0051] (4) Example The following describes the results of verifying whether fluorescent X-rays can be generated from an analysis object by irradiating the analysis object with β-rays and whether they can be detected by a photodetector. In this example, a lead (Pb) plate was used as the analysis object. Carbon-14 ( 14 C) was used. A scintillator made of cesium iodide (CsI) was used as a scintillator for detecting fluorescent X-rays generated by irradiating an analysis target with beta rays generated from this beta-ray source. Light generated from this scintillator was detected by a photodetector (e.g., a SiPM (Silicon PhotoMultiplier), a photomultiplier tube, a silicon semiconductor detector, etc.).

[0052] Figure 4 shows an example of the results of a verification of whether fluorescent X-rays can be generated and detected from an analysis target by irradiating the analysis target with beta rays. As shown in Figure 4, when the analysis target (lead plate) was irradiated with beta rays, the photodetector was able to detect a significant X-ray intensity relative to the background at the energy value of the Kα rays of lead (Pb). In other words, the photodetector was able to detect fluorescent X-rays generated when the analysis target was irradiated with beta rays. Note that the background corresponds to the intensity of light (X-rays) detected by the photodetector when no beta rays were generated from the beta-ray source.

[0053] 2. Second Embodiment In the first embodiment described above, the passing beta rays and the fluorescent X-rays are detected by separate detectors. However, this is not limiting, and the passing beta rays and the fluorescent X-rays can also be detected by a common detector. In the second embodiment in which the passing beta rays and the fluorescent X-rays are detected by a common detector, the detection unit 7' has a first scintillator 71, a second scintillator 75, and a third photodetector 81, as shown in FIG. 5. FIG. 5 is a diagram showing the configuration of the detection unit of the second embodiment.

[0054] The first scintillator 71 and the second scintillator 75 of the detection unit 7' are the same as those in the first embodiment, and therefore description thereof will be omitted here. The third photodetector 81 is disposed below the second scintillator 75 and simultaneously detects a first light generated when passing β rays are incident on the first scintillator 71 and a second light generated when fluorescent X-rays are incident on the second scintillator 75. The third photodetector 81 is a detector that detects light and outputs a signal, such as a SiPM (Silicon PhotoMultiplier), a photomultiplier tube, or a silicon semiconductor detector.

[0055] In this way, by detecting the first light and the second light using a single detector, the number of detectors for detecting transmitted beta rays and fluorescent X-rays can be reduced, making the device configuration of the analysis device 100 simpler.

[0056] As described above, the third photodetector 81 simultaneously detects the first light and the second light. Therefore, the detection signal output from the third photodetector 81 by detecting these lights is a signal obtained by adding together a first signal caused by the first light (passed β rays) and a second signal caused by the second light (fluorescent X-rays). In order to measure the passed β rays and fluorescent X-rays from this detection signal, the calculation unit 91 separates the first signal and the second signal from this detection signal.

[0057] In a radiation detection unit using a scintillator, a pulsed detection signal is output from the photodetector when radiation is detected. The peak intensity of the pulsed detection signal corresponds to the energy of the detected radiation. Furthermore, the number of pulsed detection signals per unit time corresponds to the intensity of the detected radiation. Furthermore, the energy value of the fluorescent X-rays emitted from the analysis target is specific to the elements contained in the analysis target.

[0058] Using the above characteristics, the calculation unit 91 separates a first signal resulting from passing beta rays and a second signal resulting from fluorescent X-rays based on the peak intensity of the pulsed detection signal output from the third photodetector 81. Specifically, the calculation unit 91 can separate the first signal from the second signal as follows, for example. The calculation unit 91 first identifies the peak intensity of the input pulsed detection signal and calculates an energy value corresponding to this peak intensity. If the calculated energy value does not correspond to the energy value of the fluorescent X-rays of an element predicted to be contained in the analysis target, the calculation unit 91 can determine that the detection signal is the first signal.

[0059] On the other hand, if the calculated energy value corresponds to the energy value of the fluorescent X-rays of an element predicted to be contained in the analysis target, the calculation unit 91 can calculate the second signal (the count value of the detection signal caused by the fluorescent X-rays) by subtracting the count value corresponding to the intensity of the component of the passing beta rays having that energy value from the count value of the detection signal.

[0060] In addition, the pulse width of the detection signal also corresponds to the energy value of the detected radiation. Therefore, the calculation unit 91 can also separate the first signal and the second signal based on the pulse width of the detection signal output from the third photodetector 81. For example, the calculation unit 91 identifies the pulse width of the input pulsed detection signal and calculates the energy value corresponding to this pulse width. If the calculated energy value does not correspond to the energy value of the fluorescent X-rays of the element predicted to be contained in the analysis target, the calculation unit 91 can determine that the detection signal is the first signal. Note that the second signal can be separated using the same method as above.

[0061] 3. Third Embodiment In the first embodiment described above, the first scintillator 71 and first photodetector 73 that detect passing β rays, and the second scintillator 75 and second photodetector 77 that detect fluorescent X-rays were all disposed at the first opening 31a of the suction member 31. However, this is not limiting, and the detection unit 7'' of the third embodiment may be configured to detect fluorescent X-rays, i.e., the second scintillator 75' and second photodetector 77' may be disposed outside the suction member 31. Specifically, the second scintillator 75' and second photodetector 77' may be disposed at any position on a spherical surface having a predetermined radius from the position where the particulate matter FP is trapped on the collection filter 1. Note that it is preferable to dispose the second scintillator 75' and second photodetector 77' as close as possible to the position where the particulate matter FP is trapped on the collection filter 1 (i.e., it is preferable to make the predetermined radius small).

[0062] For example, as shown in Fig. 6, the second scintillator 75' and the second photodetector 77' can be disposed at a predetermined distance from the position where the particulate matter FP is trapped on the side of the collection filter 1 where the particulate matter FP is trapped. Alternatively, the second scintillator 75' and the second photodetector 77' can be disposed on the opposite side of the collection filter 1 from the side where the particulate matter FP is trapped. Fig. 6 is a diagram showing the configuration of the detection unit of the third embodiment.

[0063] When the particulate matter FP trapped on the collection filter 1 is irradiated with beta rays from the beta ray generating unit 5, fluorescent X-rays are emitted radially from the particulate matter FP trapped on the collection filter 1. Therefore, even if the second scintillator 75' and the second photodetector 77' are disposed at any position on a spherical surface having a predetermined radius from the position on the collection filter 1 where the particulate matter FP is trapped, fluorescent X-rays emitted from the particulate matter FP can be detected.

[0064] Furthermore, the detection unit 7'' having the above-described configuration can be realized by providing the above-described second scintillator 75' and second photodetector 77' to an existing analysis device in which a configuration for detecting passing beta rays (first scintillator 71 and first photodetector 73) is provided in the first opening 31a. In other words, the detection unit 7'' has a configuration that makes it easy to expand an existing analysis device.

[0065] 4. Features of the Embodiments The above-described first to third embodiments have the following features. (1) An analysis device (e.g., analysis device 100) includes a β-ray source (e.g., β-ray source 51), a detection unit (e.g., detection units 7, 7′, 7″), and an analysis unit (e.g., analysis unit 9). The β-ray source irradiates an object to be analyzed with β-rays. The detection unit simultaneously detects transmitted β-rays that have passed through the object to be analyzed and fluorescent X-rays generated by irradiating the object to the β-rays, and outputs a detection signal. The analysis unit obtains, from the detection signal, a first signal generated by detecting the transmitted β-rays and a second signal generated by detecting the fluorescent X-rays. Furthermore, the analysis unit calculates information regarding the mass concentration of the object to be analyzed based on the first signal, and calculates information regarding the elements contained in the object to be analyzed based on the second signal.

[0066] In the above analytical device, the detection unit simultaneously detects the transmitted beta rays and the fluorescent X-rays and outputs a detection signal. That is, the detection signal includes a first signal derived from the transmitted beta rays and a second signal derived from the fluorescent X-rays. The analysis unit also calculates information regarding the mass concentration of the analyte based on the first signal, and calculates information regarding the elements contained in the analyte based on the second signal.

[0067] In this way, the above-described analytical device can calculate information about the mass concentration of an object to be analyzed and information about elements contained in the object to be analyzed with a simple device configuration. Furthermore, because the detection unit can simultaneously detect transmitted beta rays and fluorescent X-rays, the analysis results of the object to be analyzed (information about the mass concentration and elements contained in the object to be analyzed) can be obtained in a short time.

[0068] (2) In the analyzing device of (1) above, the detection unit may have a first scintillator (e.g., first scintillator 71), a second scintillator (e.g., second scintillator 75, 75′), and a light detection unit. The first scintillator is disposed opposite the β-ray source and generates a first light when passing β rays are incident thereon. The second scintillator is disposed opposite the β-ray source and generates a second light when fluorescent X-rays are incident thereon. The light detection unit detects the first light and the second light and outputs a detection signal. This allows the passing β rays and fluorescent X-rays to be converted into the first light and the second light, respectively, and allows the passing β rays and fluorescent X-rays to be easily detected.

[0069] (3) In the analysis device of (2) above, the light detection unit may include a first light detector (e.g., first light detector 73) that detects the first light and outputs a first signal, and a second light detector (e.g., second light detectors 77, 77′) that detect the second light and output a second signal. This allows the first light and the second light to be simultaneously detected by separate light detectors. As a result, the first signal and the second signal can be acquired more simply without performing signal separation processing on the acquired signals.

[0070] (4) In the analysis device of (2) above, the light detection unit may have a third light detector (e.g., third light detector 81) that detects both the first light and the second light and outputs a detection signal. This allows the first light and the second light to be detected by a single light detector, thereby simplifying the device configuration.

[0071] (5) In the analysis device of (4), the analysis unit may separate the first signal and the second signal from the detection signal based on the pulse width of the detection signal. This allows the first signal and the second signal to be accurately separated using the pulse width of the detection signal.

[0072] (6) In the analysis device of (4), the analysis unit may separate the first signal and the second signal from the detection signal based on the peak intensity of the detection signal, thereby enabling accurate separation of the first signal and the second signal using the intensity of the detection signal.

[0073] (7) In the above-described analytical devices (1) to (6), the analysis target may be particulate matter (e.g., particulate matter FP). In this case, the analytical device may further include a collection device (e.g., collection device 3) that collects particulate matter in a collection filter (e.g., collection filter 1). The β-ray source and the detection unit may be provided in the collection device. This allows the mass concentration of the particulate matter and information about the elements contained in the particulate matter to be calculated in a short period of time. Furthermore, providing the β-ray source and the detection unit in the collection device allows the analytical device to be made compact.

[0074] (8) The analysis method includes the following steps: A step of irradiating an object to be analyzed with beta rays (e.g., step S2); A step of simultaneously detecting transmitted beta rays that have passed through the object to be analyzed and fluorescent X-rays generated by irradiating the object to be analyzed with beta rays, and outputting a detection signal (e.g., step S2); A step of acquiring, from the detection signal, a first signal generated by detecting the transmitted beta rays and a second signal generated by detecting the fluorescent X-rays (e.g., step S3); and A step of calculating information about the mass concentration of the object to be analyzed based on the first signal, and calculating information about the elements contained in the object to be analyzed based on the second signal (e.g., step S4).

[0075] In the above analytical method, transmitted beta rays and fluorescent X-rays generated by irradiating an analyte with beta rays are simultaneously detected, and a detection signal is output. That is, the detection signal includes a first signal derived from the transmitted beta rays and a second signal derived from the fluorescent X-rays. Furthermore, in the above analytical method, information regarding the mass concentration of the analyte is calculated based on the first signal, and information regarding the elements contained in the analyte is calculated based on the second signal.

[0076] In this way, in the above analysis method, transmitted beta rays and fluorescent X-rays are detected simultaneously, so that the analysis results of the analysis target (information on the mass concentration and elements contained in the analysis target) can be obtained in a short time.

[0077] 5. Other Embodiments Although several embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention. In particular, the several embodiments and modifications described in this specification can be arbitrarily combined as needed. (A) The processing order and / or processing contents of each step of the analysis operation described using FIG. 3 can be appropriately modified without departing from the spirit of the invention.

[0078] (B) Other devices may be controlled based on the analysis results of the analysis target output by the analysis unit 9 of the above-described analysis device 100. For example, if the analysis target is particulate matter FP generated in a waste incineration facility, the analysis result may be output as to whether or not the particulate matter FP contains harmful substances (elements), and when this analysis result is output, a predetermined device in the waste incineration facility may be operated.

[0079] (C) By combining the above-described analytical device 100 with another analytical device (for example, a gas analyzer), a system for performing a more detailed analysis of the subject of analysis can be constructed.

[0080] (D) A beta-ray source that generates beta rays and an X-ray source that generates X-rays or the like to generate fluorescent X-rays from the particulate matter FP may be provided separately. In this case, for example, the beta-ray source and the X-ray source can be arranged adjacent to each other at the second opening 33a. This allows the single detector 7 arranged at the first opening 31a to simultaneously detect beta rays and fluorescent X-rays. The X-ray source can also be arranged on the opposite side of the collection filter 1 from the side where the particulate matter FP is collected.

[0081] (E) The β-ray source 51 may be disposed at a position away from the second opening 33a. Specifically, the β-ray source 51 may be disposed at a position away from the second opening 33a and tilted with respect to the extension direction of the second opening 33a. In this case, the β-ray source 51 irradiates β-rays obliquely toward the second opening 33a. This prevents the β-ray source 51 from interfering with the flow of particulate matter FP through the second opening 33a. As a result, the particulate matter FP can be collected evenly and uniformly on the collection surface of the collection filter 1.

[0082] The present invention can be widely applied to fine particulate matter analyzers that analyze fine particulate matter suspended in a measurement space.

[0083] 100: Analysis device 1: Collection filter 11a: Take-up reel 11b: Delivery reel 3: Collection device 31: Suction member 31a: First opening 33: Discharge member 33a: Second opening 35: Suction pump 37: Collection member 5: β-ray generation unit 51: β-ray source 53: Restriction member 7, 7', 7'': Detection unit 71: First scintillator 73: First photodetector 75, 75': Second scintillator 77, 77': Second photodetector 79: Light-shielding member 81: Third photodetector 9: Analysis unit 91: Calculation unit 93: Display unit FP: Particulate matter

Claims

1. An analytical apparatus comprising: a beta-ray source that irradiates an object of analysis with beta rays; a detection unit that simultaneously detects transmitted beta rays that pass through the object of analysis and fluorescent X-rays generated by irradiating the object of analysis with the beta rays and outputs detection signals; and an analysis unit that acquires from the detection signals a first signal generated by detecting the transmitted beta rays and a second signal generated by detecting the fluorescent X-rays, calculates information regarding the mass concentration of the object of analysis based on the first signal, and calculates information regarding the elements contained in the object of analysis based on the second signal.

2. The analytical device described in claim 1, wherein the detection unit comprises: a first scintillator arranged opposite the beta ray source and generating a first light when the passing beta rays are incident thereon; a second scintillator arranged opposite the beta ray source and generating a second light when the fluorescent X-rays are incident thereon; and a light detection unit that detects the first light and the second light and outputs the detection signal.

3. The analytical device described in claim 2, wherein the light detection section has a first light detector that detects the first light and outputs the first signal, and a second light detector that detects the second light and outputs the second signal.

4. The analytical device according to claim 2, wherein the light detection section has a third light detector that detects both the first light and the second light and outputs the detection signal.

5. The analyzer according to claim 4, wherein the analysis section separates the first signal and the second signal from the detection signal based on a pulse width of the detection signal.

6. The analyzer according to claim 4, wherein the analysis section separates the first signal and the second signal from the detection signal based on peak intensity of the detection signal.

7. An analytical device according to any one of claims 1 to 6, wherein the subject of analysis is particulate matter, and further comprising a collection device that collects the particulate matter in a collection filter, and the beta radiation source and the detection unit are provided in the collection device.

8. An analytical method comprising the steps of: irradiating an object to be analyzed with beta rays; simultaneously detecting transmitted beta rays that have passed through the object to be analyzed and fluorescent X-rays generated by irradiating the object to be analyzed with the beta rays and outputting a detection signal; acquiring from the detection signal a first signal generated by detecting the transmitted beta rays and a second signal generated by detecting the fluorescent X-rays; and calculating information regarding the mass concentration of the object to be analyzed based on the first signal, and calculating information regarding the elements contained in the object to be analyzed based on the second signal.

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