JP2021004814A - Ion source abnormality detection device and mass spectroscope using the same - Google Patents

Abstract

To provide an ion source abnormality detection device which can automatically detect the spray abnormality in the ionization process of a mass spectroscope, and provide the mass spectroscope using the same.SOLUTION: There are provided: an ion source abnormality detection device for detecting the abnormality in an ion source of spraying a sample liquid containing an analysis object component into an ion source spray chamber by using spray means and ionizing the analysis object component; and a mass spectroscope using the same. The ion source abnormality detection device comprises: irradiation means which emits light into an ion source spray chamber; photographing means which photographs the inside of the ion source spray chamber; photographed image storage means which stores a photographed image including a spray tip portion of the spray means photographed by the photographing means; spray state determination condition setting means which previously sets and stores the setting value for the luminance gradation value of at least one or more determination pixels in the photographed image; and spray abnormality detection means which detects the abnormality in the spray state by using the stored luminance gradation value and setting value of the determination pixel in the photographed image.SELECTED DRAWING: Figure 1

Description

The present invention relates to a mass spectrometer for chemical analysis by spray-spraying a sample liquid in atmospheric pressure to form microcharged droplets and ionizing by heating vaporization, and an ion source thereof, and detects an abnormality in spraying the sample liquid. The present invention relates to an ion source abnormality detection device and a mass spectrometer using the same.

In a liquid chromatography mass spectrometer or the like, a liquid sample to be analyzed is subjected to mass spectrometry by forming charged microdroplets using an atmospheric pressure spray and heating and vaporizing the liquid sample to ionize the components contained in the liquid material. By introducing it into the device, chemical analysis is performed.

In this device, it is necessary to stably ionize a liquid sample, and for that purpose, it is important to form stable microdroplets with an atmospheric pressure spray. However, the atmospheric pressure spray process tends to be destabilized due to factors such as nozzle contamination, which affects the spray spray state and the state of the droplets formed. Therefore, it is important to stabilize the state of the atmospheric pressure spray process in the atmospheric pressure ionized mass spectrometer.

In the mass spectrometer, a solution that disperses and holds the sample to be analyzed at atmospheric pressure is ionized by spraying and charging, and introduced into the mass spectrometer by the force of an electric field to analyze the sample to be analyzed. This ionization process greatly affects the measurement accuracy of the mass spectrometer.

In a general mass spectrometer, a method called an electrospray method is used for atomization and ionization of a solution that disperses and holds a sample to be analyzed. In this method, a capillary that supplies the liquid is placed in a high-speed gas jet to atomize the liquid and spray it, or a high voltage is applied between the electrodes facing the capillary and the liquid is pulled out from the capillary by an electric field. A method such as spraying can be used. In either method, the sprayed droplets have a small diameter of several tens of μm or less, and are then rapidly vaporized by heating or the like to ionize the solvent to be analyzed dispersed in the liquid.

Since this ionization process greatly affects the measurement accuracy of the mass spectrometer, high stability is required. In a general mass spectrometer, a window is provided for observing the state of the spraying process, and the operator can observe the spraying state from the window. However, the diameter of the capillary that supplies the liquid is as small as about 100 μm, the amount of liquid sprayed is small, the diameter is extremely small as several tens of μm or less, and in addition, it disappears in a short time. Visual observation is extremely difficult, and there is a limit to visual abnormality judgment.

Some mass spectrometers have a camera installed in the atmospheric pressure spray section to make it easier to observe the spray state. In order to observe the state of the minute capillary tip and the droplets ejected from it, it is necessary to make magnified observations. However, considering the contamination of the camera lens due to the scattering of the liquid sprayed from the spray nozzle, it is difficult to measure the camera close to the measurement target, and the magnification is limited.

In relation to these, in Patent Document 1, a camera for observing the tip of the nozzle is installed, and the formation of droplets at the tip of the spray nozzle is detected and controlled by the gas spraying means to spray. A configuration for removing droplets at the tip of a nozzle is disclosed.

Further, in Patent Document 2, in the electrospray method in which a high voltage is applied to an electrode to form droplets, the state of the liquid at the tip of the electrode is observed by using a camera that observes the tip of the nozzle, and the electrode of the electrospray is used. Control the applied voltage.

JP-A-2007-127555 Patent No. 24080893

Patent Document 1 aims to keep the nozzle tip normal by preventing the formation of droplets on the tip of the spray nozzle. However, in this system, the camera detects relatively large droplets with a diameter of about 1 mm, and it is not possible to observe the spray state itself formed by droplets of several μm or less.

Further, in Patent Document 2, in order to observe the liquid state of the electrode tip described here, it is necessary to bring the camera considerably close to the nozzle tip, and from the viewpoint of contamination and the like, the actual observation device is always used. It seems difficult to install.

As described above, although the spray state in the ionization process of the mass spectrometer is an important process, it has a problem that it is difficult to observe and the occurrence of an abnormality cannot be detected.

From the above, it is an object of the present invention to provide, for example, an ion source abnormality detection device capable of automatically detecting a spray abnormality in the ionization process of a mass spectrometer, and a mass spectrometer using the ion source abnormality detection device.

The present invention is an ion source abnormality detecting device for spraying a sample liquid containing a component to be analyzed into an ion source spraying chamber by using a spraying means and detecting an abnormality of the ion source for ionizing the component to be analyzed. A mass spectrometer using the above, which includes an irradiation means for irradiating the inside of the ion source spray chamber with light, a photographing means for photographing the inside of the ion source spray chamber, and a spray tip portion of the spraying means photographed by the photographing means. In the captured image storage means for storing the captured image, the spray state determination condition setting means for presetting and storing the set values for the brightness gradation value of at least one or more determination pixels in the captured image, and the stored captured image. It is characterized by comprising a spray abnormality detecting means for detecting an abnormality in a spray state by using a brightness gradation value and a set value of a determination pixel.

According to the above configuration of the present invention, for example, an ion source abnormality detecting device capable of automatically detecting a spray abnormality in the ionization process of a mass spectrometer, and a mass spectrometer using the ion source abnormality detecting device can be provided.

The figure which shows the system whole system structure of the ion source anomaly detection means of this invention, and the mass spectrometer using it. The figure which showed the spray nozzle 1 of the ion source spray chamber 2 in an enlarged view. The figure which showed typically the image taken by the photographing means 4. A processing flow for determining a spray abnormality according to the present invention. The figure which showed typically the state of the photographed image when a spray abnormality occurred.

Hereinafter, an embodiment of the ion source abnormality detecting means of the present invention and a mass spectrometer using the same will be described with reference to the drawings.

First, the ion source abnormality detecting means and the overall configuration of the mass spectrometer using the means will be described.

FIG. 1 is a diagram showing the entire system configuration of the ion source abnormality detecting means of the present invention and the mass spectrometer using the means. The left side of the figure schematically shows the ion source 30 which is the target of abnormality detection, and the right side of the figure shows the spray state monitoring means 11 for detecting an abnormality and the overall control means 15 of the mass spectrometer. The ion source 30 is provided with an ion source spray chamber 2 and a spray nozzle 1 for supplying and spraying a sample solution. In the present invention, the lighting means 3 and the photographing means 4 are arranged in the ion source 30, and the spray state monitoring means 11 determines that the image processing is performed based on the limited image information obtained from the photographing means 4, and the ion source 30 is abnormal. Is detected.

Next, the structure and operation of the ion source 30 will be described. First, the ion formation process in the ion source 20 of the mass spectrometer will be briefly described.

FIG. 2 is an enlarged view of a spray nozzle 1 which is a spray means of the ion source spray chamber 2, and is for explaining a process of spraying a sample droplet into fine droplets and vaporizing and ionizing the sample droplets. It is a figure.

The spray nozzle 1 has a double pipe structure consisting of a sample liquid supply pipe 17 and a spray gas supply pipe 18. Since the sample liquid 19 supplied by the sample liquid supply pipe 17 is supplied into the high-speed gas jet supplied by the spray gas supply pipe 18, it is torn off by the force of the high-speed gas flow and is split and sprayed onto the droplets. Will be done. The sample liquid is a solution in which the sample components are dispersed in an alcohol-based solvent such as water or methanol. As the high-speed gas, air or nitrogen gas can be used.

Further, in the spraying process of the ion source 30, an electric charge is applied to the divided sprayed droplets by applying a voltage to the spray nozzle 1. After that, by vaporizing the solvent component of the formed charged droplet, the charge density of the droplet increases, a phenomenon called Coulomb explosion occurs, and the droplet repeats explosive splitting. Finally, ions of the sample component alone are generated. The generated ion of the sample component is taken into the mass spectrometer by electrostatic force to identify the component.

In the above ionization process, the smaller the initial droplet diameter formed by spraying from the sample solution, the more efficiently the solvent can be vaporized in a shorter time, and ions can be generated. Therefore, the initial droplet diameter generated by spraying with the ion source 30 is required to be smaller. The particle size of the droplets produced by the spray nozzle 1 decreases as the flow velocity of the high-speed gas used for spraying increases. By setting the flow velocity of the high-speed gas from 100 m / s to several hundred m / s, which is close to the speed of sound, droplets of several μm to several tens of μm can be formed.

In order to vaporize the solvent more efficiently in a short time, the spray liquid is configured to blow a high-temperature heating gas 21 at several hundred degrees Celsius. Although the high temperature gas spray nozzle is not shown in FIGS. 1 and 2, the heating gas 21 is vaporized as a solvent of the droplets by spraying the heating gas 21 onto the liquid immediately after spraying as shown by the thick arrow in FIG. To promote.

The ionization process using the sample solvent 19, the high-speed gas stream 20, and the high-temperature heating gas stream 21 is performed in the ion source spray chamber 2 in order to ensure contamination and safety to the surroundings. In the ion source spray chamber 2 of this embodiment, a cylindrical aluminum chamber having a diameter of about 10 cm and a thickness of about 5 cm is used in consideration of the flow of the spray gas.

Next, the configuration of the observation unit for observing the spray state of the ion source 30 will be described. In the configuration of this embodiment, the lighting means 3 and the photographing means 4 are arranged in order to observe the sprayed state of the sample solution. The lighting means 3 and the photographing means 4 such as a camera are used for lighting means in the ion source spray chamber 2 as shown in FIG. 1 in consideration of the influence on the spray process such as the spray gas flow and the heating gas flow and the contamination. A window 5 and a window 6 for photographing means are provided. Glass was arranged in these windows 5 and 6, and the lighting means 3 and the photographing means 4 were arranged outside the ion source spray chamber 2.

Due to these restrictions, it is not possible to bring the photographing means 4 such as a camera close to the vicinity of the spray tip of the spray nozzle 1, and there are also restrictions on the lens diameter and the like, so that it is difficult to perform imaging at high magnification. Further, as described above, the droplets sprayed from the spray nozzle are very small, about several μm to several tens of μm, and the flight speed reaches from 100 m / s, which is the spray gas speed, to nearly several hundred m / s. Further, the droplet immediately after spraying is rapidly vaporized by a heating gas or the like, and the diameter of the droplet, which was about several μm to several tens of μm immediately after spraying, rapidly decreases. For these reasons, it is not possible to directly observe the spray droplets ejected from the spray nozzle.

Therefore, in this embodiment, the lighting means 3 arranged outside the ion source spray chamber 2 is configured to irradiate the vicinity of the tip of the spray nozzle 1 with light. Then, the photographing means 4 arranged outside the ion source spray chamber 2 is configured so that the vicinity of the spray nozzle can be observed.

When the vicinity of the spray nozzle during spraying is photographed in this way, as shown in FIG. 2, the light scattered by the spray droplets can be observed in the region 22 immediately below the spray nozzle 1. However, as described above, since the spray droplets vaporize rapidly, the scattering term due to the spray droplets could not be observed in the spray region 23 slightly below the spray nozzle. This is because the droplet diameter is so small that the illumination light cannot be scattered. The present invention proposes a method for detecting a spray abnormality based on the imaging information of the scattered light directly under the spray nozzle by the illumination light.

Next, a method of detecting a spray abnormality will be described using a captured image of scattered light directly under the spray nozzle.

FIG. 3 is a diagram schematically showing an image taken by the photographing means 4 of this embodiment, and shows each pixel in the vicinity immediately below the spray nozzle.

According to the photographed image illustrated in FIG. 3, it can be seen that the portion where the illumination light is reflected emits white light and the other portion does not emit light at all. The parts that emit white light due to reflection are spray droplets having a diameter above a certain level and the tip of the spray nozzle.

In FIG. 3, the light emitting region on the left side of the portion indicated by 31 (white portion as compared with the background pixel) is the reflected light at the tip of the spray nozzle, and the light emitting region on the left side of the portion indicated by 32 is immediately after spraying. It is scattered light by droplets. Even in the spray image of the nozzle tip of the actual ion source, an image that emits light in a local limited region as shown in FIG. 3 can be observed. By preventing the reflected light of the irradiation light from entering the background in this way, it is possible to detect the scattered light from the nozzle tip and the spray droplets immediately below it with extremely high contrast as shown in FIG. ..

In the method for detecting a spray abnormality in this embodiment, in the captured image of FIG. 3, the pixel region that stably becomes a non-light emitting pixel in a normal spray state is defined as a non-light emitting detection region 35. A pixel region that stably becomes a light emitting pixel is used as a light emitting detection region 34 and as a determination pixel. Then, in the sprayed state, whether or not the determination pixel in the non-emission detection area 35 is equal to or less than the predetermined brightness and whether or not the determination pixel in the light emission detection area 34 is equal to or more than the predetermined brightness indicates whether or not the spray is normal. It makes a judgment.

FIG. 4 is a processing flow for determining a spray abnormality according to the present invention. This process should be performed by a computer. In the first processing step S1 of FIG. 4, irradiation is performed by the lighting means 3, and imaging is performed by the photographing means 4 in the ion source spray chamber 2 including the spray nozzle 1.

In the processing step S2, the pixel information of the light emission detection area 34 and the pixel information of the non-light emission detection area 35 are obtained from the obtained captured image. In this case, the brightness of each pixel is expressed by, for example, 256 gradations. When the tone is high, it indicates that there is light emission, and when the tone is low, it indicates that there is no light emission. It is assumed that the light emitting detection area 34 and the non-light emitting detection area 35 are determined by prior examination, and the pixels to be the determination pixels are determined in advance for each area. The number of determination pixels may be plural.

In the process step S3, it is determined whether or not the pixel information in the light emission detection region 34 has a predetermined brightness or higher. Here, it is confirmed that the specified brightness is, for example, 200 tones or more out of 256 tones, and if it is 200 tones or more, it is determined to be normal in the processing step S5. Further, when the tone is 200 tones or less, it is determined as abnormal in the processing step S5 because the light emission is insufficient. Here, it is advisable to also present the possible reasons for the abnormality.

In the processing step S4, it is determined whether or not the pixel information in the non-emission detection region 35 has a predetermined brightness or less. Here, it is confirmed that the specified brightness is, for example, 50 tones or less out of 256 tones, and if it is 50 tones or less, it is determined to be normal in the processing step S5. Further, when the tone is 50 or more, it is determined as abnormal in the processing step S7 because the light emission is excessive. Here, as a possible reason for the abnormality, it is preferable to also present the state of an abnormal event such that the issuing frame is not formed in a normal shape but is formed abnormally long or diagonally.

By using such a determination method, it is possible to detect a change in the spray state from the change in the non-light emitting region and the light emitting region even from the limited observation image in the ion source 30 of the mass spectrometer. For example, as the droplet diameter of the initial droplet of the sprayed liquid increases, the light emitting region expands and the brightness of the pixels in the non-light emitting region increases. Further, when the droplet diameter of the initial droplet becomes small or the spraying is stopped, the brightness of the light emitting region decreases. From such a change, it becomes possible to detect the state of the initial droplet ejected from the spray nozzle. It is presumed that the change in the droplet diameter is caused by factors such as fluctuations in the flow rate of the supplied sample liquid, fluctuations in the ejection speed of the spray gas, and fluctuations in the temperature of the heating gas. In addition, when foreign matter adheres to the tip of the spray nozzle, it is detected as an abnormality such as the light emitting region due to the spray droplets moving to the left or right.

FIG. 5 schematically shows the state of the captured image when a spray abnormality occurs. The left side of FIG. 5 is a diagram schematically showing the state of the captured image when the diameter of the sprayed droplets increases, and the center of FIG. 5 is a diagram schematically showing the state where the spraying direction is bent to the left side. The right side of FIG. 5 is a diagram schematically showing a state in which spraying is stopped and scattering by droplets is eliminated.

Next, the abnormality detection processing process will be described.

The abnormality detection processing process configuration in the spray state monitoring means 11 shown on the right side of FIG. 1 will be described. First, from the overall control means 15 of the mass spectrometer, abnormality determination pixel information and abnormality determination conditions for determining the spray state when a predetermined sample solution is sprayed under predetermined appropriate conditions are set in advance. The abnormality determination pixel information corresponds to the determination pixels in FIG. 3, and the abnormality determination condition is the luminance information defined as the luminance of the determination pixels in the light emission detection area 34 and the non-light emission detection area 35. These abnormality determination pixel information and abnormality determination conditions are stored in advance in the abnormality determination pixels and abnormality determination condition storage means 12 of the spray state monitoring means 11.

The mass spectrometer control means 15 transmits a spray observation signal 26 for confirming the spray state to the spray state monitoring means 11 after starting the spray operation by the spray control means 16 for moving the ion source 30. The spray observation signal 26 is configured so that the spray state monitoring means 11 confirms the spray state, and if there is an abnormality, the abnormality detection signal 13 is transmitted to the mass spectrometer control means 15.

In the ion source 30 of the present invention, the lighting means 3 and the photographing means 4 are arranged outside the ion source spraying chamber 2 in order to avoid the influence on the ionization process. The spray state monitoring means 11 includes lighting for controlling the lighting means 3 and the photographing means 4, and a camera controlling means 7, and after receiving the spray observation signal 26 from the mass spectrometer, photographs the spray image. After the captured image information is temporarily stored by the image storage means 8, the spray pixel and the brightness information extraction means 9 store a pixel image (FIGS. 3 and 4) in the vicinity of the spray nozzle for determining a spray abnormality and its brightness information. Extract. Then, the information extracted from the captured image and the information stored in the preset abnormality determination pixels and the abnormality determination condition storage means 12 are compared and determined by the comparison means and the abnormality determination means 10, and if it is determined to be abnormal, it is determined. The abnormality detection signal 13 is transmitted to the mass spectrometer control means 15. The mass spectrometer control means 15 controls the operation of the device when an abnormality is detected, such as stopping the device.

Next, a method of lighting by the lighting means 3 provided on the outside of the ion source spray chamber 2 will be described.

In the abnormality detection device of the present invention, the clearer the contrast between the background of the image to be captured and the reflected light by the spray droplets, that is, the difference in brightness, the easier it is to determine the abnormality in the spray state. Therefore, it is important to eliminate the entry of the illumination light into the background portion. The entry of illumination light into the background is reflected by the inner wall surface of the spray chamber. In this embodiment, in order to prevent the illumination light of the lighting means 3 from being reflected by the inner wall of the ion source spray chamber 2 and shining, the inner wall of the ion source spray chamber 2 is roughened and colored black. As the coloring treatment, heat resistant coating, alumite treatment and the like can be used.

In the spray chamber 2 of this embodiment, a treatment that combines an alumite treatment and a heat-resistant coating is performed. As shown in FIGS. 3 and 5, a part of the vicinity of the tip of the spray nozzle is also captured in the captured image. Although not carried out in this example, it is considered that an image that is easier to judge can be obtained by the reflection suppression treatment near the tip of the spray nozzle.

As another method of suppressing the reflected light, a method of arranging and designing the light after irradiating the spray droplets or the reflected light to the exhaust duct side can be considered. Since this method affects the installation position and inner surface shape of the irradiation means 3 in the spray chamber 2, it is difficult to design the arrangement of the spray chamber 2 and various internal parts.

Further, in order to suppress the entry of the illumination light into the background portion, the angular relationship between the irradiation direction of the light by the irradiation means 3 and the photographing means 4 is also important. If the lighting means 3 is arranged at a position facing the photographing means 4, the background becomes bright and should be avoided. Further, it is better to avoid the arrangement of the illumination in the coaxial direction with the photographing means because the influence of the wall reflection of the spray chamber 2 is large. It is necessary to provide an angle between the lighting means and the photographing means and to select a place where the reflected light affects the photographed image. In the preliminary examination, when the angle between the optical axis of the photographing means and the lighting means was around 30 to 60 degrees, the intrusion of reflected light could be suppressed. In this embodiment, the lighting means is arranged on the opposite side of the photographing means, at an angle of about 45 degrees.

Next, a method of photographing by the photographing means 4 provided outside the ion source spraying chamber 2 will be described.

As the photographing direction of the photographing means 4, in this embodiment shown in FIG. 1, it is arranged on the cylindrical side surface of the cylindrical ion source spray chamber 2. In the figure of the ion source spray chamber of FIG. 1, the introduction port to the mass spectrometer is not shown, but the introduction port to the mass spectrometer is located on the back side of the paper surface near the center of the cylinder of the cylindrical ion source spray chamber 2. Have been placed. Since the photographing means 4 is arranged on the side surface of the cylinder, it is easy to detect the spray bending on the side toward the introduction port to the mass spectrometer, that is, the direction perpendicular to the paper surface, but the bending in the direction parallel to the paper surface is detected. Difficult to do.

In this embodiment, the photographing means 4 is arranged on the side surface of the cylinder because it seems that the spraying on the side toward the introduction port to the mass spectrometer has a greater influence on the measurement result. However, it goes without saying that it is desirable to arrange the photographing means in a plurality of directions in order to detect the bending in the spraying direction. In this case, it is necessary to arrange the illumination means 3 at an angle at which the irradiation light of the illumination means 3 does not affect the image of any of the imaging means. Further, as a method of observing the spray bending in all directions with one photographing means, a method of arranging the camera directly under the spray nozzle is conceivable, but it is essential to take measures against stains on the photographing means 3 by the sprayed liquid. It seems that

Next, the processing at the time of abnormality detection will be described.

As processing after the spray state monitoring means 11 detects the abnormal spray and transmits the abnormality detection signal 13, a method of stopping the device or a method of issuing a caution alarm can be taken.

Further, if a means for analyzing the detected image at the time of detecting the abnormal spray of the present invention is also provided, it is possible to know the state of the abnormal spray as described with reference to FIG. For example, in the abnormality detection image on the left of FIG. 5, it is predicted that the spray droplet diameter is large or the spray liquid amount is increasing as the cause. Therefore, at least one of the ion source parameters for spraying and ionizing the liquid sample, such as the spray gas pressure, the sample liquid flow rate, the nozzle application voltage, and the spray gas temperature, is variably adjusted so that the spray state becomes appropriate. It can also be used for feedback control.

Further, when the bending in the spraying direction is detected as shown in the center of FIG. 5, it is predicted that the tip of the spray nozzle is clogged or contaminated as the cause. In this case, it may be recovered by performing a process of cleaning the tip of the nozzle. Therefore, the mass spectrometer is provided with a spray nozzle cleaning process for clearing or cleaning the spray nozzle, and the mass spectrometry is interrupted and the existing spray nozzle cleaning process is operated depending on the determination result of the already sprayed abnormality detecting means. It is also possible to have the mass spectrometer automatically recover by performing the above processing.

In order to detect an abnormality in which light emission is detected in the non-light emission detection region in this way, the positions of the determination pixels are the position directly below the tip portion of the spray nozzle and both sides away from the tip portion of the spray nozzle. It should be set to the position. This makes it possible to detect the extension of the luminescent flame, the fluctuation of the luminescent flame, and the like.

By utilizing the detection result of the abnormality detection method of the present invention and incorporating the above-mentioned abnormality recovery process into the mass spectrometer, it is possible to provide a mass spectrometer having high reliability and stability.

Next, pollution control treatment will be described.

In order to detect the spray abnormality of the present invention more stably, it is effective to take measures against contamination by the spray sample in the ion source spray chamber. As described above, the spray abnormality detection in the present invention focuses on a pixel that irradiates light directly under the spray nozzle and has a characteristic brightness state of the shape of the scattered light by the initial spray droplet having a relatively large droplet diameter. It is judged by.

In this method, the scattering state of the irradiation light by the irradiation means 3 may change due to the dirt caused by the spray liquid or the like adhering to the inside of the ion source spray chamber 2, which may affect the determination pixels. In particular, when the camera protection window 6 on the photographing means 4 side is contaminated with the sprayed sample droplet liquid or the like, there is a concern that the determination pixels may be affected.

An embodiment for a method for ensuring robustness against dirt in the ion source spray chamber 2 will be described. For this purpose, for example, in order to prevent a detection error due to dirt, the illumination means 3 irradiates the illumination light without spraying, and the photographing means 4 acquires an image. Then, when an abnormal brightness value is detected in the abnormality determination pixel in the captured image, the determination pixel is stored as an abnormality pixel. In this way, abnormal pixels can be extracted by acquiring an image without performing the spraying operation and performing an abnormality determination. Then, in the abnormality determination process at the time of spraying from the actual spray nozzle, if the determination pixel excluding the abnormality pixel is used to determine the abnormality spray, the influence of dirt or the like can be prevented. However, as the number of abnormal pixels increases, the accuracy of determining abnormal spraying also decreases. Therefore, when the number of abnormal pixels generated exceeds the predetermined number, it is necessary to take measures such as cleaning the inside of the spray chamber. When the number of abnormal pixels generated exceeds the predetermined number, the spray chamber cleaning required is notified.

The determination excluding the abnormal pixels is effective as a pollution countermeasure, but when the number of abnormal pixels increases, the number of determination pixels decreases, and there arises a problem that the determination of spray abnormality cannot be performed. Therefore, the following embodiment can be considered as a method of determining a spray abnormality without reducing the number of determination pixels by using the contaminated determination pixels. In the same manner as described above, the illumination light is irradiated by the illumination means without spraying, and the image is acquired by the photographing means. Then, the brightness information of the determination pixel when the spray is stopped is stored. Then, in the abnormality reflection processing at the time of spraying from the actual spray nozzle, the difference processing with the luminance information in the state where the spray is not performed is performed, and the image after the difference processing is used as the determination image. By performing such processing, it is possible to perform abnormality determination by removing the deviation in brightness due to contamination of the determination pixels to some extent. However, it goes without saying that even with this method, it becomes difficult to accurately detect anomalies due to contamination.

Next, the correspondence to various spray conditions will be described.

The conditions for spraying the sample solution by the spray nozzle may vary depending on the type and concentration of the sample to be measured and the type of solvent. As a result, the diameter and amount of the initial droplets sprayed from the spray nozzle, the time until vaporization, and the like may be affected. In this case, it also affects the condition of the image taken by the shooting method of the present invention. Therefore, it is necessary to change the pixel for discriminating the spray abnormality and the brightness threshold condition for discriminating according to the spraying condition and the measurement sample condition.

Therefore, in the ion source abnormality detecting means of this embodiment and the mass spectrometer using the same, a plurality of spray state determination conditions can be stored, and the sample or sample solvent condition to be measured, the spray gas pressure, and the sample liquid flow rate can be stored. Provide a spray state determination condition switching means for switching two or more spray state determination conditions according to at least one or more ion source parameter conditions for spraying and ionizing a liquid sample such as nozzle applied voltage and spray gas temperature. Therefore, it is possible to discriminate the spray abnormality with higher accuracy.

The ion source anomaly detection device of the present invention and the mass spectrometer using the ion source abnormality detector described above can accurately detect an abnormality in the spray state of the sample solution of the ion source, and can be used for high stability and high reliability. A mass spectrometer can be provided.

In order to make the description of the present invention easy to understand, the spray nozzle is based on the image of an air nozzle or an electrospray currently widely used as the droplet forming means of the present invention. However, the abnormality detection method of the present invention is other than the spray nozzle. Needless to say, it is widely applicable to various spraying means for forming fine droplets.

More specifically, according to the present invention, since the light irradiation means and the photographing means used for detecting the spray abnormality are arranged outside the ion source chamber, the light irradiation means and the photographing means are not contaminated by the spray liquid. In addition, the light irradiation means and the photographing means do not affect the liquid formation state of the sample sprayed from the spray nozzle. Images taken by an imaging means arranged outside the ion source chamber cannot be individually identified because the magnification cannot be increased sufficiently. However, according to the above configuration, the spray state can be identified from the low-magnification already-sprayed image by extracting information such as the brightness difference between the scattered light generation region due to the spray gas at the tip of the nozzle and the periphery. Further, according to the above configuration, since the detection is performed by comparing the determination threshold luminance information of the preset determination pixel and the already determined pixel, high-speed and stable abnormality detection becomes possible even from a low-resolution captured image. .. Then, by constructing the control of the mass spectrometer according to the determination information by the above configuration, it is possible to provide the mass spectrometer capable of stably maintaining the appropriate ionization conditions.

1: Spray nozzle 2: Ion source spray chamber 3: Lighting means 4: Imaging means 5: Lighting protection window 6: Camera protection window 7: Lighting and camera control means 8: Image storage means 9: Spray pixel and brightness information extraction means 10 : Comparison means and abnormality determination means 11: Spray state monitoring means 12: Abnormality determination pixel and abnormality determination condition storage means 13: Abnormality detection information 14: Abnormality determination condition information 15: Mass analyzer control means 16: Spray control means 17: Sample Solution supply pipe 18: Spray gas supply pipe 19: Sample solution 20: Spray gas flow 21: Heating gas flow 22: Spray region (scattering region)
23: Spray area (non-scattering area)
34: Judgment pixel (light emission detection area)
35: Judgment pixel (non-emission detection area)
26: Spray observation signal

Claims (13)

An ion source abnormality detection device that sprays a sample liquid containing a component to be analyzed into an ion source spray chamber using a spraying means and detects an abnormality in the ion source that ionizes the component to be analyzed.
An imaging means for irradiating the inside of the ion source spraying chamber with light, a photographing means for photographing the inside of the ion source spraying chamber, and an imaging image for storing a photographed image including a spray tip portion of the spraying means photographed by the photographing means. The image storage means, the spray state determination condition setting means for presetting and storing the set values for the brightness gradation values of at least one or more determination pixels in the captured image, and the brightness of the determination pixels in the stored captured image. An ion source abnormality detecting device comprising a spray abnormality detecting means for detecting an abnormality in a spray state using a gradation value and the set value. The ion source abnormality detection device according to claim 1.
The spray abnormality detecting means has a light emission detection region and a non-light emission detection region set in advance for the captured image including the spray tip portion of the spray means, and the brightness gradation of the determination pixel set in the light emission detection region. An ion source abnormality is characterized in that an abnormality in a spray state is detected when the value is lower than the set value or the brightness gradation value of the determination pixel set in the non-emission detection region is higher than the set value. Detection device. The ion source abnormality detection device according to claim 2.
The light emission detection region is set near the spray tip portion of the spray means, and the non-light emission detection region is set at a position away from the spray tip portion of the spray means. apparatus. The ion source abnormality detection device according to claim 3.
The positions of the determination pixels set in the non-emission detection region are set at positions directly below the spray tip portion of the spray means and positions on both sides away from the spray tip portion of the spray means. An ion source anomaly detection device characterized by this. The ion source anomaly detection device according to any one of claims 1 to 4.
The spraying means for spraying the sample liquid containing the component to be analyzed is composed of a sample supply thin tube for supplying the sample liquid and a high-speed gas jet supply means for supplying a high-speed gas jet to the tip of the sample supply thin tube. A characteristic ion source abnormality detection device. The ion source anomaly detection device according to any one of claims 1 to 5.
The ion source spray chamber is an ion source abnormality detection device characterized in that the inner surface thereof and the entire surface or a part of the equipment installed inside the ion source spray chamber are colored or surface-treated to suppress reflection of irradiation light. .. The ion source anomaly detection device according to any one of claims 1 to 6.
An ion source abnormality detection device, characterized in that a spray abnormality generation signal is generated when the spray abnormality detecting means determines an abnormality. The ion source abnormality detection device according to any one of claims 1 to 7.
At least one or more ion source parameters for spraying and ionizing a liquid sample such as spray gas pressure, sample liquid flow rate, nozzle application voltage, and spray gas temperature are variably adjusted according to the determination result of the spray abnormality detecting means. An ion source abnormality detection device including a spray condition control means. The ion source anomaly detection device according to any one of claims 1 to 8.
According to the determination result of the spray abnormality detecting means, the spraying means cleaning process for eliminating or cleaning the clogging of the spraying means is provided, and the mass spectrometry is interrupted according to the determination result of the spray abnormality detecting means, and the spraying is performed. Means An ion source anomaly detection device characterized by operating a cleaning process. The ion source anomaly detection device according to any one of claims 1 to 9.
A defect pixel detecting means for determining a non-spraying defective pixel by acquiring an image in a state where spraying by the spraying means is stopped and determining whether or not the determination pixel in the acquired image when spraying is stopped is in an abnormal range. An ion source abnormality detecting device comprising, removing defective pixels detected by the defective pixel detecting means from determination pixels for detecting abnormality at the time of spraying, and performing determination processing of spray abnormality. The ion source anomaly detection device according to any one of claims 1 to 10.
It has a difference processing means for acquiring and storing an image at the time of spray stop and performing difference processing from the brightness information of the photographed image at the time of spraying to the brightness information of the photographed image at the time of spray stop. An ion source abnormality detection device characterized in that it is used as an abnormality determination image by a detection means. The ion source abnormality detection device according to any one of claims 1 to 11.
At least two or more spray state determination conditions can be memorized, and a sample or sample solvent condition to be measured, or a liquid sample such as spray gas pressure, sample liquid flow rate, nozzle application voltage, spray gas temperature, etc. is sprayed and ionized. An ion source abnormality detecting apparatus comprising: a spray state determination condition switching means for switching the two or more spray state determination conditions according to at least one or more of the ion source parameter conditions for the purpose. A mass spectrometer comprising the ion source anomaly detection device according to any one of claims 1 to 12.

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