A pulsed flame photometric detection device and method

Abstract

The application belongs to the technical field of flame detection, and specifically discloses a pulse type flame photometric detection device and method, which comprises a detector body, a combustion chamber, an ignition chamber, a combustion chamber air inlet pipe, an ignition chamber air inlet pipe, a light transmission assembly and a signal processing assembly, and an igniter is installed on the ignition chamber; a flow-through cavity is formed in the detector, the combustion chamber is installed in the flow-through cavity, the ignition chamber is located above the combustion chamber and is in communication with the combustion chamber; the ignition chamber air inlet pipe is in communication with the ignition chamber, the combustion chamber air inlet pipe is in communication with the combustion chamber, and the combustion chamber is also connected with a sample inlet pipe for feeding the measured substance; one end of the light transmission assembly is located in the flow-through cavity and on one side of the combustion chamber, the opposite side of the light transmission assembly is provided with a reflector, the reflector and the light transmission assembly are located on both sides of the combustion chamber, and the reflector is installed on the detector body, and the signal processing assembly is used for collecting and receiving the photons transmitted in the light transmission assembly. The application can reduce noise photons and improve sensitivity.

Description

Technical Field

[0001] This invention relates to the field of flame detection technology, and specifically to a pulsed flame photometric detection device and method. Background Technology

[0002] Gas chromatography is used to detect specific elements (and their compounds) in samples. It is a qualitative analysis method and is generally used in conjunction with various detectors. Currently, the flame photometric detector (FPD) is commonly used. The FPD is a highly selective and sensitive detector for phosphorus and sulfur-containing compounds. When the analyte burns in a hydrogen-rich flame, phosphorus-containing organic compounds mainly emit characteristic light at a wavelength of 526 nm in the form of HPO fragments, while sulfur-containing compounds emit characteristic light at a wavelength of 394 nm in the form of S2 molecules. The emitted characteristic light passes through a light transmission component and then enters a photomultiplier tube (PMT). The PMT converts the optical signal into an electrical signal, which is then amplified and recorded by a microcurrent for easy analysis.

[0003] The existing FPD detectors use continuous flame combustion, which easily generates background noise, causing unwanted interfering photons to be collected in the characteristic light entering the photomultiplier tube; in addition, the existing FPD detectors have poor sensitivity and low selectivity. Summary of the Invention

[0004] This invention provides a pulsed flame photometric detection device and method, with the aim of reducing noise photons and improving sensitivity.

[0005] This invention is achieved through the following technical solution: a pulsed flame photometric detection device, comprising a detector body, a combustion chamber, an ignition chamber, a combustion chamber air inlet pipe, an ignition chamber air inlet pipe, a light transmission component, and a signal processing component, wherein an igniter is installed on the ignition chamber;

[0006] The detector has a flow chamber, the combustion chamber is installed in the flow chamber, the ignition chamber is located above the combustion chamber, and the ignition chamber and the combustion chamber are in communication with each other;

[0007] The ignition chamber air inlet pipe is connected to the ignition chamber, the combustion chamber air inlet pipe is connected to the combustion chamber, and the combustion chamber is also connected to an injection tube for introducing the test substance.

[0008] One end of the light-transmitting component is located inside the flow cavity and on one side of the combustion chamber. A reflector is provided directly opposite the light-transmitting component. The reflector and the light-transmitting component are located on opposite sides of the combustion chamber, and the reflector is mounted on the detector body. The signal processing component is used to collect and receive photons transmitted within the light-transmitting component.

[0009] This solution provides a pulsed flame photometric detection device, which can ignite the ignition chamber and extend the flame into the combustion chamber, thereby generating a flame in the combustion chamber. The emitted photons are propagated through the light transmission component and then collected and received by the signal processing component, which facilitates the analysis of the properties of the substance being tested.

[0010] In this design, the flame extinguishes after the gases in the combustion and ignition chambers are used up, thus achieving a pulsed flame effect. This facilitates the elimination of noisy photons based on the different wavelengths and emission times of different photons, obtaining the desired characteristic photons, thereby improving the sensitivity and selectivity of the detector.

[0011] The reflector in this design can reflect photons, collecting and reflecting as many photons as possible from the side of the combustion chamber to the light transmission component, allowing the photons to propagate along the light transmission component and reducing photon loss.

[0012] Furthermore, the detector body has an air intake channel located between the combustion chamber and the ignition chamber. The top wall of the flow chamber and the air intake channel are provided with interconnected air holes. The air intake pipe of the ignition chamber is connected to the flow chamber.

[0013] The bleed air passage acts as an intermediate bridge connecting the combustion chamber and the ignition chamber, guiding the gas that has been introduced into the flow chamber to the ignition chamber through the bleed air passage and air holes.

[0014] Furthermore, an air inlet is connected to the bottom of the flow chamber, a lower support block is connected to the top of the air inlet, an upper support block is connected to the top of the flow chamber, and the bottom of the upper support block and the top of the lower support block are provided with mutually facing slots. The two ends of the combustion chamber are respectively locked in the slots of the upper support block and the lower support block, and one end of the sample inlet tube passes through the air inlet and the lower support block in sequence to communicate with the combustion chamber.

[0015] The upper support block has a central hole in the center, which communicates with the air intake channel and the gas chamber. The top of the upper support block has an annular groove, and the bottom of the annular groove has multiple air holes along its circumference, which communicate with the flow cavity and the air intake channel.

[0016] In this design, the air intake nozzle is connected to the bottom of the flow chamber, which not only seals the flow chamber but also facilitates the installation of the lower support block. In this design, both ends of the combustion chamber are respectively locked in the slots of the upper and lower support blocks, thereby achieving the installation and fixation of the combustion chamber. This assembly method is simple.

[0017] In addition, the central hole on the upper support block and the air intake channel on the detector body in this design can connect the combustion chamber and the ignition chamber, facilitating the ignition of the gas in the combustion chamber to generate a flame. At the same time, the annular groove and multiple air holes on the upper support block can guide the gas entering the combustion chamber into the ignition chamber for easy ignition. Compared with the method of directly opening multiple air holes on the upper support block, this design opens an annular groove on the upper support block, with the top of the air hole located inside the annular groove. With this setting, when the flame in the ignition chamber is generated and spreads downwards, it can be extinguished when it comes into contact with the annular groove, preventing it from burning downwards through the air hole. This ensures that the ignition chamber will only ignite the mixed gas in the combustion chamber through the central hole of the upper support block.

[0018] Furthermore, the combustion chamber and the ignition chamber are arranged alternately, and the air intake channel is perpendicular to and interconnected with the ignition chamber and the combustion chamber.

[0019] In this design, the combustion chamber and ignition chamber are staggered, which ensures that the gas introduced into the ignition chamber and the combustion chamber does not interfere with each other. If the two are arranged vertically opposite each other, the gas passage design leading to the ignition chamber and the combustion chamber will be more complicated. In this design, the two can be connected by only the bleed gas passage, which facilitates ignition.

[0020] Furthermore, the volume of the combustion chamber is 35-39 microliters.

[0021] The combustion chamber in this design has a small volume and low gas consumption, and the small volume of the combustion chamber can increase the equivalent concentration of the substance being tested.

[0022] Furthermore, the signal processing component includes a multiplier tube sleeve and a photomultiplier tube, with the photomultiplier tube located inside the multiplier tube sleeve;

[0023] The light transmission component includes a support tube and a light guide rod. The light guide rod is located inside the support tube. Both ends of the support tube are open. The two ends of the support tube are respectively connected to the photomultiplier tube sleeve and the detector body. A filter is installed inside the photomultiplier tube sleeve and between the photomultiplier tube and the light guide rod.

[0024] In this scheme, the signal processing component uses a photomultiplier tube to collect photons and convert them into electrical signals; the light guide rod in the light transmission component allows photons to propagate along the light guide rod, and after being filtered by a filter to remove noise photons, they are received by the photomultiplier tube and converted into electrical signals for easy analysis and processing.

[0025] A pulsed flame photometric detection method uses a pulsed flame photometric detection device as described above. A mixture of hydrogen and air is introduced into the ignition chamber and combustion chamber through the ignition chamber inlet pipe and the combustion chamber inlet pipe, respectively. At the same time, the sample injection tube introduces the analyte into the combustion chamber. When the mixture reaches the ignition chamber, the igniter starts ignition, thereby generating a flame in the ignition chamber. The flame in the ignition chamber extends downward into the combustion chamber until it extinguishes at the bottom of the combustion chamber. During the extension process, photons are generated in the combustion chamber. The photons are reflected by a mirror into the light transmission component for transmission and are collected and received by the signal processing component.

[0026] Furthermore, by setting the time for the signal processing component to receive different photons, noisy photons are eliminated, while the reception of the required characteristic photons is delayed.

[0027] Furthermore, gated electronics are used to expel noise photons outside the gate window of the photomultiplier tube.

[0028] Furthermore, the ignition chamber intake pipe fills the ignition chamber with a hydrogen-containing air mixture, and the combustion chamber intake pipe fills the combustion chamber with a hydrogen-rich air mixture.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] This invention discloses a pulsed flame photometric detection device and method. The device involves introducing hydrogen-rich air mixture into the combustion chamber through an air inlet pipe, introducing the analyte into the combustion chamber through a sample inlet pipe, and introducing a hydrogen-containing air mixture into the ignition chamber through an air inlet pipe. An igniter then ignites the mixture of the analyte and the hydrogen-rich air mixture within the combustion chamber, thereby generating a flame. In use, the ignition chamber and the combustion chamber can be filled with equal proportions of gas, ensuring that the gas in both chambers burns completely and the flame extinguishes simultaneously. Gas is then introduced again for re-ignition, achieving the effect of pulsed flame combustion.

[0031] The substance being tested is ignited by a hydrogen-rich flame in the combustion chamber and produces chemiluminescence (different substances produce chemiluminescence with different wavelengths). The characteristic photons produced by the combustion of the substance being tested are propagated through the light transmission component and collected by the signal processing component and converted into electrical signals for easy analysis.

[0032] Due to the various substances in the pulsed combustion flame ( (e.g., possessing specific chemiluminescence spectra and specific chemiluminescence delay characteristics). The pulsed flame in this scheme enables the light-transmitting component to selectively filter photons based on their emission times. For example, some photons that do not need to be collected have earlier and shorter emission times, while the photons we need to analyze, such as... , The emission time is later and the emission duration is longer. Therefore, when the photonic material we need is emitted, the emission of the photonic material we don't need is completed. This allows us to filter out the photonic material that was emitted earlier and reduce noise. Therefore, this pulsed flame photometric detection device can easily separate the emission of the desired material from that of the unwanted material in terms of time, thus enhancing its selectivity.

[0033] This scheme combines the differences in emission lifetimes of specific substances with the dynamics of the propagating flame, allowing the use of time and wavelength information to improve the selectivity of the PFPD detector (i.e., a pulsed flame photometric detection device in this invention), reduce observed noise, and increase sensitivity. The propagating flame utilizes a lower combustible gas flow rate, increasing the relative analyte concentration. In practical applications, gated electronics can also be used for noise suppression outside a designated gate window, further improving the detection rate of the pulsed flame photometric detection device. Attached Figure Description

[0034] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0035] Figure 1 This is a schematic diagram of an embodiment of the pulsed flame photometric detection method of the present invention;

[0036] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0037] Figure 3 This is the time-resolved spectrum of pulsed flame emission.

[0038] The attached diagram shows the markings and corresponding component names:

[0039] The detector body 100, combustion chamber 1, flow chamber 2, ignition chamber 3, igniter 4, reflector 7, light guide rod 8, support tube 80, filter 10, photomultiplier tube 11, sample inlet tube 14, combustion chamber inlet pipe 15, ignition chamber inlet pipe 16, multiplier tube sleeve 18, connecting sleeve 19, back tightening nut 20, air intake channel 21, connecting port 22, air inlet nozzle 23, upper support block 24, annular groove 241, air hole 242, center hole 243, lower support block 25. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0041] Example 1

[0042] like Figure 1 As shown, this embodiment 1 provides a pulsed flame photometric detection device, including a detector body 100, a combustion chamber 1, an ignition chamber 3, a combustion chamber inlet pipe 15, an ignition chamber inlet pipe 16, a light transmission component, and a signal processing component.

[0043] In this embodiment, a flow cavity 2 and an air intake channel 21 are provided inside the detector body 100. The flow cavity 2 is located in the lower part of the detector body 100, and the air intake channel is located in the middle part of the detector body 100.

[0044] Combustion chamber 1 is installed inside flow chamber 2, and ignition chamber 3 is installed on detector body 100 and above combustion chamber 1, i.e., ignition chamber 3 is installed on the upper body. Air intake channel 21 is located between combustion chamber 1 and ignition chamber 3 and communicates with both. In this embodiment, combustion chamber 1 and ignition chamber 3 are staggered, meaning they are not on the same straight line. Air intake channel 21 is perpendicular to and communicates with ignition chamber 3 and combustion chamber 1. In this embodiment, ignition chamber 3 is a pipe structure, with a connecting port 22 at its bottom. The connecting port 22 is perpendicular to and communicates with air intake channel 21, thus enabling communication between ignition chamber 3 and combustion chamber 1 through connecting port 22 and air intake channel 21. Igniter 4 is installed on ignition chamber 3, used to ignite the gas mixture inside ignition chamber 3.

[0045] A gas hole 242 is provided between the top wall of the flow chamber 2 and the gas inlet channel 21. The ignition chamber inlet pipe 16 is connected to the flow chamber 2, and the combustion chamber inlet pipe 15 is connected to the combustion chamber 1. The combustion chamber 1 is also connected to a sample inlet pipe 14 for introducing the analyte. Specifically:

[0046] The bottom of the flow chamber 2 is connected to an air inlet 23. In this embodiment, the upper part of the air inlet 23 extends into the flow chamber 2 and is threadedly connected to the inner wall of the flow chamber 2. A sealing ring is installed between the air inlet 23 and the bottom of the flow chamber 2 to ensure the sealing of the flow chamber 2. An air inlet channel communicating with the gas chamber is opened inside the air inlet 23.

[0047] The top of the air inlet 23 is connected to a lower support block 25, and the top of the flow cavity 2 is connected to an upper support block 24. In this embodiment, the lower support block 25 is threadedly connected to the upper part of the air inlet 23. The top of the lower body of the detector body 100 is provided with a groove, which forms a stepped hole shape with the flow cavity 2. The upper support block 24 is installed in the groove and located at the top of the flow cavity 2.

[0048] The bottom of the upper support block 24 and the top of the lower support block 25 are provided with mutually facing slots. The two ends of the combustion chamber 1 are tightly locked in the slots of the upper support block 24 and the lower support block 25, so that the combustion chamber 1 is fixed in the flow cavity 2 under the restriction of the upper support block 24 and the lower support block 25.

[0049] One end of the injection tube 14 passes sequentially through the air inlet channel of the air inlet nozzle 23 and the lower support block 25 to communicate with the combustion chamber 1. In this embodiment, the bottom of the slot of the lower support block 25 has an insertion hole, the inner diameter of which is larger than the outer diameter of the injection tube 14. This creates a gap between the injection tube 14 and the insertion hole after it passes through the lower support block 25, allowing the air inlet channel of the air inlet nozzle 23 to communicate with the combustion chamber through the insertion hole. In this embodiment, a sealing ring is provided between the combustion chamber 1 and the slot of the lower support block 25 to prevent gas entering from the air inlet nozzle 23 from leaking out of the combustion chamber 1.

[0050] In this embodiment, the sample inlet tube 14 is a quartz capillary tube with a small inner diameter, used to introduce the substance to be tested. Thus, the sample inlet nozzle of the combustion chamber 1 is directly replaced by a quartz capillary tube.

[0051] In this embodiment, one end of the combustion chamber intake pipe 15 passes through one side of the intake nozzle 23 and communicates with the intake channel of the intake nozzle 23, thereby connecting with the combustion chamber 1 through the intake nozzle 23, which facilitates the filling of gas into the combustion chamber 1. In this embodiment, the gas filled from the combustion chamber intake pipe 15 is a hydrogen-rich air mixture, and the gas filled from the ignition chamber intake pipe 16 is a hydrogen-containing air mixture.

[0052] In this embodiment, both the upper support block 24 and the lower support block 25 are made of PEEK material. PEEK material (polyether ether ketone) has high temperature resistance. The combustion chamber 1 is made of quartz material. In this embodiment, the combustion chamber 1 is specifically a highly transparent quartz tube. The volume of the combustion chamber 1 is 35-39 microliters. The small volume of the combustion chamber 1 can increase the equivalent concentration of the analyte, thereby improving the sensitivity of the detector.

[0053] The combustion chamber 1, the upper support block 24, and the lower support block 25 form an overall structure made of inert materials, which can minimize the adsorption of various adsorbent gases such as sulfides and phosphides, thereby ensuring the accuracy of detection.

[0054] Combination Figure 2As shown, a central hole 243 is provided in the center of the upper support block 24. The central hole 243 communicates with the air intake channel 21 and the gas chamber. An annular groove 241 is provided at the top of the upper support block 24. Multiple air holes 242 are provided at the bottom of the annular groove 241 along its circumference. The multiple air holes 242 are evenly distributed along the circumference of the annular groove 241. The air holes 242 communicate with the flow chamber 2 and the air intake channel 21.

[0055] Combination Figure 1 As shown, one end of the light-transmitting component is located inside the flow cavity 2 and on one side of the combustion chamber 1. The signal processing component is used to collect the characteristic photons transmitted within the light-transmitting component. A reflector 7 is located directly opposite the light-transmitting component. The reflector 7 and the light-transmitting component are located on opposite sides of the combustion chamber 1, and the reflector 7 is mounted on the detector body 100. Specifically:

[0056] like Figure 1 As shown, in this embodiment, the signal processing component includes a multiplier tube sleeve 18 and a photomultiplier tube 11. The photomultiplier tube 11 is located inside the multiplier tube sleeve 18. In this embodiment, one end of the multiplier tube sleeve 18 is detachably connected to a connecting sleeve 19. In this embodiment, the connecting sleeve 19 is threadedly connected to the multiplier tube sleeve 18, which facilitates disassembly and installation. A through hole is provided at the end of the connecting sleeve 19.

[0057] In this embodiment, mounting channels communicating with the flow cavity 2 are provided on both sides of the lower part of the detector body 100. The mounting channels are directly opposite the through holes at the ends of the connecting sleeve 19. One end of the light transmission component is connected to one of the mounting channels, and the reflector 7 is connected to the other mounting channel. The reflector 7 is positioned directly opposite the light transmission component. A set of mirror reflectors 7 is added opposite the light transmission component, which can collect and reflect as many photons as possible from the side of the combustion chamber 1 into the light transmission component.

[0058] In this embodiment, the light transmission component includes a support tube 80 and a light guide rod 8. The light guide rod 8 is located inside the support tube 80. Both ends of the support tube 80 are open, which facilitates the smooth transmission of characteristic photons from the light guide rod 8 to the photomultiplier tube. The two ends of the support tube 80 are respectively connected to the photomultiplier tube sleeve 18 and the detector body 100. Specifically, in this embodiment, the two ends of the support tube 80 extend into the through hole of the connecting sleeve 19 and the mounting channel on the lower body side of the detector body 100, and are threadedly connected to the through hole of the connecting sleeve 19 and the mounting channel of the detector body 100. A sealing ring is provided between the support tube 80 and the through hole of the connecting sleeve 19 and the mounting channel to ensure the airtightness of the light transmission component.

[0059] In this embodiment, the light guide rod 8 is a high-transmittance quartz light guide rod. Both ends of the light guide rod 8 are polished to form mirror surfaces. Various characteristic photons generated by the combustion of the test substance in the combustion chamber 1 propagate from the inside of the light guide rod 8 through the side wall of the light guide rod 8 to the surrounding areas. In this embodiment, a silver mirror coating 9 is plated on the outer circumference of the light guide rod 8 and the mirror surfaces at both ends. That is, a silver plating process is used on the outer circumference of the light guide rod 8 and the mirror surfaces at both ends to ensure that various photons at different angles are refracted and propagated within the quartz rod as much as possible, reducing photon loss during propagation, enhancing the collection of weak excitation light signals, and improving the weak light detection capability. Compared with the traditional structure, the light transmission component designed in this embodiment can greatly improve the light collection efficiency of the photomultiplier tube 11, increase the sensitivity of the detector, and lower the minimum detection limit.

[0060] In this embodiment, the support tube 80 is made of bakelite with a thermal conductivity between 0.15 and 19. The detector body 100 is made of 316 stainless steel and can reach a maximum temperature of 300°C. This structural design is used for the light transmission component between the detector and the photomultiplier tube 11. Various photons are propagated through the highly transparent quartz light guide rod 8, whose thermal conductivity is only between 1.3 and 1.65 at ≤300°C. The distance between the detector body 100 and the photomultiplier tube 11 is 30 mm. After the high temperature of the detector body 100 is blocked by the highly transparent quartz light guide rod and the bakelite support tube 80, the temperature of the photomultiplier tube 11 can be kept basically consistent with the ambient temperature, avoiding affecting the accuracy and performance of the photomultiplier tube 11.

[0061] like Figure 1 As shown, a filter 10 is installed inside the photomultiplier tube sleeve 18 and between the photomultiplier tube 11 and the light guide rod 8. Specifically, in this embodiment, the filter 10 is located inside the connecting sleeve 19 connected to the photomultiplier tube sleeve 18, and the characteristic photons passing through the light transmission component will be filtered by the filter 10.

[0062] In this embodiment, the connecting sleeve 19 is internally threaded with a back-tightening nut 20. The back-tightening nut 20 has a through hole coaxially opened in the center to facilitate the passage of characteristic photons and their reception by the photomultiplier tube 11. By tightening the back-tightening nut 20, the filter 10 is pressed and limited, so that the filter 10 is firmly fixed in the connecting sleeve 19. In this embodiment, sealing rings are provided between the filter 10 and the connecting sleeve 19 and the back-tightening nut 20, that is, sealing rings are provided on both sides of the filter. In this way, when the back-tightening nut 20 is tightened, the surface of the filter 10 will not be damaged, and an airtight seal can be ensured.

[0063] Example 2

[0064] The difference between this embodiment and Embodiment 1 is that this embodiment discloses a pulsed flame photometric detection method, using a pulsed flame photometric detection device as described in Embodiment 1 above. A mixture of hydrogen and air is introduced into the ignition chamber and the combustion chamber through the ignition chamber inlet pipe and the combustion chamber inlet pipe, respectively. At the same time, the sample tube introduces the substance to be tested into the combustion chamber. In this embodiment, the ignition chamber inlet pipe introduces a hydrogen-containing air mixture into the ignition chamber, and the combustion chamber inlet pipe introduces a hydrogen-rich air mixture into the combustion chamber. The hydrogen-containing air mixture first enters the flow chamber, then moves upward and enters the ignition chamber 3 through the air hole 242 on the upper support block 24.

[0065] When the gas mixture reaches the ignition chamber, the igniter ignites it, causing combustion and flame to be generated in the ignition chamber. The flame burns downwards into the combustion chamber and then extinguishes at the bottom of the combustion chamber. In use, the ignition chamber 3 and the gas chamber can be filled with equal proportions of gas through a proportional design, so that the gas in the ignition chamber 3 and the gas chamber in the gas chamber burns out at the same time and the flame extinguishes at the same time. Then, the gas mixture is added again for combustion, thereby achieving the effect of pulsed combustion.

[0066] During the entire combustion process, photons are generated in the combustion chamber. These photons are reflected by a mirror and transmitted into the light transmission component, where they are collected and received by a signal processing component.

[0067] In this embodiment, the substance being tested is ignited by a hydrogen-rich flame in the combustion chamber 1 and produces chemiluminescence (the wavelength of chemiluminescence produced by different substances varies). The photons produced by the combustion of the substance being tested are reflected by the reflector 7 to the light guide rod 8 in the light transmission component for propagation. After being filtered by the filter 10 to remove unwanted photons (i.e. noise photons), the photons are received by the photomultiplier tube 11 and converted into electrical signals for analysis.

[0068] In this embodiment, noise photons are eliminated by setting the time for the signal processing component to receive different photons, while the reception of the required characteristic photons is delayed. Specifically, in this embodiment, noise photons are eliminated outside the gate window of the photomultiplier tube by using a gate-controlled electronic device. The gate-controlled electronic device eliminates a large amount of flame background noise by adjusting the gate width and using a delayed gate integration method, thereby improving the sensitivity of the detector.

[0069] Due to the various substances in the pulsed combustion flame ( (e.g.,) possess specific chemiluminescence spectra and specific chemiluminescence delays. When measuring compounds containing sulfur, phosphorus, and carbon, the emission time of excited-state molecular fragments generated by the analyte in the flame is usually relatively long, while the emission time of other substances, such as hydrocarbon molecular fragments, is shorter. Therefore, the difference in emission time and wavelength can be utilized to first integrate the noise photons with very short emission times, such as... Figure 3As shown, the leftmost peak of each spectral line is a noise photon with a very short emission time (0-5ms). Therefore, when collecting characteristic photons, a gating electronic device is used to exclude this noise photon first, and then the characteristic photon is received by a photomultiplier tube about 5ms after emission. By combining the difference in emission lifetime of specific substances with the dynamics of the propagating flame, time and wavelength information can be used to improve the selectivity of the PFPD, reduce the observed noise, and improve the sensitivity.

[0070] It should be noted that the above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0071] In the description of this invention, it should be noted that the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0072] In the description of this document, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the attached drawings. They are only used to describe the relative positional relationship between the components or parts and do not specifically limit the specific installation orientation of each component or part.

[0073] In the description of this document, some terms may be used to indicate not only location or positional relationship, but also other meanings. For example, the term "above" may also be used in some cases to indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances.

[0074] In the description of this document, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0075] The structures, proportions, sizes, etc., drawn in the accompanying drawings in this application are only used to complement the content disclosed in this technical disclosure for those skilled in the art to understand and read, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modification of the structure, change of the proportion relationship, or adjustment of the size shall still fall within the scope of the technical content disclosed in this application, provided that it does not affect the effect and purpose that this application can produce.

[0076] The terminology used in this document is that which is currently widely used in the art in consideration of the functionality of this disclosure; however, these terms may vary depending on the intent, precedent, or new technology of those skilled in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of this disclosure. Therefore, the terminology used in this document should not be construed as simple names, but rather based on the meaning of the terms and the overall description of this disclosure.

[0077] This document uses flowcharts or text to illustrate the operational steps performed according to embodiments of this application. It should be understood that the operational steps in the embodiments of this application are not necessarily performed precisely in the order described. Instead, as needed, various steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more operations can be removed from these processes.

[0078] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A pulsed flame photometric detection device, characterized in that, It includes a detector body, a combustion chamber, an ignition chamber, a combustion chamber air inlet pipe, an ignition chamber air inlet pipe, a light transmission component, and a signal processing component, wherein an igniter is installed on the ignition chamber; The detector has a flow chamber, the combustion chamber is installed in the flow chamber, the ignition chamber is located above the combustion chamber, and the ignition chamber and the combustion chamber are in communication with each other; The ignition chamber air inlet pipe is connected to the ignition chamber, the combustion chamber air inlet pipe is connected to the combustion chamber, and the combustion chamber is also connected to an injection tube for introducing the test substance. One end of the light-transmitting component is located inside the flow cavity and on one side of the combustion chamber. A reflector is provided directly opposite the light-transmitting component. The reflector and the light-transmitting component are located on opposite sides of the combustion chamber, and the reflector is mounted on the detector body. The signal processing component is used to collect and receive photons transmitted within the light-transmitting component. The detector body has an air intake channel located between the combustion chamber and the ignition chamber. The top wall of the flow chamber and the air intake channel are connected by air holes. The air inlet pipe of the ignition chamber is connected to the flow chamber. The combustion chamber and the ignition chamber are staggered. The air intake channel is perpendicular to the ignition chamber and the combustion chamber and is connected to each other. The bottom of the flow chamber is connected to an air inlet, the top of the air inlet is connected to a lower support block, the top of the flow chamber is connected to an upper support block, the bottom of the upper support block and the top of the lower support block are provided with mutually facing slots, the two ends of the combustion chamber are respectively locked in the slots of the upper support block and the lower support block, and one end of the sample inlet tube passes through the air inlet and the lower support block in sequence to communicate with the combustion chamber. The upper support block has a central hole in the center, which is connected to the air intake channel and the gas chamber. The top of the upper support block has an annular groove, and the bottom of the annular groove has multiple air holes along its circumference, which are connected to the flow cavity and the air intake channel. The signal processing component includes a multiplier tube sleeve and a photomultiplier tube, wherein the photomultiplier tube is located inside the multiplier tube sleeve; The light transmission component includes a support tube and a light guide rod. The light guide rod is located inside the support tube. Both ends of the support tube are open. The two ends of the support tube are respectively connected to the photomultiplier tube sleeve and the detector body. A filter is installed inside the photomultiplier tube sleeve and between the photomultiplier tube and the light guide rod. The outer circumference and the mirror surfaces at both ends of the light guide rod are coated with a silver mirror coating.

2. The pulsed flame photometric detection device according to claim 1, characterized in that, The volume of the combustion chamber is 35-39 microliters.

3. A pulsed flame photometric detection method, using a pulsed flame photometric detection device as described in any one of claims 1-2, characterized in that, A mixture of hydrogen and air is introduced into the ignition chamber and combustion chamber through the ignition chamber inlet pipe and the combustion chamber inlet pipe, respectively. Simultaneously, the sample injection tube introduces the analyte into the combustion chamber. When the mixture reaches the ignition chamber, the igniter ignites it, causing combustion and flame generation. The flame extends downwards into the combustion chamber until it extinguishes at the bottom. During this extension process, photons are generated in the combustion chamber. These photons are reflected by a mirror into the light transmission component for transmission and are then collected and received by the signal processing component. By setting the timing of photon reception by the signal processing component, noisy photons are eliminated, while the characteristic photons required for reception are delayed.

4. The pulsed flame photometric detection method according to claim 3, characterized in that, Noise photons are expelled outside the gate window of the photomultiplier tube using gated electronics.

5. A pulsed flame photometric detection method according to any one of claims 3-4, characterized in that, The ignition chamber intake pipe fills the ignition chamber with a hydrogen-containing air mixture, and the combustion chamber intake pipe fills the combustion chamber with a hydrogen-rich air mixture.

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