Flow cell membrane inlet conductivity total organic carbon analyzer and method of operation

Abstract

The application relates to the technical field of water quality organic detection, and provides a flow cell type membrane conductance total organic carbon analyzer and a working method thereof. The flow cell type membrane conductance total organic carbon analyzer comprises a water sample pump with an input end arranged in a water sample to be measured, a UV oxidation chamber unit for oxidizing organic carbon in the water sample to be measured into carbon dioxide, a carbon dioxide exchange unit for exchanging the carbon dioxide in the water sample to be measured into deionized water, a three-way electromagnetic valve fixed on the carbon dioxide exchange unit, a deionized water pump with an input end connected to a water tank, a resin unit for removing ions from water in the water tank, and a conductivity measurement unit for measuring TC / IC conductivity. According to the application, the water sample is first divided into TC and IC paths, and then subjected to UV oxidation and membrane type CO2 exchange; subsequently, the measurement chamber is continuously circulated and the exchange chamber is intermittently stopped through three-way valve switching, so that the TOC measurement precision is significantly improved and the control is simplified.

Description

Technical Field

[0001] This application relates to the field of water quality organic detection technology, and in particular to a flow-through cell membrane conductivity total organic carbon analyzer and its working method. Background Technology

[0002] Total Organic Carbon (TOC) detection first involves oxidizing all organic carbon in the sample water to carbon dioxide. The total carbon or organic carbon content is then obtained by measuring changes in carbon dioxide levels or the solution's conductivity / other signals before and after oxidation. In practice, inorganic carbon is often measured simultaneously, and the total organic carbon content in the sample water is obtained by subtracting the inorganic carbon content from the total carbon content. TOC is a quantitative indicator of the total amount of organic pollutants in water and is widely used in process control, pure water quality monitoring, and semiconductor and pharmaceutical water supply. Its role is to reflect the level of organic pollution, ensure process and product quality, and support environmental compliance.

[0003] Existing TOC detection equipment and methods mainly fall into two categories: one is the combustion method, which measures CO2 using infrared or gas phase detectors after high-temperature catalytic combustion; the other is the wet / photochemical method, which detects CO2 or conductivity changes after wet chemical or UV / persulfate oxidation using differential conductivity, infrared, or electrochemical methods. Differential conductivity methods commonly employ two operating modes: continuous flow and stop-flow. Continuous flow measures conductivity before and after oxidation in two separate conductivity chambers and then compares the values. Stop-flow (thin-film conductivity, direct conductivity, etc.) involves stopping the flow in the measurement chamber and comparing conductivity values ​​before and after oxidation. Common analyzers integrate modules such as sampling pumps, UV oxidation chambers, combustion furnaces, and NDIR or conductivity units to achieve this process.

[0004] The above-mentioned detection schemes have insufficient measurement stability and anti-interference capabilities: the continuous flow method relies on constant flow rate and standard solution calibration and is sensitive to rheology, which can easily introduce measurement errors; the stop-flow method causes the material in the measurement chamber to dissolve ions into the water during the stagnant phase, which accumulates with the stagnant time, causing baseline drift and incorrect total carbon content / inorganic carbon content readings, thus making the TOC results unstable and susceptible to interference, and making it difficult to guarantee reliability in high-precision scenarios such as semiconductors and fine chemistry. Summary of the Invention

[0005] In view of this, this application provides a flow-through cell membrane conductivity total organic carbon analyzer and its operating method to solve the problems of insufficient stability and anti-interference in TOC measurement.

[0006] A first aspect of this application provides a flow-through cell membrane conductivity total organic carbon analyzer, the analyzer comprising: A water sample pump with its input end set in the water sample to be tested is used to extract the water sample to be tested to provide the power for the flow of the water sample to be tested, and to split the water sample to be tested into an inorganic carbon measurement flow path and a total carbon measurement flow path through the output end of the water sample pump. The ultraviolet oxidation chamber unit, which is set in the total carbon measurement flow path, is used to oxidize the organic carbon in the water sample to be tested into carbon dioxide. The carbon dioxide exchange unit for exchanging carbon dioxide in the water sample to be tested into deionized water is fixed on one side with a water sample-side IC inlet interface connected to the inorganic carbon measurement flow path, a water sample-side TC inlet interface connected to the output end of the ultraviolet oxidation chamber unit, a water sample-side IC outlet interface, and a water sample-side TC outlet interface. The other side of the carbon dioxide exchange unit is fixed with a deionized water-side inlet interface, an IC conductivity measurement inlet interface, a TC conductivity measurement inlet interface, and a deionized water-side outlet interface. A three-way solenoid valve fixed to the carbon dioxide exchange unit is used to control the flow path of deionized water in the carbon dioxide exchange unit. The input end is connected to the deionized water pump of the water tank, which is used to draw the deionized water in the water tank and provide the power for the flow of the deionized water; A resin unit disposed between the output end of the deionized water pump and the inlet interface of the deionized water is used to remove ions from the deionized water; and The conductivity measurement unit, connected to the IC conductivity measurement inlet interface and the TC conductivity measurement inlet interface, is used to measure the conductivity change data of the deionized water before and after absorbing carbon dioxide.

[0007] In an optional embodiment, the carbon dioxide exchange unit includes a water sample side chamber, a carbon dioxide permeation membrane, and a deionized water side chamber, which are stacked sequentially from bottom to top; wherein The water sample side chamber includes a water sample side pressure plate and a water sample side flow path plate disposed between the water sample side pressure plate and the carbon dioxide permeation membrane. The water sample side pressure plate has two first water sample IC connection holes and two first water sample TC connection holes that penetrate from front to back. The side of the water sample side flow path plate facing the carbon dioxide permeation membrane is provided with independent water sample TC flow path and water sample IC flow path. The first and last sides of the water sample TC flow path have second water sample TC connection holes that penetrate from front to back. The first and last sides of the water sample IC flow path have second water sample IC connection holes that penetrate from front to back. The deionized water side chamber includes a deionized water side pressure plate and a deionized water side flow path plate disposed between the deionized water side pressure plate and the carbon dioxide permeation membrane. The deionized water side pressure plate has two deionized water connection holes penetrating its front and rear, two conductivity measurement connection holes penetrating its front and rear, and three solenoid valve connection holes penetrating its front and rear, located below the three-way solenoid valve. The side of the deionized water side flow path plate facing the carbon dioxide permeation membrane has independent deionized water inlet flow paths and a first-mode flow path. The side of the deionized water side flow path plate facing the deionized water side pressure plate has a second-mode flow path. The flow path includes a deionized water inlet hole extending through the front and back on one side, and a C-connection hole extending through the front and back on the other side. The first flow path includes a NO connection hole extending through the front and back at the top, a TC exchange detection branch connecting the NO connection hole and parallel to the TC flow path of the water sample, and an IC exchange detection branch connecting the NO connection hole and parallel to the IC flow path of the water sample. The second flow path includes an NC connection port at the top, a TC detection branch connecting the NC connection port, and an IC detection branch connecting the NC connection port.

[0008] In an optional embodiment, the water sample side IC inlet interface and the water sample side IC outlet interface are respectively coaxially connected to the second water sample IC connection holes at both ends of the water sample IC flow path through the first water sample IC connection hole, forming a water sample IC transmission channel. The water sample side TC inlet interface and the water sample side TC outlet interface are respectively connected coaxially to the second water sample TC connection holes on both sides of the water sample TC flow path through the first water sample TC connection hole, forming a water sample TC transmission channel.

[0009] In an optional embodiment, the deionized water side inlet interface and the deionized water side outlet interface are respectively embedded in the deionized water connection hole, and the deionized water side inlet interface is coaxially connected to the deionized water inlet hole through the deionized water connection hole to form a deionized water inlet transmission channel. The three-way solenoid valve is connected to the C connection hole and the NO connection hole through the solenoid valve connection hole to form an exchange detection channel. The three-way solenoid valve is connected to the NC connection port through the solenoid valve connection hole to form a deionized water detection channel. The IC conductivity measurement inlet interface is connected to the bottom of the IC exchange detection branch through a conductivity measurement connection hole to form an IC exchange detection channel, and is also connected to the bottom of the IC detection branch to form a deionized water IC detection channel; The TC conductivity measurement inlet interface is connected to the bottom of the TC exchange detection branch through another conductivity measurement connection hole to form a TC exchange detection channel, and is also connected to the bottom of the TC detection branch to form a deionized water TC detection channel.

[0010] In one optional implementation, the water sample TC flow path, the TC exchange detection branch, the water sample IC flow path, and the IC exchange detection branch all adopt a U-shaped structure or a serpentine structure.

[0011] In an optional embodiment, the carbon dioxide permeation membrane is a Teflon film or an amorphous perfluorinated film.

[0012] In one optional embodiment, the ultraviolet oxidation chamber unit includes: an ultraviolet oxidation chamber, and an ultraviolet lamp built into the ultraviolet oxidation chamber.

[0013] A second aspect of this application provides a method for analyzing total organic carbon using a flow-through membrane conductivity method, the method comprising: The water sample to be tested is split into an inorganic carbon measurement water sample and an initial total carbon measurement water sample. The initial total carbon measurement water sample is subjected to ultraviolet oxidation treatment of organic carbon to obtain a total carbon measurement water sample. The test water in the preset water tank is subjected to ion removal treatment to obtain deionized water. The preset three-way solenoid valve is controlled to be in a preset first working state so as to deliver the deionized water to the preset IC exchange detection branch and the preset TC exchange detection branch. The inorganic carbon measurement water sample and the total carbon measurement water sample are respectively transported to the preset water sample IC flow path and the preset water sample TC flow path, and the three-way solenoid valve is switched to the preset second working state to diffuse the carbon dioxide in the inorganic carbon measurement water sample and the total carbon measurement water sample into the deionized water in the IC exchange detection branch and the deionized water in the TC exchange detection branch, respectively. The three-way solenoid valve is switched to the first working state so that the deionized water in the IC exchange detection branch is delivered to the preset conductivity measurement unit through the preset deionized water IC detection channel to obtain IC detection data, and the deionized water in the TC exchange detection branch is delivered to the conductivity measurement unit through the preset deionized water TC detection channel to obtain TC detection data. The total organic carbon concentration of the water sample to be tested is calculated based on the TC detection data and the IC detection data.

[0014] A third aspect of this application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the flow-through membrane conductivity total organic carbon analysis method as described above.

[0015] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the flow-through cell membrane conductivity total organic carbon analysis method as described above.

[0016] In summary, this application includes at least the following beneficial technical effects: 1. By designing the deionized water side to flow continuously within the conductivity measurement channel while allowing the exchange zone to pause, baseline drift caused by ions dissolving into the water from the measurement chamber material in the pause-flow method is avoided, thus ensuring the stability and accuracy of TC / IC measurements.

[0017] 2. The water sample is split into a TC path (which generates CO2 through UV oxidation) and an IC path, and exchanged with deionized water through a membrane-based selective carbon dioxide permeation. This allows TC and IC data to be obtained separately within the same carbon dioxide exchange unit, and the difference is used to derive TOC, simplifying the measurement process and reducing sample interference.

[0018] 3. The composite flow path design of the deionized water side flow path plate, combined with a single three-way solenoid valve, can switch between "continuous flow / interchange" modes, so as to achieve continuous refresh of the measurement chamber while retaining the exchange pause characteristics, thereby achieving stable measurement with fewer control components and reducing system control complexity and cost. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a flow-through cell membrane conductivity total organic carbon analyzer provided in Embodiment 1 of this application; Figure 2 This is an exploded structural diagram of a carbon dioxide exchange unit provided in Embodiment 2 of this application; Figure 3 This is a frontal structural diagram of a deionized water side flow path plate provided in Embodiment 3 of this application; Figure 4This is a cross-sectional view of the first flow path measurement process in the carbon dioxide exchange unit provided in Embodiment 4 of this application; Figure 5 This is a cross-sectional view of the second flow path measurement process in the carbon dioxide exchange unit provided in Embodiment 5 of this application; Figure 6 This is a schematic flowchart of a flow cell membrane conductivity total organic carbon analysis method provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application.

[0021] Explanation of icon numbers: 1. Water sample pump; 2. Ultraviolet oxidation chamber unit; 3. Carbon dioxide exchange unit; 301. Deionized water side inlet interface; 302. Deionized water side pressure plate; 303. Deionized water side flow path plate; 303a. Deionized water side inlet flow path; 303b. First flow path; 303c. Second flow path; 304. Carbon dioxide permeation membrane; 305. IC conductivity measurement inlet interface; 306. TC conductivity measurement inlet interface; 307. Deionized water side outlet interface; 308. Water sample side flow path plate; 309. Water sample side pressure plate; 310. Water sample side TC inlet interface; 311. Water sample side IC inlet interface; 312. Water sample side TC outlet interface; 313. Water sample side IC outlet interface; 4. Three-way solenoid valve; 5. Conductivity measurement unit; 6. Water tank; 7. Deionized water pump; 8. Resin unit. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] See Figure 1 The diagram shown is a structural schematic of a flow-through membrane conductivity total organic carbon analyzer according to Embodiment 1 of this application. The flow-through membrane conductivity total organic carbon analyzer provided in Embodiment 1 of this application has a water sample inlet and a deionized water supply outlet on both sides. The water sample inlet is used to collect the water sample to be tested and perform splitting and oxidation treatment; the deionized water supply outlet is used to provide a high-purity detection medium. The flow-through membrane conductivity total organic carbon analyzer provided in Embodiment 1 of this application includes a water sample pump 1, an ultraviolet oxidation chamber unit 2, a carbon dioxide exchange unit 3, a three-way solenoid valve 4, a conductivity measurement unit 5, a water tank 6, a deionized water pump 7, and a resin unit 8. All components are connected by pipes, connectors, and other fluid connections to form a complete detection flow path.

[0024] See also Figures 1 to 2 The internal connections of a flow-through membrane conductivity total organic carbon analyzer provided in this application are as follows: The input end of the water sample pump 1 is immersed in the water sample to be tested, and its output end is divided into two paths through a split connector: one path serves as the total carbon measurement path and is connected to the input end of the ultraviolet oxidation chamber unit 2; the other path serves as the inorganic carbon measurement path and is directly connected to the water sample side IC inlet interface 311 of the carbon dioxide exchange unit 3. The output end of the ultraviolet oxidation chamber unit 2 is connected to the water sample side TC inlet interface 310 of the carbon dioxide exchange unit 3. The input end of the deionized water pump 7 is connected to the water tank 6 containing pure water (i.e., test water), and its output end is connected in series with the resin unit 8 and then connected to the deionized water side inlet interface 301 of the carbon dioxide exchange unit 3. The three-way solenoid valve 4 is directly fixedly installed on the deionized water side pressure plate 302 of the carbon dioxide exchange unit 3 for internal flow path switching. The IC conductivity measurement inlet interface 305 and TC conductivity measurement inlet interface 306 of the carbon dioxide exchange unit 3 are respectively connected to the corresponding measurement channel input terminal of the conductivity measurement unit 5 through pipelines.

[0025] The water sample pump 1, serving as the core for sample introduction and fluid drive in a flow-through membrane conductivity total organic carbon analyzer, typically employs a corrosion-resistant miniature peristaltic pump or plunger pump. Its pump head connects to external piping via a flexible hose. By controlling the motor's speed or stroke, the extraction flow rate of the water sample can be precisely controlled, ensuring a stable and consistently proportioned sample supply to both the inorganic carbon and total carbon measurement paths, thus providing a foundation for accurate subsequent measurements.

[0026] The UV oxidation chamber unit 2 comprises a sealed UV oxidation chamber and a high-intensity UV lamp built into it. The UV oxidation chamber is typically made of quartz or a special UV-transmitting glass, and its interior is designed with spiral or baffled flow channels to extend the residence time of the water sample within the UV irradiation area. The 185nm and 254nm UV light emitted by the UV lamp efficiently and completely mineralizes all organic carbon compounds in the water sample flowing through the chamber, oxidizing them to carbon dioxide. This unit is a crucial pretreatment step for achieving total carbon (TC) measurement.

[0027] See also Figures 2 to 3 The carbon dioxide exchange unit 3 adopts a multi-layer flat-plate stacked structure to achieve selective transmembrane exchange of carbon dioxide between the water sample and deionized water. Specifically, the carbon dioxide exchange unit 3 includes a water sample side chamber, a carbon dioxide permeable membrane 304, and a deionized water side chamber stacked sequentially from bottom to top. The water sample side chamber includes a water sample side pressure plate 309 and a water sample side flow path plate 308; the deionized water side chamber includes a deionized water side flow path plate 303 and a deionized water side pressure plate 302.

[0028] The water sample side pressure plate 309 is located at the bottom layer and is made of 316L stainless steel using a CNC machine tool. It has two pairs of first water sample IC connection holes and first water sample TC connection holes that penetrate the plate. The water sample side flow path plate 308 is stacked on top of the water sample side pressure plate 309, also made of 316L stainless steel, with a recommended thickness of less than 1mm. Its surface facing the upper layer is etched with independent, serpentine or meandering water sample IC and TC flow paths. Each flow path has a second water sample IC connection hole or a second water sample TC connection hole that penetrates the plate at both ends. These holes are coaxially aligned with the corresponding connection holes on the lower water sample side pressure plate 309. The water sample side IC inlet interface 311 and the water sample side IC outlet interface 313 are connected to the water sample IC flow path on the water sample side flow path plate 308 through the connection hole on the water sample side pressure plate 309, forming a water sample IC transmission channel; similarly, the water sample side TC inlet interface 310 and the water sample side TC outlet interface 312 form a water sample TC transmission channel.

[0029] A carbon dioxide permeable membrane 304 is stacked on top of the water sample side flow path plate 308. It is made of Teflon (PTFE) film or amorphous perfluorinated film, with a recommended thickness of less than 40 micrometers. The carbon dioxide permeable membrane 304 has a high selective permeability for carbon dioxide gas, while effectively blocking the passage of liquid water and ions. It is a key component for achieving gas-liquid separation and directional diffusion.

[0030] The deionized water side flow path plate 303 is stacked on top of the carbon dioxide permeable membrane 304, and its material and processing technology are similar to those of the water sample side flow path plate 308. The deionized water side flow path plate 303 adopts a unique double-sided flow path design: on its side facing the carbon dioxide permeable membrane 304, a deionized water side inlet flow path 303a and a first-mode flow path 303b are etched; on its side facing away from the carbon dioxide permeable membrane 304 (i.e., towards the deionized water side pressure plate 302), a second-mode flow path 303c is formed. The first-mode flow path 303b includes a TC exchange detection branch parallel to the lower water sample TC flow path and an IC exchange detection branch parallel to the water sample IC flow path, both converging at the top through a NO connection hole. The second-mode flow path 303c also includes a TC detection branch and an IC detection branch, converging at an NC connection port. The deionized water side inlet flow path 303a has a deionized water inlet hole and a C connection hole penetrating the plate body at both ends. The deionized water side pressure plate 302, located at the top layer, is made of 316L stainless steel and has two deionized water connection holes, two conductivity measurement connection holes, and three solenoid valve connection holes for the installation and connection of the three-way solenoid valve 4. The deionized water side inlet interface 301 and deionized water side outlet interface 307 are installed on the corresponding deionized water connection holes, while the IC conductivity measurement inlet interface 305 and TC conductivity measurement inlet interface 306 are installed on the conductivity measurement connection holes. The deionized water side inlet interface 301, through the deionized water connection hole on the deionized water side pressure plate 302, is coaxially aligned with the deionized water inlet hole on the deionized water side flow path plate 303. Deionized water enters the deionized water side inlet flow path 303a and flows to the C connection hole at the end of the deionized water side inlet flow path 303a. The C connection hole is also connected to the common end (i.e., port C) of the three-way solenoid valve 4 through the corresponding deionized water connection hole of the upper deionized water side pressure plate 302.

[0031] The water sample side pressure plate 309, water sample side flow path plate 308, carbon dioxide permeable membrane 304, deionized water side flow path plate 303, and deionized water side pressure plate 302 are aligned sequentially from bottom to top and secured with external screws to form a sealed, stacked structure. The water sample flows in the flow path within the lower water sample side chamber, and the carbon dioxide released from the water sample permeates through the membrane 304 and diffuses into the deionized water flow path within the upper deionized water side chamber, thereby achieving the transfer and enrichment of carbon components.

[0032] The three-way solenoid valve 4 is a normally open (NO) / normally closed (NC) type solenoid valve, which is directly fastened to the deionized water side pressure plate 302 of the carbon dioxide exchange unit 3 through the mounting hole on its valve body. Its common end (i.e., port C) is connected to the deionized water side inlet flow path 303a through the C connection hole on the deionized water side flow path plate 303; its normally open end (i.e., port NO) is connected to the NO connection hole of the first flow path 303b through the corresponding holes on the deionized water side pressure plate 302 and the deionized water side flow path plate 303; and its normally closed end (i.e., port NC) is connected to the NC connection port of the second flow path 303c. By controlling the on and off of the control coil, the fluid channel can be switched instantaneously. It is the core control element for switching deionized water between the first flow path 303b and the second flow path 303c, thereby controlling the flow and stagnation of liquid in the exchange zone.

[0033] The conductivity measurement unit 5 includes two independent and high-precision conductivity sensor channels (i.e., the IC channel and the TC channel). Each channel includes a conductivity detection electrode, a temperature sensor, and corresponding signal conditioning circuitry. This unit receives carbon dioxide-enriched deionized water flowing in from the IC conductivity measurement inlet interface 305 and the TC conductivity measurement inlet interface 306 of the carbon dioxide exchange unit 3, measures its conductivity value in real time, performs temperature compensation, and outputs the accurate conductivity signal to the subsequent data processing system for calculating carbon concentration.

[0034] Water tank 6, as a storage container for deionized water, is usually made of inert polymer materials (such as PP, PFA). Its capacity is designed according to the continuous operating time of the instrument and is equipped with a liquid level indicator or sensor to ensure that the analyzer has a continuous and sufficient supply of ultrapure water.

[0035] The deionized water pump 7 provides the power for the circulation of deionized water throughout the system, and is typically a low-pulse, corrosion-resistant miniature pump. It draws deionized water from the water tank 6 and delivers it at a constant or controllable flow rate to the subsequent resin unit 8 and carbon dioxide exchange unit 3.

[0036] The resin unit 8 is filled with a high-performance mixed ion exchange resin and connected in series with the output of the deionized water pump 7. The residual trace ions in the deionized water flowing through this unit are adsorbed and removed by the resin, thereby reducing its conductivity to an extremely low level (typically reaching 18.2 MΩ·cm), minimizing the detection background value, and ensuring that the conductivity change caused by carbon dioxide dissolution can be clearly and accurately detected by the conductivity measurement unit 5.

[0037] See also Figures 1 to 6 The specific process of the flow-through membrane conductivity total organic carbon analysis method is as follows: Step S1: The water sample to be tested is split into an inorganic carbon measurement water sample and an initial total carbon measurement water sample. The initial total carbon measurement water sample is subjected to ultraviolet oxidation treatment of organic carbon to obtain a total carbon measurement water sample. The test water in the preset water tank is subjected to ion removal treatment to obtain deionized water.

[0038] When the analysis process begins, the water sample pump starts working, its input end immersed in the water sample to be tested, generating suction power to continuously draw the water sample into the system. The output end of the water sample pump is connected to a splitter, which mechanically divides the single water sample stream into two independent flow paths. One path is defined as the inorganic carbon measurement path; the water sample in this path (i.e., the inorganic carbon measurement sample) will be directly used for subsequent inorganic carbon measurements, therefore its composition must remain unchanged, especially the original dissolved carbon dioxide and other inorganic carbon components; the other path is defined as the initial total carbon measurement path. The water sample in the initial total carbon measurement path (i.e., the total carbon measurement sample) is immediately introduced into the ultraviolet oxidation chamber unit. The ultraviolet oxidation chamber unit is filled with high-intensity ultraviolet radiation, and its cavity is made of quartz material with an extended flow channel designed to increase the exposure time. As the water sample flows through this cavity, the energy of the ultraviolet photons breaks the chemical bonds of organic molecules in the water, completely oxidizing all organic carbon compounds, regardless of their molecular structure and complexity, into carbon dioxide. At this point, the water sample flowing out of the UV oxidation chamber unit is no longer in its "initial" state. All the carbon contained in it exists in the form of carbon dioxide. This carbon dioxide comes from the original inorganic carbon in the water sample and the carbon produced by the oxidation of organic carbon. Therefore, this water sample is called the total carbon measurement water sample.

[0039] Meanwhile, deionized water, which serves as the carrier for the detection process, is also prepared simultaneously. A deionized water pump draws ordinary pure water or deionized water (i.e., the test water) from the water tank and pumps it into a resin unit connected in series in the pipeline. The resin unit is filled with high-performance mixed ion exchange resin. As the water flows through, the resin adsorbs residual ions in the water, such as sodium ions, chloride ions, calcium ions, and magnesium ions, through ion exchange, reducing the water's conductivity to an extremely low background level, for example, 18.2 MΩ·cm, thus obtaining ultrapure deionized water suitable for high-sensitivity conductivity detection.

[0040] Step S2: Control the preset three-way solenoid valve to be in the preset first working state, so as to deliver the deionized water to the preset IC exchange detection branch and the preset TC exchange detection branch.

[0041] The control circuit keeps the three-way solenoid valve de-energized, i.e., in its first operating state. In this state, the internal passage of the solenoid valve connects the common terminal to the normally open terminal. Ultrapure deionized water from the resin unit enters the carbon dioxide exchange unit through the deionized water side inlet interface. It first passes through the connection hole on the deionized water side pressure plate to reach the deionized water inlet hole on the deionized water side flow path plate, and then flows into the deionized water side inlet flow path. The deionized water flows along this flow path, finally reaching the common terminal of the three-way solenoid valve through the C connection hole at the end of the flow path. Since the valve is in the first state, the deionized water then flows out from the normally open terminal of the valve, returns, and enters the NO connection hole on the deionized water side flow path plate. The NO connection hole is the starting point of the first flow path, which is also etched on the membrane-facing side of the flow path plate and clearly divided into two branches: one is the TC exchange detection branch, whose path is parallel to and directly opposite the water sample TC flow path on the sample side flow path plate below; the other is the IC exchange detection branch, parallel to and directly opposite the water sample IC flow path. After deionized water fills both branches, it flows out from their respective ports and enters the conductivity measurement unit through the corresponding conductivity measurement connection holes on the deionized water side plate, via the IC conductivity measurement inlet interface and the TC conductivity measurement inlet interface. During this stage, the two independent sensor channels within the conductivity measurement unit continuously monitor the conductivity of the flowing deionized water. Since the deionized water has not yet undergone gas exchange with any water sample, its conductivity value represents the system background. The purpose of this measurement is to obtain a clean reference signal to eliminate inherent background interference in subsequent calculations. For example, the conductivity measurement unit may record a background conductivity value of 0.055 μS / cm for both the IC and TC channels.

[0042] Step S3: The inorganic carbon measurement water sample and the total carbon measurement water sample are respectively transported to the preset water sample IC flow path and the preset water sample TC flow path, and the three-way solenoid valve is switched to the preset second working state to diffuse the carbon dioxide in the inorganic carbon measurement water sample and the total carbon measurement water sample into the deionized water in the IC exchange detection branch and the deionized water in the TC exchange detection branch, respectively.

[0043] The control circuit sends an electrical pulse signal to the three-way solenoid valve, energizing it and switching it to the second operating state. The valve's action alters the internal fluid path, connecting the common terminal to the normally closed terminal and disconnecting it from the normally open terminal. This flow path switching produces two effects: First, fresh deionized water continuously flowing from the deionized water inlet changes direction at the valve, flowing out from the normally closed terminal and entering the second flow path located on the back of the deionized water side flow path plate. This second flow path also includes a TC detection branch and an IC detection branch. Deionized water flows directly to the conductivity measurement unit through these two branches, ensuring that the sensor within the conductivity measurement unit is constantly flushed with flowing liquid throughout the entire exchange period. This completely avoids the ion dissolution contamination and signal drift on the sensor surface caused by liquid stillness in the traditional stop-flow method. Secondly, and more importantly, with the flow path switching, the portion of deionized water that was originally present in the first flow path—the TC exchange detection branch and the IC exchange detection branch—is completely intercepted and sealed within its respective flow path groove because both the inlet and outlet are cut off, entering a precisely controlled "pause" state. At this moment, the water sample side flow path begins to introduce the sample. The inorganic carbon measurement water sample enters the etched water sample IC flow path through the IC inlet interface on the water sample side, via the connection holes on the water sample side pressure plate and the water sample side flow path plate; the total carbon measurement water sample enters the parallel water sample TC flow path through the TC inlet interface on the water sample side. Above the two water sample flow paths, only an ultra-thin carbon dioxide permeable membrane separates them, and directly below is the paused exchange detection branch filled with deionized water. This membrane is made of Teflon or amorphous perfluorinated material, less than 40 micrometers thick, and has high selective permeability to carbon dioxide gas while effectively blocking liquid water and ions. Based on the principle of gas partial pressure diffusion, carbon dioxide molecules dissolved in the water sample spontaneously diffuse from the high-concentration water sample side through the membrane to the low-concentration deionized water side. Specifically, the inorganic carbon measurement water sample flowing through the IC flow path diffuses its inorganic carbon (carbon dioxide from the original water sample) into the deionized water in the paused IC exchange detection branch; the total carbon measurement water sample flowing through the TC flow path diffuses its total carbon (original inorganic carbon plus carbon dioxide generated by oxidation) into the deionized water in the paused TC exchange detection branch. This diffusion process lasts for a preset time, such as 30 seconds. The pause design provides sufficient and stable time for gas exchange, allowing carbon dioxide to dissolve to the maximum extent in the limited volume of deionized water, achieving efficient enrichment and overcoming the incomplete exchange defects that may occur due to the short contact time in continuous flow methods.

[0044] Step S4: Switch the three-way solenoid valve to the first working state, so as to transport the deionized water in the IC exchange detection branch to the preset conductivity measurement unit through the preset deionized water IC detection channel to obtain IC detection data, and transport the deionized water in the TC exchange detection branch to the conductivity measurement unit through the preset deionized water TC detection channel to obtain TC detection data.

[0045] After the preset exchange time, the system switches to the measurement phase. The control circuit disconnects the power to the three-way solenoid valve, restoring it to its first operating state. The valve reset reconnects the deionized water inlet flow path with the first flow path. Fresh, continuously flowing deionized water once again flows into the first flow path from the NO connection orifice. This flowing liquid acts like a piston, smoothly and sequentially pushing out the deionized water "plugs" that have become sufficiently enriched with carbon dioxide during the pause from their respective flow paths. The pushed-out liquid, carrying a significantly increased concentration of carbon dioxide, enters the conductivity measurement unit through the IC conductivity measurement inlet interface and the TC conductivity measurement inlet interface, respectively. Carbon dioxide dissolves in water to form carbonic acid, which dissociates to produce hydrogen ions and bicarbonate ions, thereby significantly increasing the conductivity of the water. The conductivity measurement unit captures this change in real time. Its IC channel measures the conductivity of the liquid from the IC exchange detection branch, reflecting the concentration of inorganic carbon in the water sample; its TC channel measures the conductivity of the liquid from the TC exchange detection branch, reflecting the concentration of total carbon in the water sample. A built-in temperature sensor in the measurement unit provides synchronous temperature compensation to eliminate the influence of temperature fluctuations on the conductivity readings, ensuring data accuracy. For example, after an exchange, the conductivity reading of the IC channel may rise to 0.255 μS / cm, while the reading of the TC channel may rise to 0.580 μS / cm.

[0046] Step S5: Calculate the total organic carbon concentration of the water sample to be tested based on the TC detection data and the IC detection data.

[0047] Finally, the integrated or external data processing system receives the temperature-compensated IC and TC detection data from the conductivity measurement unit. These raw conductivity signals first need to have the background conductivity values ​​of the corresponding channels measured in step S2 subtracted to obtain the conductivity increment purely caused by carbon dioxide dissolution. Since, under specific conditions, there is a definite linear or calibrable relationship between the conductivity increment and the carbon dioxide concentration (and consequently, the carbon concentration), the IC channel signal increment after background subtraction corresponds to the inorganic carbon concentration of the water sample, and the TC channel signal increment corresponds to the total carbon concentration of the water sample. The total organic carbon concentration is calculated based on the difference principle: the total organic carbon concentration equals the total carbon concentration minus the inorganic carbon concentration. This relationship can be directly mapped to the conductivity signal using the formula TOC concentration = K × (ΔK).TC -ΔK IC ) is calculated, where ΔK TC and ΔK IC These represent the conductivity increments of the TC and IC channels after background subtraction, respectively, and K is the system proportionality coefficient determined through standard solution calibration. After the processor performs this calculation, it displays the final total organic carbon concentration value of the water sample on the user interface or transmits it to the host computer, thus completing a complete and automated analysis cycle from sample introduction to result output.

[0048] like Figure 7 The diagram shown is a structural schematic of an electronic device provided in an embodiment of this application.

[0049] In a preferred embodiment of the present invention, the electronic device 7 may include, but is not limited to, a memory 71, at least one processor 72, and at least one communication bus 73.

[0050] Those skilled in the art should understand that Figure 7 The structure of the electronic device 7 shown does not constitute a limitation of the embodiments of the present invention. The electronic device 7 may also include more or fewer other hardware or software than shown, or different component arrangements.

[0051] In some embodiments, the electronic device 7 is a device capable of automatically performing numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes, but is not limited to, microprocessors, application-specific integrated circuits, programmable gate arrays, digital processors, and embedded devices.

[0052] It should be noted that the electronic device 7 is merely an example. Other existing or future electronic products that are suitable for this application should also be included within the scope of protection of this application and are incorporated herein by reference.

[0053] In some embodiments, the memory 71 stores a computer program that, when executed by the at least one processor 72, implements all or part of the steps in the flow-through membrane conductivity total organic carbon analysis method as described above. The memory 71 includes a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data. Further, the computer-readable storage medium may primarily include a program storage area and a data storage area, wherein the program storage area may store an operating system, at least one application program required for a function, etc.

[0054] In some embodiments, the at least one processor 72 is the control unit of the electronic device 7, connecting various components of the electronic device 7 via various interfaces and lines. It executes programs or modules stored in the memory 71 and calls data stored in the memory 71 to perform various functions and process data. For example, when the at least one processor 72 executes the computer program stored in the memory 71, it implements all or part of the steps of the flow-through membrane conductivity total organic carbon analysis method described in this embodiment; or it implements all or part of the functions of the flow-through membrane conductivity total organic carbon analyzer. The at least one processor 72 may be composed of integrated circuits, such as a single-packaged integrated circuit or multiple integrated circuits with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips.

[0055] In some embodiments, the at least one communication bus 73 is configured to enable communication between the memory 71 and the at least one processor 72, etc. Although not shown, the electronic device 7 may also include a power supply (e.g., a battery) to power the various components. Preferably, the power supply can be logically connected to the at least one processor 72 via a power management device, thereby enabling functions such as charging, discharging, and power consumption management. The power supply may also include one or more DC or AC power supplies, recharging devices, power fault detection circuits, power converters or inverters, power status indicators, and other arbitrary components. The electronic device 7 may also include various sensors, Bluetooth modules, Wi-Fi modules, etc., which will not be described in detail here.

[0056] The integrated unit implemented as a software functional module described above can be stored in a computer-readable storage medium. This software functional module, stored in a storage medium, includes several instructions to cause an electronic device (which may be a personal computer, electronic device, or network device, etc.) or processor to execute portions of the methods described in the various embodiments of this application.

[0057] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may be used in actual implementation.

[0058] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0059] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A flow-through cell type membrane conductivity total organic carbon analyzer, characterized in that, The analyzer includes: A water sample pump with its input end set in the water sample to be tested is used to extract the water sample to be tested to provide the flow power for the water sample to be tested, and to split the water sample to be tested into an inorganic carbon measurement flow path and a total carbon measurement flow path through the output end of the water sample pump. The ultraviolet oxidation chamber unit, which is set in the total carbon measurement flow path, is used to oxidize the organic carbon in the water sample to be tested into carbon dioxide. The carbon dioxide exchange unit for exchanging carbon dioxide in the water sample to be tested into deionized water is fixed on one side with a water sample-side IC inlet interface connected to the inorganic carbon measurement flow path, a water sample-side TC inlet interface connected to the output end of the ultraviolet oxidation chamber unit, a water sample-side IC outlet interface, and a water sample-side TC outlet interface. The other side of the carbon dioxide exchange unit is fixed with a deionized water-side inlet interface, an IC conductivity measurement inlet interface, a TC conductivity measurement inlet interface, and a deionized water-side outlet interface. A three-way solenoid valve fixed to the carbon dioxide exchange unit is used to control the flow path of deionized water in the carbon dioxide exchange unit. The input end is connected to the deionized water pump of the water tank, which is used to draw the deionized water in the water tank and provide the power for the flow of the deionized water; A resin unit disposed between the output end of the deionized water pump and the inlet interface of the deionized water is used to remove ions from the deionized water; and The conductivity measurement unit, connected to the IC conductivity measurement inlet interface and the TC conductivity measurement inlet interface, is used to measure the conductivity change data of the deionized water before and after absorbing carbon dioxide. The carbon dioxide exchange unit includes a water sample side chamber, a carbon dioxide permeable membrane, and a deionized water side chamber, which are stacked sequentially from bottom to top. The water sample side chamber includes a water sample side pressure plate and a water sample side flow path plate disposed between the water sample side pressure plate and the carbon dioxide permeation membrane. The water sample side pressure plate has two first water sample IC connection holes and two first water sample TC connection holes that penetrate from front to back. The side of the water sample side flow path plate facing the carbon dioxide permeation membrane is provided with independent water sample TC flow path and water sample IC flow path. The first and last sides of the water sample TC flow path have second water sample TC connection holes that penetrate from front to back. The first and last sides of the water sample IC flow path have second water sample IC connection holes that penetrate from front to back. The deionized water side chamber includes a deionized water side pressure plate and a deionized water side flow path plate disposed between the deionized water side pressure plate and the carbon dioxide permeation membrane. The deionized water side pressure plate has two deionized water connection holes penetrating its front and rear, two conductivity measurement connection holes penetrating its front and rear, and three solenoid valve connection holes penetrating its front and rear, located below the three-way solenoid valve. The side of the deionized water side flow path plate facing the carbon dioxide permeation membrane has independent deionized water inlet flow paths and a first-mode flow path. The side of the deionized water side flow path plate facing the deionized water side pressure plate has a second-mode flow path. The flow path includes a deionized water inlet hole extending through the front and back on one side, and a C-connection hole extending through the front and back on the other side. The first flow path includes a NO connection hole extending through the front and back at the top, a TC exchange detection branch connecting the NO connection hole and parallel to the TC flow path of the water sample, and an IC exchange detection branch connecting the NO connection hole and parallel to the IC flow path of the water sample. The second flow path includes an NC connection port at the top, a TC detection branch connecting the NC connection port, and an IC detection branch connecting the NC connection port. The deionized water inlet interface and the deionized water outlet interface are respectively embedded in the deionized water connection hole. The deionized water inlet interface is coaxially connected to the deionized water inlet hole through the deionized water connection hole to form a deionized water inlet transmission channel. The three-way solenoid valve is connected to the C connection hole and the NO connection hole through the solenoid valve connection hole to form an exchange detection channel. The three-way solenoid valve is connected to the NC connection port through the solenoid valve connection hole to form a deionized water detection channel. The IC conductivity measurement inlet interface is connected to the bottom of the IC exchange detection branch through a conductivity measurement connection hole to form an IC exchange detection channel, and is also connected to the bottom of the IC detection branch to form a deionized water IC detection channel; The TC conductivity measurement inlet interface is connected to the bottom of the TC exchange detection branch through another conductivity measurement connection hole to form a TC exchange detection channel, and is also connected to the bottom of the TC detection branch to form a deionized water TC detection channel.

2. The flow-through cell membrane conductivity total organic carbon analyzer according to claim 1, characterized in that, The water sample side IC inlet interface and the water sample side IC outlet interface are respectively connected to the second water sample IC connection holes on both sides of the water sample IC flow path through the first water sample IC connection hole, forming a water sample IC transmission channel; The water sample side TC inlet interface and the water sample side TC outlet interface are respectively connected coaxially to the second water sample TC connection holes on both sides of the water sample TC flow path through the first water sample TC connection hole, forming a water sample TC transmission channel.

3. The flow-through cell membrane conductivity total organic carbon analyzer according to claim 1, characterized in that, The water sample TC flow path, the TC exchange detection branch, the water sample IC flow path, and the IC exchange detection branch all adopt a U-shaped structure or a serpentine structure.

4. The flow-through cell membrane conductivity total organic carbon analyzer according to claim 1, characterized in that, The carbon dioxide permeation membrane is made of Teflon film or amorphous perfluorinated film.

5. The flow-through cell membrane conductivity total organic carbon analyzer according to claim 1, characterized in that, The ultraviolet oxidation chamber unit includes an ultraviolet oxidation chamber and an ultraviolet lamp built into the ultraviolet oxidation chamber.

6. A method for analyzing total organic carbon using a flow-through membrane conductivity analyzer, applied to the flow-through membrane conductivity analyzer for total organic carbon as described in any one of claims 1 to 5, characterized in that, The method includes: The water sample to be tested is split into an inorganic carbon measurement water sample and an initial total carbon measurement water sample. The initial total carbon measurement water sample is subjected to ultraviolet oxidation treatment of organic carbon to obtain a total carbon measurement water sample. The test water in the preset water tank is subjected to ion removal treatment to obtain deionized water. The preset three-way solenoid valve is controlled to be in a preset first working state so as to deliver the deionized water to the preset IC exchange detection branch and the preset TC exchange detection branch. The inorganic carbon measurement water sample and the total carbon measurement water sample are respectively transported to the preset water sample IC flow path and the preset water sample TC flow path, and the three-way solenoid valve is switched to the preset second working state to diffuse the carbon dioxide in the inorganic carbon measurement water sample and the total carbon measurement water sample into the deionized water in the IC exchange detection branch and the deionized water in the TC exchange detection branch, respectively. The three-way solenoid valve is switched to the first working state so that the deionized water in the IC exchange detection branch is delivered to the preset conductivity measurement unit through the preset deionized water IC detection channel to obtain IC detection data, and the deionized water in the TC exchange detection branch is delivered to the conductivity measurement unit through the preset deionized water TC detection channel to obtain TC detection data. The total organic carbon concentration of the water sample to be tested is calculated based on the TC detection data and the IC detection data.

7. An electronic device, characterized in that, The electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the flow-through membrane conductivity total organic carbon analysis method according to claim 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the flow-through cell membrane conductivity total organic carbon analysis method according to claim 6.

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