Flow injection instrument for in-situ rapid determination of volatile phenol in water based on chemiluminescence principle

Abstract

The invention discloses a flow injection instrument for in-situ rapid determination of volatile phenol in water based on a chemiluminescence principle, and belongs to the field of water quality detection. The instrument comprises a pretreatment device (a filter, a first peristaltic pump and a distiller) and is used for separating and purifying a sample; and the light-emitting detection device (a second peristaltic pump, a six-way valve, a quantitative loop, a flow cell, a light detector and the like) is used for generating and collecting light-emitting signals, a computer terminal and a power supply. A volatile phenol water sample and a luminescent system required by the invention are respectively conveyed by corresponding peristaltic pumps, are adjusted by a six-way valve, enter a flow cell, and are mixed for chemical reaction. The optical detector converts an optical signal generated in the flow cell into an electric signal and amplifies the electric signal, and then transmits the signal to a computer terminal, so that the chemiluminescence quenching efficiency (CLQC) is obtained on the terminal, and finally, the concentration of volatile phenol in a sample (based on phenol) is quantified according to the quantitative relationship between the CLQC and the phenol concentration established by a phenol external standard method. And conditions are provided for in-situ rapid detection of volatile phenol in water.

Description

Technical Field

[0001] The present invention belongs to the technical field of water quality detection, and in particular relates to a flow injection instrument for in-situ rapid determination of volatile phenols in water based on the principle of chemiluminescence. The flow injection instrument can be used for rapid determination of volatile phenol content in scenes such as water plants and rivers, providing data support for timely adjustment of water plant process parameters and water quality detection work of relevant departments, ensuring efficient operation of water plants, optimizing operating procedures, and improving the efficiency of water quality detection. Background Art

[0002] With the acceleration of industrialization, phenolic compounds are widely used in production and daily life. Due to their toxicity and volatility, volatile phenols pose a direct threat to human health and environmental safety, making them important indicators in environmental monitoring. Current methods for quantifying volatile phenol content in water primarily include chromatography (such as solid-phase extraction / high-performance liquid chromatography and liquid-liquid extraction / gas chromatography) and colorimetry (such as the 4-aminoantipyrine method). However, these methods generally suffer from limitations such as high cost, cumbersome operation, and long detection times. Furthermore, some methods (such as the 4-aminoantipyrine method) have detection blind spots (inability to detect volatile phenols of specific structures). These limitations make it difficult for existing technologies to meet the demand for in-situ, rapid detection of volatile phenols in water and to support the timely optimization of water plant process parameters.

[0003] As a simple, rapid, and efficient analytical method, chemiluminescence has been applied to the detection of volatile phenols in previous studies, usually based on the quenching effect of volatile phenols on chemiluminescence reactions. However, existing chemiluminescence methods for detecting volatile phenols are still mainly limited to intermittent detection under laboratory conditions. The collection, transportation, and dilution of phenol-containing water samples are time-consuming and may introduce errors, making it impossible to quickly obtain true on-site detection results. Due to the lack of suitable detection instruments, it is difficult to achieve in-situ continuous or rapid detection of volatile phenols in actual scenarios such as water plants and rivers.

[0004] Based on this, the existing technology urgently needs to develop an instrument based on the chemiluminescence principle that can realize the in-situ rapid determination of volatile phenols in water in actual scenarios. Summary of the Invention

[0005] The present invention aims to address the technical issue of existing methods for detecting volatile phenols in water, which hinder rapid in-situ measurement. By providing a flow injection instrument based on chemiluminescence for rapid in-situ measurement of volatile phenols in water, the instrument enables rapid on-site measurement of volatile phenols in water samples across a variety of practical scenarios. This instrument boasts portability, high sensitivity, and accuracy, providing a convenient, rapid, and efficient method for environmental monitoring and adjusting process parameters in water plants, demonstrating its practicality and potential for widespread adoption.

[0006] The specific technical solution for achieving the purpose of the present invention is: A flow injection instrument for rapid in-situ determination of volatile phenols in water based on the chemiluminescence principle, comprising: A pretreatment device, used for distilling and purifying the sample to be tested, comprising a filter, a first peristaltic pump and a distiller, wherein the filter, the first peristaltic pump and the distiller are sequentially connected by pipelines; A luminescence detection device is integrated into the housing to ensure strict light-proof conditions, provides a place for the pretreated water sample and the luminescence system to undergo a chemiluminescence reaction, and detects changes in the chemiluminescence signal. The device includes a second peristaltic pump, a six-way valve, a quantitative loop, a circulation cell, and a light detector. The six-way valve is connected to the quantitative loop, the distiller, the second peristaltic pump, the circulation cell, and the light detector through pipelines. A computer terminal, used for receiving chemiluminescent signal data and performing data processing and quantification; connected to the light detector via a circuit; a power supply for supplying power to the first peristaltic pump, the distiller, the second peristaltic pump, the light detector, and the computer terminal; in: The filter is used to filter out suspended particulate matter that may be present in the in-situ phenol-containing water sample to prevent clogging of the pipeline; the first peristaltic pump is used to control the inflow of phosphoric acid solution and condensed water required for the collection and distillation of the phenol-containing water sample, wherein the phosphoric acid solution is prepared by mixing 85% concentrated phosphoric acid and distilled water in a ratio of 1:9; the second peristaltic pump is used to transport a luminescence system, which includes a mixed reducing carrier liquid of ferrous iron, naproxen, and tartaric acid, and a periodate oxidizing solution. The luminescence system enters the flow cell for a mixed reaction to generate a chemiluminescence signal; the photodetector converts the chemiluminescence signal into an electrical signal and amplifies it, collects the amplified signal and transmits it to the computer terminal, presenting a stable chemiluminescence curve; the pretreated volatile phenol water sample is regulated by the six-way valve and enters the flow cell, where a quenching reaction occurs to reduce the chemiluminescence signal; the photodetector captures the reduced signal and transmits it to the computer terminal, and the chemiluminescence quenching efficiency (CLQC) is calculated based on the degree of reduction in the chemiluminescence signal, and quantification of volatile phenol in water is achieved based on the external standard curve.

[0007] Furthermore, the distiller has a preset temperature of 100-160° C. and is equipped with a degassing component.

[0008] Furthermore, the flow rates of the corresponding flow paths of the first peristaltic pump and the second peristaltic pump are both 1-20 mL·min -1 .

[0009] Furthermore, the inlet of the circulation pool is Y-shaped and the flow path is S-shaped, and a waste liquid outlet is provided at the end.

[0010] Furthermore, the operating voltage of the light detector is 100-1000 V.

[0011] Furthermore, the concentration of ferrous iron in the luminescent system is 10-2000 μM, the concentration of naproxen is 10-200 μM, the concentration of tartaric acid is 10-2000 μM, the concentration of periodate is 10-2000 μM, and the pH of the luminescent system is 1.0-6.0.

[0012] Furthermore, the mixed reducing carrier liquid and the pretreated water sample are introduced through the six-way valve, and the periodate solution directly enters the circulation cell.

[0013] Furthermore, the chemiluminescence generation process of the luminescence system is as follows: ferrous iron in the luminescence system reacts with periodate to generate Fe(IV) oxide species, which in turn oxidizes the probe substance naproxen; during the transition of the oxidation product of naproxen from an excited state to a ground state, energy is released in the form of light radiation, generating stable chemiluminescence; the tartaric acid can change the coordination environment, thereby enhancing the chemiluminescence process; The chemiluminescence intensity of the luminescence system is affected by the quenching effect of volatile phenols in the pretreated water sample. Specifically, the volatile phenols in the pretreated water sample compete with naproxen to consume Fe(IV) oxidation species, resulting in a decrease in naproxen's oxidation products, thereby reducing the chemiluminescence signal. Different concentrations of volatile phenols will present quenching peaks of different intensities on the computer terminal. The content of volatile phenols in the water is quantified by detecting and analyzing the changes in the chemiluminescence intensity.

[0014] An application of the above-mentioned flow injection instrument in the in-situ rapid determination of volatile phenol content in water plants and rivers.

[0015] The present invention can quickly measure the volatile phenol content in actual scenes such as water plants and rivers in situ, reflect the concentration of volatile phenol in real time through the changes in optical signals, and use the phenol concentration as a unified measurement.

[0016] The beneficial effects brought about by the technical solution of the present invention are: (1) The instrument encapsulates components such as the peristaltic pump, distiller, and light detector in a housing to achieve instrument integration, improve the portability of the detection equipment, and provide conditions for the in-situ rapid detection of volatile phenols in water.

[0017] (2) The instrument performs distillation pretreatment on volatile phenol water samples, which helps to reduce the interference of other factors such as suspended matter, color, dissolved organic matter, etc. on the detection results in actual scenarios and improve the accuracy of volatile phenol detection.

[0018] (3) The flow cell of the instrument adopts a Y-shaped inlet and S-shaped flow path design. The Y-shaped inlet allows the reactants to be mixed instantaneously before entering the detection area, avoiding premature mixing of the reactants and resulting in attenuation of the luminescence signal; the S-shaped flow path increases the residence time of the mixed solution in the detector, improving detection sensitivity and accuracy, and is suitable for fast luminescence systems.

[0019] (4) The instrument automates the three steps of sample pretreatment, chemiluminescence detection, and data analysis, simplifies the operation process, realizes automated sampling, detection, and data analysis, and improves the convenience and efficiency of volatile phenol detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is the appearance diagram of the present invention; Figure 2 for Figure 1 A top cross-sectional view of Figure 3 for Figure 2 aa-direction cross-sectional view; Figure 4 for Figure 2 bb cross-section; Figure 5 Schematic diagram of two working modes of the six-way valve in the present invention; Figure 6 is a schematic diagram of the workflow of the present invention according to an exemplary embodiment; Figure 7 is a relationship diagram between the CLQC established by the present invention using phenol as an external standard and the concentration of volatile phenols; Figure 8 is a comparison chart showing the concentration of volatile phenols detected by the present invention and the concentration detected by the 4-aminoantipyrine method according to an exemplary embodiment; In the figure: 1-filter; 2-first peristaltic pump; 3-mobile power supply; 4-distillation device; 5-quantitative loop; 6-six-way valve; 7-second peristaltic pump; 8-photodetector; 9-circulation cell; 10-photodetector housing; 11-computer terminal; 12-instrument housing. DETAILED DESCRIPTION

[0021] In order to better understand the content of the present invention, the present invention is further described below through an exemplary embodiment and the accompanying drawings, but the embodiment does not limit the protection scope of the present invention.

[0022] Unless otherwise specified, the numbers in the drawings always represent specific elements. The operation modes described in the following embodiments do not represent all operation modes consistent with this application.

[0023] Figure 1 The figure is an external view of a flow injection instrument for rapid in-situ determination of volatile phenols in water based on the chemiluminescence principle according to an exemplary embodiment; Figure 2 for Figure 1 A top cross-sectional view of Figure 3 for Figure 2 b-b' cross-sectional view; Figure 4 for Figure 2The instrument includes a filter 1, a first peristaltic pump 2, a mobile power supply 3, a distiller 4, a quantitative ring 5, a six-way valve 6, a second peristaltic pump 7, a light detector 8, a circulation pool 9, a light detector housing 10, a computer terminal 11 and an instrument housing 12. The computer terminal 11 is embedded in the instrument housing, and the remaining components are integrated inside the instrument housing 12. The instrument housing has reserved pipe inlets and outlets for connecting external sample lines, waste liquid lines and reagent bottles. Among them, the pretreatment device includes a filter, a first peristaltic pump, and a distiller. This part contains three inlet pipes (for inputting in-situ phenol-containing water samples, condensed water and phosphoric acid solution required for distillation) and two outflow pipes (for outputting pretreated water samples and distilled wastewater). The filter 1 is installed at the front end of the in-situ water sample pipeline, and the first peristaltic pump 2 provides transmission power. When extracting actual water samples in situ, the filter 1 first removes any suspended particulate matter to prevent pipeline clogging. The distiller 4 then separates and purifies the volatile phenols in the in-situ water sample. The condensed pretreated water sample enters the subsequent luminescence detection device through a pipeline, and the distilled waste liquid is discharged through a waste liquid pipeline. The luminescence detection device includes a second peristaltic pump 7, a six-way valve 6, a quantitative loop 5, a photodetector 8, and a circulation cell 9. To ensure the accuracy of chemiluminescence detection, the luminescence detection device must maintain strict light-proof conditions. Therefore, the photodetector 8 and circulation cell 9 are additionally enclosed in a housing 10. The second peristaltic pump 7 and six-way valve 6 are fixed to the photodetector housing 10. This section includes three inlet pipes (for inputting the required ferrous iron / naproxen / tartaric acid mixed carrier liquid, periodate solution, and pretreated water sample) and two outlet pipes (for outputting sampling waste liquid and test waste liquid). The second peristaltic pump 7 provides transmission power. It should be noted that the ferrous iron / naproxen / tartaric acid mixed carrier liquid and the pretreated water sample are connected to the six-way valve, while the periodate solution is not. The pretreated water sample flows into position 1 of the six-way valve; the ferrous iron / naproxen / tartaric acid mixed carrier liquid flows into position 4 and enters the flow cell through position 3; the quantitative loop is connected to positions 2 and 5 of the six-way valve; and the sample waste liquid flows out through position 6. The ferrous iron / naproxen / tartaric acid mixed carrier liquid and the periodate solution mix at the Y-shaped inlet of the flow cell, where a chemiluminescent reaction occurs. The signal is then captured and amplified by the photodetector. During the sampling time, the pretreated water sample continuously fills the quantitative loop until the injection program is initiated, at which point it is injected into the flow cell for a quenching reaction. The signal is transmitted via a circuit to a computer terminal, and the change in chemiluminescent intensity is calculated to determine the volatile phenol concentration (measured in phenol) of the corresponding water sample.

[0024] Specifically, if Figure 5 As shown, the six-way valve 6 in the luminescence detection device has two operating modes to control the injection of pretreated water samples and the occurrence of quenching reaction. Mode 1 is called sampling mode, and the corresponding six-way valve position is defined as Figure 5A sampling position. In the above mode, the pre-treated water sample is continuously injected and fills the quantitative loop, and the excess volatile phenol is continuously discharged to the waste liquid through the pipeline. After a certain period of time, the injection program set by the computer is started, and the luminescence detection device will enter mode 2, called injection mode. The position of the six-way valve will switch, and the corresponding six-way valve position is defined as Figure 5 Injection position B. In this mode, the mixed carrier liquid of ferrous iron / naproxen / tartaric acid is connected to the pipeline where the quantitative loop is located, and the volatile phenol sample in the quantitative loop is injected into the flow cell as a plug flow, thereby generating a quenching reaction.

[0025] Specifically, the duration and switching time of the sampling mode and the injection mode can be defined by the computer program "BPLC Luminescence Test Analysis System".

[0026] Specifically, to maximize the portability of the instrument, a tablet computer is used as the computer terminal 11. All power-consuming components are powered by the power supply, and the peristaltic pump provides transmission power during the flow injection process.

[0027] Figure 6 FIG. 1 is a schematic diagram of a flow injection instrument for rapid in-situ determination of volatile phenols in water based on the chemiluminescence principle according to an exemplary embodiment. Figure 6 As shown, solution one is a mixed reducing carrier liquid of ferrous iron / naproxen / tartaric acid; solution two is a periodate solution; and solution three is a phosphoric acid solution required for distillation.

[0028] The specific working process of the present invention is as follows: first, a phenol-containing water sample and phosphoric acid and condensed water required for distillation are extracted in situ by a first peristaltic pump, suspended particulate matter that may be present in the in-situ water sample is filtered out by a filter, and the volatile phenol in the in-situ water sample is separated and purified in a distiller preheated to a specified temperature, and automatically degassed after condensation. In the sampling mode, the six-way valve is in position A, the pretreated water sample continuously fills the quantitative loop through the six-way valve, and the excess pretreated water sample is discharged through the pipeline. At the same time, a mixed carrier liquid of ferrous iron / naproxen / tartaric acid is mixed with a periodate solution in a circulation pool through a second peristaltic pump to generate a stable chemiluminescent signal. The light signal is captured by a light detector, converted into an electrical signal and amplified, presenting a stable luminescence curve on a computer terminal. After the preset time is reached, the computer injection program is started, the six-way valve is switched to position B, and the carrier liquid pushes the pretreated water sample in the quantitative loop into the circulation pool. Volatile phenols compete with naproxen for the Fe(IV) oxide species, quenching the chemiluminescent signal. This results in a quenching peak of varying intensity on the computer terminal, depending on the concentration of the volatile phenol. The actual concentration of volatile phenols in the water sample (measured as phenol) can be determined using an external standard curve for phenol quenching.

[0029] Specifically, the phenol external standard method was used to draw Figure 7The standard curve shown, the obtained R 2 = 0.993, indicating a good linear relationship between CLQC and phenol concentration. Based on the standard curve, the limit of detection (LOD) of the instrument was 3.55 μg / L, and the limit of quantification (LOQ) was 11.83 μg / L.

[0030] In one embodiment, volatile phenols in coking wastewater were detected by continuously collecting the original ammonia water of the first and second phase solvents of a coking wastewater plant, namely water sample 1, the wastewater of the first and second phase adjustment tank, namely water sample 2, and the wastewater of the first and second phases, namely water sample 3. The suspended particles that may be present were filtered out by a filter, and the water was distilled and purified by a pretreatment device before entering the luminescence detection device. The detection results of this instrument were compared with the volatile phenol concentration of the water sample measured by the 4-aminoantipyrine method. Figure 8 As shown, the volatile phenol concentrations measured by the present invention are highly consistent with those measured by the 4-aminoantipyrine method, with relative errors within acceptable ranges (e.g., the relative error for the original ammonia solution used as the solvent for Phases I and II is 2.3%, the relative error for the wastewater from the adjustment tank for Phases I and II is 2.9%, and the relative error for the external drainage from Phases I and II is 8.5%). This demonstrates that the present invention can accurately measure the volatile phenol content in actual water samples.

[0031] The present application is not limited to the above-mentioned operation mode and the contents shown in the accompanying drawings, and appropriate modifications can be made within a reasonable range without departing from the spirit and scope of the present invention. Any equivalent replacement or simple change made by those skilled in the art based on the prior art of the present invention using the technical solution of the present invention falls within the scope of protection of the present invention. The present application is intended to protect any modification, use and technical means of the instrument, which all follow the general principles of the present application and include information not disclosed in the present application.

Claims

1. A flow injection instrument for rapid in-situ determination of volatile phenols in water based on the principle of chemiluminescence, characterized in that: include: A pretreatment device, used for distilling and purifying the sample to be tested, comprising a filter, a first peristaltic pump and a distiller, wherein the filter, the first peristaltic pump and the distiller are sequentially connected by pipelines; A luminescence detection device provides a place for the pretreated water sample and the luminescence system to undergo a chemiluminescence reaction and detects changes in the chemiluminescence signal, including a second peristaltic pump, a six-way valve, a quantitative loop, a circulation cell, and a light detector. The six-way valve is connected to the quantitative loop, the distiller, the second peristaltic pump, the circulation cell, and the light detector through pipelines. A computer terminal, used for receiving chemiluminescent signal data and performing data processing and quantification; connected to the light detector via a circuit; a power supply for supplying power to the first peristaltic pump, the distiller, the second peristaltic pump, the light detector, and the computer terminal; in: The filter is used to filter out suspended particulate matter that may exist in the in-situ phenol-containing water sample to prevent clogging of the pipeline; the first peristaltic pump is used to control the collection and distillation of the phenol-containing water sample. The phosphoric acid solution is prepared by mixing 85% concentrated phosphoric acid and distilled water in a ratio of 1:9; the second peristaltic pump is used to transport the luminescence system, which includes a mixed reducing carrier liquid of ferrous iron, naproxen and tartaric acid and a periodate oxidation solution. The luminescence system enters the circulation pool for mixed reaction to generate a chemiluminescence signal; the light detector converts the chemiluminescence signal into an electrical signal and amplifies and transmits it to the computer terminal, presenting a stable chemiluminescence curve; the pretreated volatile phenol water sample is regulated by the six-way valve to enter the circulation pool, where a quenching reaction occurs to reduce the chemiluminescence signal; the light detector captures the reduced signal and transmits it to the computer terminal, calculates the chemiluminescence quenching efficiency based on the degree of reduction of the chemiluminescence signal, and realizes the quantification of volatile phenol in water according to the external standard curve.

2. The flow injection apparatus according to claim 1, characterized in that The distiller has a preset temperature of 100-160°C and is equipped with a degassing component.

3. The flow injection apparatus according to claim 1, characterized in that The flow rates of the corresponding flow paths of the first peristaltic pump and the second peristaltic pump are both 1-20 mL·min -1 .

4. The flow injection apparatus according to claim 1, characterized in that The inlet of the circulation pool is Y-shaped and the flow path is S-shaped, and a waste liquid outlet is provided at the end.

5. The flow injection apparatus according to claim 1, characterized in that The operating voltage of the light detector is 100-1000 V.

6. The flow injection apparatus according to claim 1, characterized in that In the luminescent system, the concentration of ferrous iron is 10-2000 μM, the concentration of naproxen is 10-200 μM, the concentration of tartaric acid is 10-2000 μM, the concentration of periodate is 10-2000 μM, and the pH of the luminescent system is 1.0-6.

0.

7. The flow injection apparatus according to claim 1, characterized in that The mixed reducing carrier liquid and the pretreated water sample are introduced through the six-way valve, and the periodate solution directly enters the circulation pool.

8. The flow injection apparatus according to claim 1 or 6, characterized in that: The chemiluminescence generation process of the luminescence system is as follows: ferrous iron in the luminescence system reacts with periodate to generate Fe(IV) oxide species, which in turn oxidizes the probe substance naproxen. During the transition of the oxidation product of naproxen from an excited state to a ground state, energy is released in the form of light radiation, thereby generating stable chemiluminescence; The tartaric acid can change the coordination environment and thus enhance the chemiluminescence process; The chemiluminescence intensity of the luminescence system is affected by the quenching effect of volatile phenols in the pretreated water sample. Specifically, the volatile phenols in the pretreated water sample compete with naproxen to consume Fe(IV) oxidation species, resulting in a decrease in naproxen's oxidation products, thereby reducing the chemiluminescence signal. Different concentrations of volatile phenols will present quenching peaks of different intensities on the computer terminal. The content of volatile phenols in the water is quantified by detecting and analyzing the changes in the chemiluminescence intensity.

9. Use of the flow injection instrument according to claim 1 for in-situ rapid determination of volatile phenol content in water plants and rivers.

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