A volatile matter enrichment device and its application, a Raman spectroscopy monitoring device, and a medical monitoring device

Abstract

A volatile substance enrichment device includes a sample evaporation chamber, a piston cylinder, and a volatile substance enrichment tube. An electric heating evaporation box is arranged in the horizontal tube of the sample evaporation chamber. The air inlet of the horizontal tube of the sample evaporation chamber is connected to a portable air pump, and the air outlet is communicated with the side wall of the piston cylinder. A piston is arranged in the piston cylinder, and the top of the piston cylinder is communicated with the bottom of the volatile substance enrichment tube. A filling module I, a support, and a filling module II are arranged in the sample evaporation chamber. A Venturi structure is formed among the filling module I, the filling module II, and the electric heating evaporation box. A waterproof semi-permeable membrane and a metal nanoparticle composite film are sequentially arranged in the volatile substance enrichment tube from bottom to top, and an absorbent accommodation cavity is formed between the two. The absorbent accommodation cavity is filled with a volatile substance absorbent liquid. A Raman spectroscopy monitoring device and a medical monitoring device have the above-mentioned volatile substance enrichment device. The device has a simple structure, small volume, reasonable design, and is convenient to be carried to the site for real-time detection, and is widely used in the fields of environment, food, and medical treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of analytical detection, and particularly relates to a volatile enrichment device and its application, a Raman spectroscopy monitoring device, and a medical monitoring device. Background Art

[0002] Surface-enhanced Raman spectroscopy (SERS) is a new detection technology developed in recent years. It has the characteristics of fast detection speed, high sensitivity, and portable instrument, and has been applied in the fields of environmental analysis, food safety, pesticide residues, public safety and health, and medical detection. At present, in the on-site analysis and detection of these fields, the sample volume is large and the timeliness is strong, and the requirements for detection technology are faster, simpler, and high-throughput. However, in the process of applying SERS to the analysis of complex systems, how to eliminate the interference of sample matrix has become an urgent problem to be solved in the practical application of SERS, because SERS enhancement particles are prone to agglomeration or other physical and chemical changes in a complex matrix environment, resulting in a significant decrease in the sensitivity and accuracy of SERS.

[0003] The current sample pretreatment technologies mainly include molecular imprinting, solid-phase extraction, liquid-liquid extraction, and magnetic material functionalization, etc. The development and application of these pretreatment technologies have improved the accuracy of SERS detection. However, these pretreatment processes are relatively complex and time-consuming. In addition, the devices required for these pretreatment methods are large in volume and not convenient to carry to the site for on-site real-time rapid detection and analysis combined with SERS. Summary of the Invention

[0004] The purpose of the present invention is to provide a volatile enrichment device and its application, a Raman spectroscopy monitoring device, and a medical monitoring device, which have a simple structure, small volume, reasonable design, and are convenient to carry to the site for real-time detection.

[0005] To achieve the above purpose, a volatile enrichment device includes a sample evaporation chamber in an inverted "T" shape, a piston cylinder, and a volatile enrichment tube. An electric heating evaporation box for accommodating a sample to be measured is arranged in the horizontal tube of the sample evaporation chamber. The electric heating evaporation box is connected to a power supply. One end of the vertical tube of the sample evaporation chamber is provided with a sample inlet, and a sealing cover is provided in a supporting manner on the sample inlet. A placement opening for the electric heating evaporation box is opened on the wall of the horizontal tube of the sample evaporation chamber. One end of the horizontal tube of the sample evaporation chamber is an air inlet, and the other end is an air outlet. The air inlet is connected to a portable air pump through a transmission tube, and the air outlet is communicated with the side wall of the piston cylinder through a transmission tube. A piston that can move up and down is arranged in the piston cylinder. The top of the piston cylinder is communicated with the bottom of the volatile enrichment tube through a transmission tube, and one-way valves are provided on all the transmission tubes;

[0006] At the bottom inside the horizontal tube of the sample evaporation chamber, a filling module I is provided near the air inlet, and a filling module II is provided near the air outlet. The electric heating evaporation box is arranged between the filling module I and the filling module II. The filling height of the filling module I, the filling height of the filling module II, and the height of the electric heating evaporation box decrease in sequence. A Venturi structure is formed among the filling module I, the electric heating evaporation box, and the filling module II. When the gas moves in the sample evaporation chamber, a negative pressure area is formed in the Venturi structure area.

[0007] Inside the volatile matter enrichment tube, a waterproof semi-permeable membrane and a metal nanoparticle composite film are sequentially arranged from bottom to top. An absorbent accommodation cavity is formed between the waterproof semi-permeable membrane and the metal nanoparticle composite film. The absorbent accommodation cavity is filled with a volatile matter absorbent or a standard solution of the substance to be analyzed.

[0008] Preferably, the metal nanoparticle composite film is an AgNPs@CA composite film. The preparation method of the AgNPs@CA composite film is as follows: using silver nitrate as a raw material, hydrazine as a reducing agent, using an ethanol / water binary solution as a reaction medium, and using cellulose acetate as a matrix, and preparing it by an in-situ reduction method.

[0009] Further, the absorbent contains a derivatization reagent for the substance to be measured.

[0010] Further, the electric heating evaporation box includes a container for containing the sample to be measured and a heating sheet arranged around the container. The heating sheet is provided with an annularly arranged electric heating wire and coated with a silica gel layer.

[0011] Further, a flow control valve is provided on each of the gas transmission pipes.

[0012] Further, the power supply is a rechargeable power supply and is provided with a controllable transmission voltage switch, and the output voltage of the power supply is below 12V.

[0013] Preferably, the portable air pump is a micro air pump, and the air inlet of the micro air pump is connected to a nitrogen gas cylinder.

[0014] The present invention also provides an application of the volatile matter enrichment device, including the following steps:

[0015] a. Pretreatment of the sample: Take the sample to be measured and prepare a series of standard solutions of the analyte with different concentrations.

[0016] b. Preparation of the absorbent or the absorbent and the derivatization reagent: When the analyte does not have a surface-enhanced Raman spectral response, a derivatization reagent needs to be added to the absorbent to cause the analyte to undergo a derivatization reaction to be converted into a substance with a strong surface-enhanced Raman response.

[0017] c. Vaporization and enrichment treatment of samples and standard solutions: Turn on the power supply, seal it through the sealing cover, adjust the power supply voltage, and use the heating sheet around the electric heating evaporation box to heat the samples in the box. Turn on the portable air pump to provide a constant purge gas flow rate to the sample evaporation chamber, and purge the volatile substances to be trapped into the piston cylinder. When the piston moves upward, the internal pressure in the piston cylinder increases, and the samples and standard solutions pass through the sample evaporation chamber to separate the analyte from the matrix. The volatilized gas passes through the waterproof and breathable membrane and is absorbed and enriched by the absorbent solution in the absorbent solution chamber. After the analyte in the samples and standard solutions is completely absorbed, stop heating;

[0018] d. SERS detection: Place the flexible SERS substrate semi-transparent optical film above the metal nanoparticle composite film and wait for 5 minutes, then use the handheld Raman spectrometer to detect the optical film;

[0019] e. Plotting of the standard curve: Take a series of standard solutions with different concentrations in the electric heating evaporation box of the volatile substance enrichment device respectively. After being processed by step c and step d, read the peak area at the characteristic Raman shift of the analyte, and plot the standard curve of the peak area - analyte content at the characteristic Raman shift;

[0020] f. Determination of sample concentration: Measure the same volume of the sample as in step e in the electric heating evaporation box of the volatile substance enrichment device. After being processed by step c and step d, read the peak area at the Raman shift of the analyte, and compare it with the standard curve of the peak area - analyte content at the characteristic Raman shift to obtain the content of the analyte in the sample.

[0021] The present invention also provides a Raman spectroscopy monitoring device, which has a volatile substance enrichment device as described above.

[0022] The present invention also provides a medical monitoring device, which has a volatile substance enrichment device as described above.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] (1) The present invention vaporizes the sample and realizes the complete separation of the analyte from the matrix by utilizing the boiling point difference between the analyte and the matrix and the property that the analyte to be analyzed can penetrate through the waterproof semi-permeable membrane; (2) The metal nanoparticle composite film improves the sensitivity and accuracy of SERS detection; (3) The structure is simple, the volume is miniaturized, and it is convenient for disassembly, assembly and carrying; (4) The power supply device is easy to implement, and the detection and use of the device can be realized with a voltage lower than 12V; (5) The built-in electric heating evaporation box integrates the heat treatment process into the sample evaporation chamber, greatly shortening the detection time and improving the detection efficiency; (6) The sample sampling amount is small, 100 μL can meet the detection requirements, and the heat treatment efficiency is high; (7) The power supply is provided with a controllable transmission voltage switch, and the heating temperature range of the heating sheet can be adjusted according to the actual situation, with a wide application range; (8) It can be widely applied to the fields of environment, food and medical treatment, such as environmental sewage detection, food detection, human blood or urine detection, etc.; (9) It can be matched with the SERS rapid detection method. Description of the Drawings

[0025] Figure 1 is a schematic structural diagram of the present invention;

[0026] Figure 2 is a schematic structural diagram of the sample evaporation chamber in the present invention;

[0027] Figure 3 is the Raman spectrum and standard curve for analyzing the formaldehyde content in blood in the present invention;

[0028] Figure 4 is the Raman spectrum and standard curve for analyzing the methanol content in alcohol in the present invention;

[0029] Figure 5 is the Raman spectrum and standard curve for analyzing the benzenethiol content in industrial wastewater in the present invention;

[0030] In the figure: 1. Sample evaporation chamber, 1-1. Filling module I, 1-2. Filling module II, 1-3. Venturi structure, 1-4, 2. Piston cylinder, 3. Volatile enrichment tube, 4. Electric heating evaporation box, 5. Power supply, 6. Sealing cover, 7. Portable air pump, 8. Piston, 9. Waterproof semi-permeable membrane, 10. Metal nanoparticle composite film, 11. Absorbing liquid containing cavity, 12. Handheld Raman spectrometer, 13. Computer. Detailed Description of the Invention

[0031] The present invention will be further described in detail below with reference to the accompanying drawings.

[0032] As Figure 1A volatile substance enrichment device shown in the figure includes a sample evaporation chamber 1 in an inverted "T" shape, a piston cylinder 2, and a volatile substance enrichment tube 3. An electric heating evaporation box 4 for accommodating a sample to be measured is arranged in the horizontal tube of the sample evaporation chamber 1. The electric heating evaporation box 4 is connected to a power supply 5. One end of the vertical tube of the sample evaporation chamber 1 is provided with a sample inlet, and a sealing cover 6 is equipped on the sample inlet. An installation port for the electric heating evaporation box 4 is opened on the wall of the horizontal tube of the sample evaporation chamber 1. One end of the horizontal tube of the sample evaporation chamber 1 is an air inlet, and the other end is an air outlet. The air inlet is connected to a portable air pump 7 through a transmission tube, and the air outlet is communicated with the side wall of the piston cylinder 2 through a transmission tube; A piston 8 that can move up and down is arranged in the piston cylinder 2. The top of the piston cylinder 2 is communicated with the bottom of the volatile substance enrichment tube 3 through a transmission tube, and one-way valves are arranged on all the transmission tubes;

[0033] A filling module I 1-1 is arranged near the air inlet in the sample evaporation chamber 1, and a filling module II 1-2 is arranged near the air outlet. The electric heating evaporation box 4 is arranged between the filling module I 1-1 and the filling module II 1-2. The filling height of the filling module I 1-1, the height of the electric heating evaporation box 4, and the filling height of the filling module II 1-2 decrease in sequence. A Venturi structure 1-3 is formed among the filling module I 1-1, the electric heating evaporation box 4, and the filling module II 1-2. When the gas in the sample evaporation chamber 1 moves, a negative pressure area 1-4 is formed in the Venturi structure area;

[0034] A waterproof semi-permeable membrane 9 and a metal nanoparticle composite film 10 are sequentially arranged in the volatile substance enrichment tube 3 from bottom to top. An absorbent accommodation cavity 11 is formed between the waterproof semi-permeable membrane 9 and the metal nanoparticle composite film 10. The absorbent accommodation cavity 11 is filled with a volatile substance absorbent or a standard solution of a substance to be analyzed.

[0035] In order to make the detection result more accurate, the metal nanoparticle composite film 10 is an AgNPs@CA composite film. The preparation method of the AgNPs@CA composite film is: using silver nitrate as a raw material, hydrazine as a reducing agent, using an ethanol / water binary solution as a reaction medium, using cellulose acetate as a matrix, and prepared by an in-situ reduction method.

[0036] In order to enable the electric heating evaporation box 4 to heat up quickly, the electric heating evaporation box 4 includes a container for holding the sample to be measured and heating sheets arranged around the container. The heating sheets are provided with annularly arranged electric heating wires and coated with a silica gel layer.

[0037] In order to control the gas flow rate on the gas transmission pipe, a flow control valve 7 is arranged on all the gas transmission pipes.

[0038] In order to facilitate movement, the power supply 5 is a rechargeable power supply; in order to adjust the voltage of the power supply 5, the power supply 5 is provided with a controllable transmission voltage switch.

[0039] For safer use, the output voltage of the power supply 5 is below 12V.

[0040] For convenient carrying, the portable air pump 7 is a micro air pump, and the air inlet of the micro air pump is connected to the nitrogen cylinder.

[0041] Working principle: During operation, first assemble the present invention, put the sample to be tested into the electric heating evaporation box 4 from the sample inlet, and then seal it with the sealing cover 2. According to the sample situation, adjust the voltage of the power supply 5 to heat the sample, and then turn on the portable air pump 7 to provide a constant purge gas flow rate to the sample evaporation chamber 1, and purge the volatile substances to be trapped into the piston cylinder 2. When the piston 8 moves upward, the internal pressure in the piston cylinder 2 increases, so that the volatile gas purged from the sample evaporation chamber 1 quickly passes through the waterproof semi-permeable membrane 9, and then is absorbed and collected by the volatile matter absorption liquid, and the moisture in the volatile matter is blocked by the waterproof semi-permeable membrane 9; aim the handheld Raman spectrometer at the metal nanoparticle composite film 10 for detection; when the piston 8 moves downward, the internal pressure in the piston cylinder 2 decreases, and the gas in the sample evaporation chamber 1 enters the piston cylinder 2. The gas in the sample evaporation chamber 1 moves due to the replenishment of the gas source. When the gas in the sample evaporation chamber 1 moves, due to the characteristics of the Venturi structure 1-3, a negative pressure area 1-4 is generated above the sample to be tested, thereby accelerating the volatilization of the dissolved gas in the sample to be tested and increasing the test speed.

[0042] This embodiment also provides a Raman spectroscopy monitoring device, which has a volatile matter enrichment device as described above.

[0043] This embodiment also provides a medical monitoring device, which has a volatile matter enrichment device as described above.

[0044] The following specifically illustrates the usage method and application of the present invention for detecting volatile substances in different matrices through examples.

[0045] Example 1

[0046] To further illustrate the present invention, this example details the application of the volatile matter enrichment device in the detection of formaldehyde in blood. In this example, the substance to be analyzed and the target substance to be tested are formaldehyde. Using formaldehyde as the Raman signal molecule, the separation and enrichment effect of the volatile matter enrichment device is demonstrated. As Figure 1 shown, it specifically includes the following steps:

[0047] a. Sample pretreatment: Take a blood sample; prepare a series of formaldehyde standard solutions with different concentrations;

[0048] b. Preparation of the absorption liquid and derivatization reagent: Prepare the absorption liquid phenol reagent aqueous solution (1mg / mL) and the derivatization reagent NH4Fe(SO4)2 (dissolved and diluted with 0.1mol / L HCl to 10mg / mL);

[0049] c. Vaporization and enrichment treatment of samples and standard solutions: Pass the samples and standard solutions through the volatile matter enrichment device respectively to separate the analytes from the matrix. After being absorbed by the absorbent solution above the volatile matter enrichment tube 3, a derivatization reaction occurs. Measure 100 μL of blood samples and a series of formaldehyde standard solutions with concentration gradients and add them to the electric heating evaporation box 4. Stick the waterproof and breathable membrane 9 above the volatile matter enrichment tube 3, and inject the phenol reagent aqueous solution prepared in step b into the absorbent solution containing cavity 11. Turn on the power supply 5, seal it with the sealing cover 2, adjust the voltage of the power supply 5 to 6 V, and the heating sheet around the electric heating evaporation box 4 heats the solution inside. Turn on the portable air pump 7 to provide a constant purge gas flow rate to the sample evaporation chamber 1, and purge the volatile substances to be trapped into the piston cylinder 2. When the piston 8 moves upward, the internal pressure in the piston cylinder 2 increases, and the heated and vaporized formaldehyde is separated from the matrix and enters the volatile matter enrichment tube 3, where it is absorbed by the absorbent solution in the absorbent solution containing cavity 11. After the sample solution and standard solution are completely absorbed, stop heating. Add a small amount of 10 mg / mL NH4Fe(SO4)2 to the absorbent solution containing cavity 11, react for 7 min, and wait for measurement;

[0050] d. SERS detection: Place the flexible SERS substrate semi-transparent optical film above the metal nanoparticle composite film 10 and wait for 5 min. Point the handheld Raman spectrometer 12 at the optical film for detection, and the detection data will be displayed on the computer 13. Laser power: Medium high, integration time: 1 s;

[0051] e. Drawing of the standard curve: Measure 100 μL of a series of formaldehyde standard solutions with concentration gradients into the electric heating evaporation box 4 in the volatile matter enrichment device. After being processed by step c and step d, read the peak area at 1275 cm -1 Raman shift, and draw the peak area-formaldehyde content standard curve at 1275 cm -1 Raman shift;

[0052] f. Determination of sample concentration: Measure 100 μL of the sample solution into the electric heating evaporation box 4 in the volatile matter enrichment device. After being processed by step c and step d, read the peak area at 1275 cm -1 Raman shift, and compare it with the peak area-formaldehyde content standard curve at 1275 cm -1 Raman shift to obtain the formaldehyde content in the blood sample.

[0053] Please refer to Figure 3 , which is the Raman spectrum and standard curve for analyzing the formaldehyde content in blood by the volatile matter enrichment device. The linear range is 0.5 - 5 μg / ml, and the detection limit is 3×10 -4 μg / ml. The formaldehyde content in the blood sample can be calculated from the figure as 2.1 μg / ml.

[0054] Example 2

[0055] To further illustrate the present invention, this example details the application of a volatile enrichment device in the detection of methanol in alcohol. In this example, the substance to be analyzed and the target analyte are methanol. Using methanol as the Raman signal molecule, the separation and enrichment effect of the volatile enrichment device is demonstrated. As Figure 1 shown, it specifically includes the following steps:

[0056] a. Pretreatment of the sample: Take an alcohol sample; prepare a series of methanol standard solutions with different concentrations;

[0057] b. Preparation of the catalyst and absorbent solution: Weigh copper powder as the catalyst and prepare a 0.50 mg / mL acetylacetone aqueous solution (pH = 6.0, 0.50 g / mL ammonium acetate) as the absorbent solution;

[0058] c. Gasification and enrichment treatment of the sample and standard solution: Pass the sample and standard solution through the volatile enrichment device respectively, so that the analyte undergoes a catalytic reaction to form a SERS-active substance and then separates from the matrix, and is absorbed and enriched by the absorbent solution above the volatile enrichment tube 3. Add 0.05 g of copper powder to the electric heating evaporation box 4, measure 100 μL of the alcohol sample and a series of methanol standard solutions with concentration gradients and add them to the electric heating evaporation box 4 respectively. Stick a waterproof and breathable membrane 9 above the volatile enrichment tube 3, and inject the absorbent solution prepared in step b into the absorbent solution containing cavity 11. Turn on the power supply 5, seal it with the sealing cover 2, adjust the voltage of the power supply 5 to 6V, the heating sheet around the electric heating evaporation box 4 heats the solution inside it, turn on the portable air pump 7, provide a constant purge gas flow rate to the sample evaporation chamber 1, and purge the volatile substances to be trapped into the piston cylinder 2. When the piston 8 moves upward, the internal pressure in the piston cylinder 2 increases, and the heated methanol undergoes catalytic oxidation to generate formaldehyde and gasify, enters the volatile enrichment tube 3, and is absorbed by the absorbent solution in the absorbent solution containing cavity 11. After the sample solution and the standard solution are completely absorbed, stop heating and wait for 7 minutes to allow the reaction to proceed fully for measurement;

[0059] d. SERS detection: Place the flexible SERS substrate semi-transparent optical film above the metal nanoparticle composite film 10, wait for 5 minutes, aim the handheld Raman spectrometer 12 at the optical film for detection, and the detection data is displayed on the computer 13. Laser power: High, integration time: 3 s;

[0060] e. Plotting of the standard curve: Measure 100 μL of a series of methanol standard solutions with concentration gradients into the electric heating evaporation box 4 in the volatile enrichment device respectively. After being processed by steps c and d, read the peak area at a Raman shift of 1540 cm -1 and plot the peak area at 1540 cm -1Peak area at Raman shift - Methanol content standard curve;

[0061] f. Determination of sample concentration: Measure 100 μL of the sample solution into the electrically heated evaporation box 4 in the volatile matter enrichment device. After being treated by steps c and d, read the peak area at 1540 cm -1 Raman shift, and compare it with the peak area at 1540 cm -1 Raman shift - Methanol content standard curve to obtain the methanol content in the alcohol sample.

[0062] Please refer to Figure 4 , which is the Raman spectrum and standard curve for analyzing the methanol content in alcohol by the volatile matter enrichment device. The linear range is 4×10 -3 -2×10 -2 μg / ml, and the detection limit is 3×10 -3 μg / ml. The methanol content in the alcohol sample can be calculated from the figure as 8×10 -3 μg / ml.

[0063] Example 3

[0064] To further illustrate the present invention, this example details the detection application of thiophenol in industrial wastewater using the volatile matter enrichment device. In this example, the substance to be analyzed and the target analyte are thiophenol. Using thiophenol as the Raman signal molecule, as Figure 1 shown, it specifically includes the following steps:

[0065] a. Pretreatment of the sample: Take industrial sewage samples; Prepare a series of thiophenol standard solutions with different concentrations;

[0066] b. Preparation of the absorbent: Prepare 10% (v / v) ethanol aqueous solution as the absorbent;

[0067] c. Vaporization and enrichment treatment of samples and standard solutions: The samples and standard solutions are respectively passed through a volatile matter enrichment device to vaporize the analytes and separate them from the matrix, and they are absorbed and enriched by the absorbent solution above the volatile matter enrichment tube 3. Measure 100 μL of industrial sewage samples and a series of concentration gradients of benzenethiol standard solutions and add them to the electric heating evaporation box 4. Stick a waterproof and breathable membrane 9 above the volatile matter enrichment tube 3, and add the absorbent solution prepared in step b to the absorbent solution containing cavity 11. Turn on the power supply 5, seal it through the sealing cover 2, adjust the voltage of the power supply 5 to 6 V, and the heating sheet around the electric heating evaporation box 4 heats the solution inside it. Turn on the portable air pump 7 to provide a constant purge gas flow rate to the sample evaporation chamber 1, and purge the volatile substances to be trapped into the piston cylinder 2. When the piston 8 moves upward, the internal pressure in the piston cylinder 2 increases. The heated benzenethiol vaporizes and separates from the matrix, and enters the volatile matter enrichment tube 3, where it is absorbed by the absorbent solution in the absorbent solution containing cavity 11. After the sample solution and the standard solution are completely absorbed, stop heating and wait for 7 min to allow the reaction to proceed fully, and then wait for measurement;

[0068] d. SERS detection: Place the flexible SERS substrate semi-transparent optical film above the metal nanoparticle composite film 10 and wait for 5 min. Point the handheld Raman spectrometer 12 at the optical film for detection, and the detection data will be displayed on the computer 13. Laser power: High, integration time: 5 s;

[0069] e. Plotting of the standard curve: Measure 100 μL of a series of concentration gradients of benzenethiol standard solutions into the electric heating evaporation box 4 in the volatile matter enrichment device. After being processed by steps c and d, read the peak area at 1074 cm -1 Raman shift, and plot the peak area - benzenethiol content standard curve at 1074 cm -1 Raman shift;

[0070] f. Determination of the sample concentration: Measure 100 μL of the sample solution into the electric heating evaporation box 4 in the volatile matter enrichment device. After being processed by steps c and d, read the peak area at 1074 cm -1 Raman shift, and compare it with the peak area - benzenethiol content standard curve at 1074 cm -1 Raman shift to obtain the content of benzenethiol in the industrial sewage sample.

[0071] Please refer to Figure 5 for the Raman spectrum and standard curve of the volatile matter enrichment device for analyzing the content of benzenethiol in industrial sewage. The linear range is 0.2 - 1.0 mg / L, and the detection limit is 2×10 -3 mg / L. The content of benzenethiol in the industrial sewage sample can be calculated from the figure as 9.8 mg / L.

Claims

1. A volatile matter enrichment device, characterized in that: It includes a sample evaporation chamber (1) in an inverted "T" shape, a piston cylinder (2) and a volatile enrichment tube (3). An electrically heated evaporation box (4) for accommodating the sample to be tested is arranged in the horizontal tube of the sample evaporation chamber (1). The electrically heated evaporation box (4) is connected to a power supply (5). One end of the vertical tube of the sample evaporation chamber (1) is provided with a sample inlet, and a sealing cover (6) is provided for the sample inlet. An insertion port for the electrically heated evaporation box (4) is opened on the wall of the horizontal tube of the sample evaporation chamber (1). One end of the horizontal tube of the sample evaporation chamber (1) is an air inlet, and the other end is an air outlet. The air inlet is connected to a portable air pump (7) through a transmission tube, and the air outlet is communicated with the side wall of the piston cylinder (2) through a transmission tube; A filling module I (1-1) is arranged near the air inlet at the inner bottom of the horizontal tube of the sample evaporation chamber (1), and a filling module II (1-2) is arranged near the air outlet. The electrically heated evaporation box (4) is arranged between the filling module I (1-1) and the filling module II (1-2). The filling height of the filling module I (1-1), the filling height of the filling module II (1-2), and the height of the electrically heated evaporation box (4) decrease in sequence. A Venturi structure (1-3) is formed among the filling module I (1-1), the electrically heated evaporation box (4), and the filling module II (1-2). When the gas moves in the sample evaporation chamber (1), a negative pressure area (1-4) is formed in the Venturi structure area; A waterproof semi-permeable membrane (9) and a metal nanoparticle composite film (10) are sequentially arranged in the volatile enrichment tube (3) from bottom to top. An absorbent accommodation cavity (11) is formed between the waterproof semi-permeable membrane (9) and the metal nanoparticle composite film (10). The absorbent accommodation cavity (11) is filled with a volatile absorbent or a standard solution of the substance to be analyzed.

2. The volatile matter enrichment device according to claim 1, wherein: The metal nanoparticle composite film (10) is an AgNPs@CA composite film. The preparation method of the AgNPs@CA composite film is as follows: using silver nitrate as a raw material, hydrazine as a reducing agent, using an ethanol / water binary solution as a reaction medium, and using cellulose acetate as a matrix, and prepared by an in-situ reduction method.

3. The volatile matter enrichment device according to claim 1 or 2, characterized in that: The absorbent contains a derivatization reagent for the substance to be analyzed.

4. The volatile matter enrichment device according to claim 1 or 2, characterized in that: The electrically heated evaporation box (4) includes a container for holding the sample to be tested and heating sheets arranged around the container. The heating sheets are provided with annularly arranged electric heating wires and coated with a silica gel layer.

5. The volatile enrichment device according to claim 1 or 2, characterized in that: Flow control valves are provided on all the transmission tubes.

6. The volatile enrichment device according to claim 1 or 2, characterized in that: The power supply (5) is a rechargeable power supply and is provided with a controllable transmission voltage switch. The output voltage of the power supply (5) is below 12V.

7. The volatile enrichment device according to claim 1 or 2, characterized in that: The portable air pump (7) is a micro air pump, and the air inlet of the micro air pump is connected to a nitrogen cylinder.

8. The application of a volatile enrichment device according to claim 1, characterized in that, It includes the following steps: a. Pretreatment of the sample: Take the sample to be tested and prepare a series of standard solutions of the analyte with different concentrations; b. Preparation of the absorption solution or the absorption solution and the derivatization reagent: When the analyte does not have a surface-enhanced Raman spectral response, a derivatization reagent needs to be added to the absorption solution to cause the analyte to undergo a derivatization reaction and be converted into a substance with a strong surface-enhanced Raman response; c. Vaporization and enrichment treatment of the sample and the standard solution: Turn on the power supply (5), seal it through the sealing cover (6), adjust the voltage of the power supply (5), and the heating sheet around the electric heating evaporation box (4) heats the sample in the box. Turn on the portable air pump (7) to provide a constant purge gas flow rate into the sample evaporation chamber (1), and purge the volatile substances to be trapped into the piston cylinder (2). When the piston (8) moves upward, the internal pressure in the piston cylinder (2) increases, and the sample and the standard solution pass through the sample evaporation chamber (1) to separate the analyte from the matrix. The volatilized gas passes through the waterproof semi-permeable membrane (9) and is absorbed and enriched by the absorption solution in the absorption solution chamber (11). After the analyte in the sample and the standard solution is completely absorbed, stop heating; d. SERS detection: Place the flexible SERS substrate semi-transparent optical film above the metal nanoparticle composite film (10), wait for 5 minutes, and use the handheld Raman spectrometer to detect the optical film; e. Plotting of the standard curve: Take a series of standard solutions with different concentrations in the electric heating evaporation box (4) of the volatile substance enrichment device. After being processed by steps c and d, read the peak area at the characteristic Raman shift of the analyte, and plot the standard curve of the peak area at the characteristic Raman shift - analyte content; f. Determination of the sample concentration: Measure the same volume of the sample as in step e in the electric heating evaporation box (4) of the volatile substance enrichment device. After being processed by steps c and d, read the peak area at the Raman shift of the analyte, Compare with the standard curve of the peak area at the characteristic Raman shift - analyte content to obtain the content of the analyte in the sample.

9. A Raman spectroscopy monitoring device, characterized in that: This device has a volatile substance enrichment device as described in claim 1.

10. A medical monitoring device, characterized in that: This device has a volatile substance enrichment device as described in claim 1.

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