Hydrogen flame ionization detector and gas chromatograph
A cylindrical collector with a thinner region and insulating support material in FIDs addresses heat-induced noise issues, enhancing measurement accuracy by reducing thermal fluctuations and signal noise.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SHIMADZU CORP
- Filing Date
- 2025-11-26
- Publication Date
- 2026-07-23
AI Technical Summary
In existing hydrogen flame ionization detectors (FIDs), the collector is heated by the hydrogen flame, causing fluctuations in the wire resistance and noise in the ion detection signal due to heat transmission.
A cylindrical collector design with a thinner region between the first and second positions, coupled with an insulating support material, reduces heat transfer and maintains lower temperatures, thereby suppressing noise in the ion detection signal.
The design effectively reduces noise in the ion detection signal, improving the measurement accuracy of the gas chromatograph by preventing temperature fluctuations in the collector and connected components.
Smart Images
Figure JP2025041178_23072026_PF_FP_ABST
Abstract
Description
Hydrogen flame ionization detector, gas chromatograph
[0007] ,
[0006] , ,
[0001] The present disclosure relates to a hydrogen flame ionization detector and a gas chromatograph.
[0002] In the field of gas chromatography, a gas chromatograph using a hydrogen flame ionization detector (FID: Flame Ionization Detector) capable of detecting most organic compounds is most commonly used.
[0003] Japanese Unexamined Patent Application Publication No. 2010-2420 (Patent Document 1) discloses the basic configuration of an FID. In an FID, ions generated by ionizing a sample using a hydrogen flame are collected by a collector. Then, a current signal generated by the collection of ions by the collector is detected by a processing device via a wire connected to the collector.
[0004] Japanese Unexamined Patent Application Publication No. 2010-2420
[0005] In an FID, there was a problem that when the collector was heated by a hydrogen flame generated from a nozzle and the heat was transmitted to the wire through the collector, the resistance of the wire fluctuated and noise occurred in the ion detection signal. [[ID=A first aspect of the present invention is a flame ionization detector comprising: a nozzle for generating a hydrogen flame; a collector positioned at a distance from the nozzle in its extension direction for collecting ions generated by ionizing a sample with the hydrogen flame; a cylindrical body extending in the extension direction, housing the nozzle and collector in its internal space; and an insulating support material that physically connects the inner wall of the body and the outer wall of the collector. The body supports the support material and the nozzle at positions separated in the extension direction. The collector is connected to a wire that transmits a signal of the current generated by the collection of ions to a processing device. The collector is cylindrical in shape. A first position, which is the end face of the collector proximal to the nozzle, and a second position, which is the position of the collector connected to the wire, are separated in the extension direction. In the collector, the thickness of at least a portion of the region between the first position and the second position is thinner than the thickness of the first position.
[0008] A second aspect of the present invention is a flame ionization detector comprising: a nozzle for generating a hydrogen flame; a collector positioned at a distance from the nozzle in its extension direction for collecting ions generated by ionizing a sample with the hydrogen flame; a cylindrical body extending in the extension direction, housing the nozzle and collector in its internal space; and an insulating support material that physically connects the inner wall of the body and the outer wall of the collector. The body supports the support material and the nozzle at positions separated in the extension direction. The collector is connected to a wire that transmits a signal of the current generated by the collection of ions to a processing device. The collector is cylindrical in shape. At least a portion of the outer wall of the collector is blackened.
[0009] According to this disclosure, noise in the ion detection signal can be reduced in the FID.
[0010] This is a schematic diagram of a gas chromatograph according to an embodiment. This is a schematic diagram of an FID according to a comparative example. This is a schematic diagram of an FID according to modified example 1. This is a schematic diagram of an FID according to modified example 2. This is a schematic diagram of an FID according to modified example 3. This is a schematic diagram of an FID according to modified example 4. This is a schematic diagram of an FID according to modified example 5. This is a schematic diagram of an FID according to modified example 6. This is a schematic diagram of an FID according to modified example 7.
[0011] Embodiments of the present invention will be described in detail below with reference to the drawings. Note that identical or corresponding parts in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated.
[0012] [Configuration of the gas chromatograph according to the embodiment] Figure 1 is a schematic diagram of the gas chromatograph 100 according to the embodiment. Referring to Figure 1, the gas chromatograph 100 includes an FID 10A, a wire 91, a column 97, a sample injection device 98, and a controller 99.
[0013] The sample injection device 98 is a device into which the sample is injected. Specifically, a carrier gas flows through the sample injection device 98, and the sample is injected into this carrier gas.
[0014] Column 97 separates the sample injected in the sample injection device 98 into its individual components. FID 10A detects the component-separated sample delivered from column 97.
[0015] The FID 10A includes a nozzle 4, a collector 1A, a body 2, and a support member 3. In this specification, the extension direction of the cylindrical collector 1A is the X-axis direction. In one embodiment, the FID 10A is installed with the end face 110 proximal to the nozzle 4 of the collector 1A facing downwards and the opposite end face 119 facing upwards, so that the extension direction (X-axis direction) of the collector 1A is approximately parallel to the direction of gravity. In this specification, the position of the end face 110 is also referred to as the "first position 110".
[0016] The nozzle 4 generates a hydrogen flame (shown as Figure 8 in Figure 1). In one embodiment, the hydrogen flame generated from the nozzle 4 rises in the X-axis direction. In one embodiment, the nozzle 4 and the body 2 are formed as independent components. In another embodiment, the nozzle 4 and the body 2 are formed as a single unit.
[0017] Collector 1A is a cylindrical electrode that collects ions generated by ionizing a sample with a hydrogen flame. Collector 1A is positioned at a distance from nozzle 4 in the extension direction of collector 1A itself (X-axis direction). Collector 1A is connected to electric wire 91. In this specification, the position of collector 1A connected to electric wire is also referred to as "second position 120". First position 110 and second position 120 are spaced apart in the X-axis direction. Collector 1A is typically made of metal.
[0018] Body 2 is a cylindrical member extending in the X-axis direction. Body 2 houses the nozzle 4 and collector 1A in its internal space 29. Body 2 supports the support member 3 and the nozzle 4 at positions spaced apart in the X-axis direction. The end face of body 2 on the side into which the sample flows (lower side) is referred to as end face 25, and the end face on the opposite side of body 2 (upper side) is referred to as end face 26. Body 2 is typically made of metal.
[0019] The support member 3 physically connects the inner wall 271 of the body 2 to the outer wall 172A of the collector 1A. Typically, the support member 3 is stably supported by the inner wall 271 of the body 2 and stably supports the collector 1A. In this specification, the inner wall and outer wall of a cylindrical member refer to the inner surface and outer surface of the cylindrical member, respectively. Note that the inner wall and outer wall do not necessarily have to be smooth curved surfaces and may have protrusions and indentations. In the example of Figure 1, the support member 3 includes a first support member 31 and a second support member 32, with the protrusions of the outer wall 172A of the collector 1A fitted between the first support member 31 and the second support member 32. The support member 3 is an insulator that insulates the collector 1A from the body 2 and maintains the voltage difference between the collector 1A and the body 2. The insulator is, in one example, a ceramic or a high-temperature resistant resin, and in a more specific example, alumina or Teflon®.
[0020] Body 2 has a first channel 21 through which the sample flows in from column 97, a second channel 22 through which hydrogen gas, which is the fuel gas, flows in, and a third channel 23 through which air, which is the auxiliary combustion gas, flows in. The first channel 21 merges with the second channel 22 and is then connected to the nozzle 4. The nozzle of the third channel 23 is located near the nozzle 4. As a result, the sample is burned by a hydrogen flame at the nozzle 4, and ions derived from the sample are generated.
[0021] An opening 28 is formed in the upper part of body 2. Water vapor generated by the combustion of the hydrogen flame is released to the outside through the opening 28.
[0022] The wire 91 transmits a signal of the current generated by the collection of ions to the controller 99.
[0023] In one embodiment, the controller 99 is a computer including a processor such as a CPU and memory. The controller 99 controls each part of the gas chromatograph 100 and processes the ion detection signal sent from the FID 10A. The controller 99 corresponds to one embodiment of the "processing apparatus".
[0024] [Structure of the collector according to the embodiment, and comparison with a comparative example] In the collector 1A according to the embodiment, the thickness of at least a portion of the region 130A between the first position 110 and the second position 120 is thinner than the thickness of the first position 110. With this configuration, the cross-sectional area of region 130A on a plane perpendicular to the X-axis direction is smaller than the area of the end face 110 (first position 110), so the thermal resistance of region 130A increases.
[0025] Figure 2 is a schematic diagram of the FID 10Z according to the comparative example. In the collector 1Z according to the comparative example, the area between the first position 110 and the second position 120 is not thinner than the thickness of the first position 110, and the cross-sectional area of the plane perpendicular to the X-axis direction between the first position 110 and the second position 120 of the collector 1Z is the same as the area of the end face 110 (first position 110).
[0026] Therefore, the thermal resistance of region 130A of collector 1A is greater than the thermal resistance of the corresponding portion of collector 1Z.
[0027] Therefore, even if the collector 1A reaches a high temperature at the first position 110 due to contact with the hydrogen flame, the heat from the first position 110 is less likely to be transferred to the second position 120, thus suppressing the temperature rise of the second position 120. This prevents the temperature rise of the wire 91 connected to the second position 120, and suppresses fluctuations in the resistance of the wire 91 due to the temperature rise of the wire 91. Therefore, it is possible to suppress the occurrence of noise in the ion detection signal transmitted by the wire 91. Consequently, noise in the ion detection signal can be reduced in the FID 10A. This improves the measurement accuracy of the gas chromatograph 100.
[0028] As mentioned above, by reducing the cross-sectional area of the collector 1A in the plane perpendicular to the X-axis direction, the thermal resistance increases, which can reduce noise in the ion detection signal at FID 10A. However, it is preferable that the collector 1A has a heat capacity sufficient to mitigate the effects of hydrogen flame fluctuations at the first position 110. It is also preferable that the collector 1A has a heat capacity sufficient to mitigate the effects of disturbances (for example, air conditioning wind) through the opening 28 at the second position 120. Therefore, when the portion around the first position 110 is designated as the first portion 11, the portion around the second position 120 as the second portion 12, and the portion connecting the first portion 11 and the second portion 12 as the third portion 13, the collector 1A of one embodiment shown in Figure 1 has a shape that includes a thick first portion 11, a thick second portion 12, and a third portion 13A that includes a thin region 130. In the example in Figure 1, the first portion 11 is the portion facing the nozzle 4, and the second portion 12 is the portion physically connected to the support material 3. Since at least a portion of the thickness of the third portion 13A is thinner than the thickness of the first portion 11, the cross-sectional area of at least a portion of the third portion 13A on a plane perpendicular to the X-axis direction is smaller than the cross-sectional area of the first portion 11 on a plane perpendicular to the X-axis direction. Therefore, the thermal resistance of the third portion 13A is greater than that of the third portion 13Z, which has the same thickness as the first portion 11 of the collector 1Z in the comparative example in Figure 2. Thus, even if the first portion 11 of the collector 1A becomes hot when it comes into contact with the hydrogen flame, the heat from the first portion 11 is not easily transferred to the second portion 12, and the temperature rise of the second portion 12 can be suppressed.
[0029] Furthermore, it is preferable that the support member 3 is configured to support the collector 1A in the second portion 12, as shown in the example in Figure 1. In other words, it is preferable that the support member 3 is configured to contact the collector 1A in the second portion 12 rather than in the first portion 11 or the third portion 13A. The reason for this is as follows.
[0030] As described above, the collector 1A is configured such that heat from the first part 11 is not easily transferred to the second part 12. Therefore, the temperature of the second part 12 is kept lower than that of the first part 11 and lower than that of the third part 13A. Consequently, when the support material 3 supports the collector 1A, by configuring it to support the second part 12, which is the coldest part of the collector 1A, heat is not easily transferred to the support material 3, and thus the rise in the temperature of the support material 3 can be suppressed.
[0031] Even though the support material 3 is provided as an insulator between the collector 1A and the body 2, if the temperature of the support material 3 rises, the dielectric strength of the support material 3 decreases and becomes unstable. Consequently, the voltage difference between the collector 1A and the body 2 becomes unstable. Therefore, the signal of the current generated by ion collection is reduced or its value becomes unstable. As a result, as the temperature of the support material 3 rises, the noise in the ion detection signal increases.
[0032] Therefore, when the support material 3 supports the collector 1A with the second part 12, the noise in the ion detection signal is suppressed more than when the support material 3 supports the collector 1A with the first part 11 or with the third part 13A.
[0033] Furthermore, in terms of suppressing the temperature rise of the second position, a longer distance between the first position 110 and the second position 120 is preferable, and in particular, in terms of suppressing the temperature rise of the second part 12, a longer third part 13A is preferable. However, due to the structure of the FID, there is a limit to the length of the third part 13A, so it is considered more effective to make the third part 13A thinner. In addition, in order to reduce the temperature rise of the second part 12, it is also conceivable to provide equipment to actively cool the second part 12, but this complicates the structure, so it is preferable to make the third part 13A thinner. For example, if an air-cooling fan is provided on top of the collector 1A and cool air is sent to the second part 12, there are concerns about problems such as difficulty in securing space to install the air-cooling fan, increased costs due to the installation of the air-cooling fan, and increased noise due to the cool air.
[0034] In the embodiments described above, an example was shown in which the entire third portion 13A is formed to be thinner than the first portion 11. However, the entire third portion does not necessarily need to be formed to be thinner than the first portion. As long as the effects of this embodiment are achieved, the third portion may be formed to be locally thinner than the first portion, as shown in the following Modifications 1 to 3.
[0035] [Structural Variations of Part 3] Figures 3 to 5 are schematic diagrams of FID10B to FID10D relating to Modification 1 to Modification 3, respectively.
[0036] Figure 3 shows a collector 1B according to Modification 1, in which a groove (constriction) structure is formed in a part of the third portion 13Z of the collector 1Z according to the comparative example. The thickness of the third portion 13B of the collector 1B is the same as that of the comparative example in areas other than the region 130B in which the groove structure is formed, but it becomes thinner in the region 130B, making it more difficult for heat to be transferred from bottom to top. Therefore, according to the collector 1B according to Modification 1, heat conduction from the first position 110 to the second position 120 is suppressed in region 130B. Thus, compared to the comparative example, heat conduction from the first position 110 to the second position 120, and heat conduction from the first portion 11 to the second portion 12 can be suppressed.
[0037] Figure 4 shows collector 1C according to modified example 2, in which the third portion 13Z of collector 1Z according to comparative example is machined into a tapered shape. According to collector 1C according to modified example 2, heat conduction from the first position 110 to the second position 120 is suppressed in the tapered region 130C. Therefore, compared to the comparative example, heat conduction from the first position 110 to the second position 120, and heat conduction from the first portion 11 to the second portion 12 can be suppressed.
[0038] Figure 5 shows a collector 1D according to Modification 3, in which multiple groove structures are formed in the third portion 13Z of the collector 1Z according to the comparative example. According to the collector 1D according to Modification 3, heat conduction from the first position 110 to the second position 120 is suppressed in the region 130D in which multiple groove structures are formed. Therefore, heat conduction from the first position 110 to the second position 120, and heat conduction from the first portion 11 to the second portion 12 can be suppressed more than in the comparative example or Modification 1. In addition, as shown in Figure 5, by forming multiple groove structures, the surface area of the third portion 13D (more specifically, the surface area in contact with the surrounding gas of the third portion 13D) can be increased, so that heat dissipation can be improved.
[0039] As described above, several shapes of the third part have been shown. The longer the length of the thin portion of the third part (vertical length), the greater the thermal resistance of the third part. Also, the thinner the thickness of the thin portion of the third part (radial thickness of the collector), the greater the thermal resistance of the third part. However, in order to maintain the strength of the collector and ensure sufficient functionality, the thin portion of the third part needs to have a certain thickness. Furthermore, as mentioned above, it is preferable that the upper and lower ends of the collector have a certain amount of heat capacity. Therefore, the length and thickness of the thin portion of the third part are appropriately designed to maintain the strength and function of the collector within the necessary range.
[0040] [Processing to Improve the Radiation Efficiency of the Collector and / or the Body] In addition to forming the thickness of at least a part of the region between the first position 110 and the second position 120 in the collector to be thinner than the thickness of the first position 110 as shown in the embodiments and modification examples 1 to 3, by performing processing to increase the radiation efficiency on the outer wall of the collector and / or the outer wall of the body, further, the temperature rise of the second part of the collector can be suppressed.
[0041] FIGS. 6 and 7 are schematic configuration diagrams of FID10E and FID10F respectively according to modification example 4 and modification example 5.
[0042] FIG. 6 shows a collector 1E according to modification example 4 in which processing to improve the radiation efficiency is performed on at least a part of the outer wall 172A of the collector 1A according to the embodiment. In one embodiment, at least a part of the outer wall 172E of the collector 1E is blackened. With this configuration, the heat radiation to the outside of the collector 1E increases. Therefore, the temperature rise of the collector 1E is reduced. Therefore, the temperature rise of the electric wire 91 and the support member 3 connected to the collector 1E is also reduced. Thereby, the noise of the ion detection signal can be reduced.
[0043] Note that the blackening may be surface oxidation of the metal or application of a black paint. The inside of the collector 1E may also be blackened.
[0044] Further, the processing to increase the radiation efficiency is not limited to blackening, and any processing that improves the radiation efficiency compared to the surface of the collector before processing (typically a metal surface) may be used. For example, a paint with a darker color than the metal surface may be applied.
[0045] FIG. 7 shows a body 2F according to Modification 4, in which at least a part of the outer wall 272 of the body 2 according to the embodiment is processed to increase the radiation efficiency. In one embodiment, at least a part of the outer wall 272F of the body 2F is blackened. With this configuration, heat dissipation to the outside of the body 2F increases. Therefore, the efficiency of discharging the heat released from the collector 1A into the body 2F to the outside through the body 2F is improved. Therefore, an increase in the temperature of the collector 1A can be suppressed. Therefore, the temperature rise of the electric wire 91 and the support member 3 connected to the collector 1A is also reduced. Thereby, the noise of the ion detection signal can be reduced.
[0046] Note that the blackening may be surface oxidation or black paint application. The inner wall 271F of the body 2F may also be blackened.
[0047] Further, the processing for improving the radiation efficiency is not limited to blackening, and any processing that improves the radiation efficiency compared to the surface of the body before processing (typically a metal surface) may be used. For example, a paint with a darker color than the metal surface may be applied.
[0048] Further, the processing for improving the radiation efficiency on the outer wall of the collector and / or the outside of the body can suppress the temperature rise of the collector even when performed on a collector in which the thickness of the third part is not formed thinner than the thickness of the first part as in the comparative example.
[0049] FIGS. 8 and 9 are schematic configuration diagrams of FID 10G and FID 10H according to Modification 6 and Modification 7, respectively.
[0050] Figure 8 shows the FID10G according to Modification 6, in which at least a portion of the outer wall 172Z of the collector 1Z of the FID10Z according to Comparative Example is processed to improve radiation efficiency. Because at least a portion of the outer wall 172G of the collector 1G of the FID10G is processed to improve radiation efficiency, the heat dissipation to the outside of the collector is greater than that of the collector 1Z of the FID10Z. As a result, the temperature rise of the collector is suppressed in the FID10G, and the temperature rise of the electric wire 91 and support material 3 connected to the collector is also reduced. Therefore, the noise in the ion detection signal can be reduced with the FID10G compared to the FID10Z.
[0051] Figure 9 shows the FID10H according to Modification 7, in which at least a portion of the outer wall 172Z of the body 2 of the FID10Z according to Comparative Example is processed to improve radiation efficiency. Because at least a portion of the outer wall 272H of the body 2H of the FID10H is processed to improve radiation efficiency, heat dissipation from the collector to the outside of the body through the body is greater than that of the body 2 of the FID10Z. As a result, in the FID10H, the temperature rise of the collector is suppressed, and the temperature rise of the electric wire 91 and support material 3 connected to the collector is also reduced. Therefore, with the FID10H, the noise of the ion detection signal can be reduced compared to the FID10Z.
[0052] [Aspects] The above-described exemplary embodiments will be understood by those skilled in the art to be specific examples of the following aspects.
[0053] (Section 1) The flame ionization detector according to the first embodiment comprises a nozzle for generating a hydrogen flame, a collector positioned at a distance from the nozzle in its extension direction for collecting ions generated by ionizing a sample with the hydrogen flame, a cylindrical body extending in the extension direction which houses the nozzle and the collector in its internal space, and an insulating support material that physically connects the inner wall of the body and the outer wall of the collector. The body supports the support material and the nozzle at positions separated in the extension direction. The collector is connected to a wire that transmits a signal of the current generated by the collection of ions to a processing device. The collector is cylindrical in shape. A first position, which is the end face of the collector proximal to the nozzle, and a second position, which is the position of the collector connected to the wire, are separated in the extension direction. In the collector, the thickness of at least a portion of the region between the first position and the second position is thinner than the thickness of the first position.
[0054] According to the flame ionization detector described in paragraph 1, the thermal resistance between the first and second positions is greater than when the thickness between the first and second positions is generally the same as that of the first position. Therefore, even if the first position becomes hot when in contact with the hydrogen flame, the heat from the first position is less likely to be transferred to the second position, thus suppressing the temperature rise of the second position. This prevents the temperature rise of the wire connected to the second position from rising, and suppresses fluctuations in the resistance of the wire due to the temperature rise of the wire. Therefore, in the flame ionization detector, noise in the ion detection signal can be reduced.
[0055] (Section 2) In the collector of the flame ionization detector described in Section 1, the entire area between the first portion around the first position and the second portion around the second position is formed to be thinner than the first position.
[0056] (Section 3) In the collector of the flame ionization detector described in Section 1, the area between the first portion around the first position and the second portion around the second position is locally thinner than the first position.
[0057] (Clause 4) In the flame ionization detector described in any one of paragraphs 1 to 3, the support material supports the collector in a second portion around the second position.
[0058] According to the flame ionization detector described in Section 4, the temperature of the second part is kept lower than that of the first part and the third part. Therefore, when the support material supports the collector at the second part, less heat is transferred to the support material than when the collector is supported at the first part or at the third part, and the temperature of the support material does not rise easily. Consequently, the decrease in dielectric strength caused by the rise in the temperature of the support material can be suppressed. This reduces the generation of noise in the ion detection signal.
[0059] (Item 5) In the flame ionization detector described in any one of items 1 to 4, at least a portion of the outer wall of the collector is processed to increase the radiation efficiency.
[0060] According to the flame ionization detector described in Section 5, heat dissipation to the outside of the collector is increased. Therefore, the rise in collector temperature is reduced. Consequently, the temperature rise of the wires and support materials connected to the collector is also reduced. This reduces noise in the ion detection signal.
[0061] (Item 6) In the flame ionization detector described in any one of items 1 to 5, at least a portion of the outer wall of the body is processed to increase the radiation efficiency.
[0062] According to the flame ionization detector described in Section 6, more heat is dissipated to the outside of the body. Therefore, the efficiency of releasing heat released from the collector into the body to the outside through the body is improved. Consequently, the rise in collector temperature can be suppressed. Consequently, the temperature rise of the wires and support materials connected to the collector is also reduced. As a result, noise in the ion detection signal can be reduced.
[0063] (Section 7) The flame ionization detector according to the second embodiment comprises a nozzle for generating a hydrogen flame, a collector positioned at a distance from the nozzle in its extension direction for collecting ions generated by ionizing a sample with the hydrogen flame, a cylindrical body extending in the extension direction and housing the nozzle and collector in its internal space, and an insulating support material that physically connects the inner wall of the body and the outer wall of the collector. The body supports the support material and the nozzle at a position separated in the extension direction. The collector is connected to a wire that transmits a signal of the current generated by the collection of ions to a processing device. The collector is cylindrical in shape. At least a portion of the outer wall of the collector is blackened.
[0064] According to the flame ionization detector described in Section 7, the rise in collector temperature can be suppressed. This reduces noise in the ion detection signal.
[0065] (Item 8) A gas chromatograph equipped with a flame ionization detector as described in any one of items 1 to 7.
[0066] The gas chromatograph described in paragraph 8 can improve the measurement accuracy of the gas chromatograph.
[0067] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope of equivalents of the claims are intended.
[0068] 1A-1G, 1Z Collector, 2, 2F, 2H Body, 3 Support material, 4 Nozzle, 10A-10H, 10Z FID, 11 First part, 12 Second part, 13, 13A-13E, 13G, 13Z Third part, 21-23 First to third flow paths, 25, 26, 119 End face, 28 Opening, 29 Internal space, 31 First support material, 32 Second support material, 91 Electric wire, 97 Column, 98 Sample injection device, 99 Controller, 100 Gas chromatograph, 110 First position (end face), 120 Second position, 130A-130E Region, 172A-172E, 172G, 172Z, 272, 272F, 272H Outer wall, 271, 271F Inner wall.
Claims
1. A hydrogen flame ionization detector comprising: a nozzle for generating a hydrogen flame; a collector positioned at a distance from the nozzle in its extension direction for collecting ions generated by ionizing a sample with the hydrogen flame; a cylindrical body extending in the extension direction, housing the nozzle and the collector in its internal space; and an insulating support material physically connecting the inner wall of the body and the outer wall of the collector, wherein the body supports the support material and the nozzle at positions separated in the extension direction; the collector is connected to a wire that transmits a signal of the current generated by the collection of the ions to a processing device; the collector is cylindrical in shape; a first position, which is the end face of the collector proximal to the nozzle, and a second position, which is the position of the collector connected to the wire, are spaced apart in the extension direction; and in the collector, the thickness of at least a portion of the region between the first position and the second position is thinner than the thickness of the first position.
2. The flame ionization detector according to claim 1, wherein in the collector, the entire area between the first portion around the first position and the second portion around the second position is formed to be thinner than the first position.
3. The flame ionization detector according to claim 1, wherein in the collector, the space between the first portion around the first position and the second portion around the second position is locally thinner than the first position.
4. The flame ionization detector according to claim 1, wherein the support material supports the collector in a second portion around the second position.
5. The flame ionization detector according to claim 1, wherein at least a portion of the outer wall of the collector is processed to increase the radiation efficiency.
6. The flame ionization detector according to claim 1, wherein at least a portion of the outer wall of the body is processed to increase the radiation efficiency.
7. A hydrogen flame ionization detector comprising: a nozzle for generating a hydrogen flame; a collector positioned at a distance from the nozzle in the extension direction of the nozzle and for collecting ions generated by ionizing a sample with the hydrogen flame; a cylindrical body extending in the extension direction and housing the nozzle and the collector in its internal space; and an insulating support material that physically connects the inner wall of the body and the outer wall of the collector, wherein the body supports the support material and the nozzle at a distance from each other in the extension direction; the collector is connected to a wire that transmits a signal of the current generated by the collection of the ions to a processing device; the collector is cylindrical; and at least a portion of the outer wall of the collector is blackened.
8. A gas chromatograph comprising the flame ionization detector described in claim 1.