Terahertz online detection method and device for residual quantity of sulfur dioxide after traditional Chinese medicine sulphitation

Abstract

The invention relates to a terahertz online detection method and device for sulfur dioxide residual quantity after traditional Chinese medicine sulphitation. The detection method comprises the following steps: S1, sulphitation is performed on a traditional Chinese medicine sample by using sulfur dioxide; s2, sampling the traditional Chinese medicine sample subjected to sulfur fumigation, and carrying out terahertz detection on the obtained sample to obtain a detection result of the residual quantity of sulfur dioxide; s3, performing sulfur dioxide residual quantity detection on the sample subjected to terahertz detection by using an acid-base titration method, and comparing a detection result with a detection result in S2; and S4, performing neural network training by using the detection result data in the S2 and the detection result data in the S3 to obtain a network model, and predicting the residual amount of sulfur dioxide after the traditional Chinese medicine sulphitation by using the network model. According to the method, in a working environment of simulating sulfur combustion, a terahertz technology is used for detecting the residual quantity of sulfur dioxide in the sulfur fumigation traditional Chinese medicine, and then data training is carried out through an acid-base titration method in combination with a neural network.

Description

Technical Field

[0001] The invention belongs to the technical field of sulfur dioxide residual detection of sulfur-fumigated traditional Chinese medicines, and in particular relates to a terahertz online detection method and device for sulfur dioxide residual after sulfur-fumigation of traditional Chinese medicines. Background Art

[0002] The most common and most prominent problem in Chinese herbal medicines is the addition of sulfur to preserve them for a long time. According to relevant regulations, the residual sulfur dioxide in medicinal materials and decoction pieces (except minerals) shall not exceed 150 mg / kg. However, there are still many unscrupulous drug dealers who over-fumigate Chinese medicines with sulfur in order to preserve them dry, resulting in sulfur dioxide residues in Chinese medicines exceeding national regulations. Sulfur-fumigated Chinese medicines may also cause damage to liver and kidney function, because the heavy metals contained in them, such as lead and mercury, will accumulate in the human body, and long-term intake may cause chronic poisoning. In addition, the oxidizing property of sulfur will also destroy the active ingredients in Chinese herbal medicines, thereby reducing the therapeutic effect of the medicine. At present, there are acid-base titration and gas chromatography methods for detecting the residual sulfur dioxide in sulfur-fumigated Chinese medicines. The acid-base titration method is low in cost but may produce false positives, while the gas chromatography method is accurate but expensive.

[0003] Therefore, it is necessary to design a terahertz online detection method and device for the residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a terahertz online detection method and device for residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine, and to detect the residual sulfur dioxide of sulfur fumigated traditional Chinese medicine by terahertz technology in a working environment simulating sulfur combustion, and then to perform data training by acid-base titration and combining neural network, so as to better detect the residual sulfur dioxide in sulfur fumigated traditional Chinese medicine and further improve the standardization and reliability of sulfur fumigation of traditional Chinese medicine.

[0005] To achieve the above object, the present invention provides the following scheme: a terahertz online detection method for residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine, comprising the following steps:

[0006] S1. Use sulfur dioxide to fumigate the traditional Chinese medicine samples;

[0007] S2. Sampling the traditional Chinese medicine samples after sulfur fumigation, performing terahertz detection on the obtained samples, and obtaining the detection results of sulfur dioxide residue;

[0008] S3, using acid-base titration method to detect the residual sulfur dioxide content of the sample after terahertz detection, and comparing the detection result with the detection result of S2;

[0009] S4. Use the test result data of S2 and the test result data of S3 to perform neural network training to obtain a network model, and use the network model to predict the sulfur dioxide residue after sulfur fumigation of traditional Chinese medicine.

[0010] Preferably, in S1, sulfur dioxide is produced by igniting sulfur, and the sulfur fumigation time is 12 hours.

[0011] Preferably, in S2, the Chinese medicine sample is divided into several portions of the same mass, and the several portions of the Chinese medicine samples of the same mass are placed in order from bottom to top at equal intervals, sulfur is placed under the Chinese medicine sample at the bottom, ignited to produce sulfur dioxide, and the several portions of the Chinese medicine samples are fumigated with sulfur. The sulfur-fumigated Chinese medicine samples are subjected to terahertz detection to obtain terahertz reflectivity information and absorptivity information, the terahertz reflectivity information and absorptivity information are analyzed, and the sulfur dioxide residues at different distances between the Chinese medicine samples and sulfur are evaluated to obtain the detection results.

[0012] Preferably, in S3, the process of acid-base titration is to grind the sulfur-fumigated Chinese medicine sample into powder, and reset it in a two-necked round-bottom flask, then add water and hydrochloric acid solution to the two-necked round-bottom flask, connect a graduated separatory funnel, and introduce nitrogen to the bottom of the two-necked round-bottom flask, connect a reflux condenser, connect an air guide tube to the upper end of the condenser, insert the air guide tube into the bottom of the conical flask, add water and starch indicator solution as absorption liquid into the conical flask, place it on a magnetic stirrer and stir it continuously, heat the solution in the two-necked round-bottom flask to boiling and keep it slightly boiling, then titrate with iodine titrant, and correct the titration result with a blank test.

[0013] Preferably, the calculation formula for the residual sulfur dioxide is:

[0014]

[0015] Where:

[0016] A is the volume of iodine titrant consumed by the traditional Chinese medicine sample after sulfur fumigation;

[0017] B is the volume of iodine titrant consumed in the blank experiment;

[0018] C is the concentration of iodine titrant;

[0019] W is the weight of the Chinese medicine sample after sulfur fumigation;

[0020] 0.032 means the concentration is 1 mol·L per 1 mL -1 of iodine titrant equivalent to the weight of sulfur dioxide.

[0021] Preferably, the training method of the neural network is: taking the terahertz detection spectrum data as input, and the sulfur dioxide residue detected by the acid-base titration method as output, combining the input and the output into a data set, substituting them into a convolutional neural network for training, and constructing a prediction model;

[0022] The convolutional layer filter of the convolutional neural network is 3×3, the maximum pooling layer window is 2×2, and the initial step size is set to 1.

[0023] A terahertz online detection method device for residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine, comprising:

[0024] Box;

[0025] A position adjustment mechanism, wherein the position adjustment mechanism is arranged outside the box, and a terahertz transmitter is arranged on the position adjustment mechanism;

[0026] A sulfur dioxide generating mechanism, wherein the sulfur dioxide generating mechanism is arranged at the bottom of the box;

[0027] A plurality of traditional Chinese medicine sulfur fumigation mechanisms, wherein the plurality of traditional Chinese medicine sulfur fumigation mechanisms are arranged above the sulfur dioxide generating mechanism at equal intervals from bottom to top;

[0028] The air blowing mechanism is arranged on one side of the sulfur dioxide generating mechanism.

[0029] Preferably, a terahertz probe is provided at the bottom end of the integrated terahertz transmitter.

[0030] Preferably, the position adjustment mechanism includes two slides, which are respectively fixedly connected to the bottom and top of the outer wall of the box body, a movable slide rod is slidably arranged between the two slides, a plurality of limiting holes are provided on the movable slide rod, and the plurality of limiting holes are arranged at equal intervals, a display window positioning plate is slidably connected to the movable slide rod, the display window positioning plate and the movable slide rod are perpendicular to each other, a first slide groove is provided on the display window positioning plate, and the terahertz transmitter is slidably arranged in the first slide groove.

[0031] Preferably, the sulfur dioxide generating mechanism comprises a fume hood window, the top of which is open, the fume hood window is movably arranged at the bottom of the box body, a combustion dish is arranged inside the fume hood window, a ventilation window is opened on the side wall of the fume hood window close to the air blowing mechanism, and a window and a handle are arranged on the side wall of the fume hood window away from the air blowing mechanism;

[0032] The Chinese medicine sulfur fumigation mechanism comprises a closed display window, a plurality of the closed display windows are arranged above the ventilation display window at equal intervals from bottom to top, and the top wall and the bottom wall of the closed display window are both provided with ventilation holes;

[0033] The air blowing mechanism comprises a fan, and the fan is arranged at the bottom of the box body, and the fan corresponds to the ventilation window.

[0034] Compared with the prior art, the present invention has the following advantages and technical effects:

[0035] The present invention combines the detection of sulfur dioxide residue by traditional acid-base titration method with terahertz nondestructive testing technology, obtains the connection and trend prediction of terahertz intensity data and sulfur dioxide residue through neural network, and improves the accuracy and reliability of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor:

[0037] Figure 1 is a flow chart of the detection method of the present invention;

[0038] Figure 2 It is a schematic diagram of the overall structure of the device of the present invention;

[0039] Figure 3 It is a rear view of the device of the present invention;

[0040] Figure 4 It is a schematic diagram of the structure of the fume hood window of the present invention.

[0041] Among them, 1. ventilation window; 2. closed window; 3. terahertz transmitter; 4. terahertz probe; 5. window positioning plate; 6. first slide slot; 7. control panel; 8. steering arm; 9. limit hole; 10. moving slide rod; 11. knob; 12. universal wheel; 13. box; 14. second slide slot; 15. window; 16. handle; 17. combustion dish; 18. ventilation window; 19. fan. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Reference Figures 1 to 4 As shown, the present invention provides a terahertz online detection method for the residual amount of sulfur dioxide after traditional Chinese medicine fumigation, comprising the following steps:

[0045] S1. Use sulfur dioxide to fumigate the traditional Chinese medicine samples;

[0046] S2. Sampling the traditional Chinese medicine samples after sulfur fumigation, performing terahertz detection on the obtained samples, and obtaining the detection results of sulfur dioxide residue;

[0047] S3, using acid-base titration method to detect the residual sulfur dioxide content of the sample after terahertz detection, and comparing the detection result with the detection result of S2;

[0048] S4. Use the test result data of S2 and the test result data of S3 to perform neural network training to obtain a network model, and use the network model to predict the sulfur dioxide residue after sulfur fumigation of traditional Chinese medicine.

[0049] The scheme is further optimized. In S1, sulfur dioxide is produced by burning sulfur, and the fumigation time is 12 hours.

[0050] The box 13 is moved to a suitable position by the universal wheel 12. Sulfur is placed in the combustion dish 17 of the bottom ventilation cabinet window 1 and ignited, and the Chinese medicine samples are placed in the four closed cabinet windows 2 on the upper layer and fumigated with sulfur for 12 hours.

[0051] To further optimize the scheme, in S2, the Chinese medicine sample is divided into several portions of the same mass, and the several portions of the Chinese medicine samples of the same mass are placed in order from bottom to top at equal intervals, sulfur is placed under the Chinese medicine sample at the bottom and ignited to produce sulfur dioxide, and the several portions of the Chinese medicine samples are fumigated with sulfur, and the fumigated Chinese medicine samples are subjected to terahertz detection to obtain terahertz reflectivity information and absorptivity information, and the terahertz reflectivity information and absorptivity information are analyzed by the sulfur-fumigation Chinese medicine evaluation system to evaluate the sulfur dioxide residues at different distances between the Chinese medicine samples and sulfur to obtain the test results.

[0052] Further optimization scheme, in S3, the process of acid-base titration is to grind the sulfur-fumigated Chinese medicine sample into powder, weigh 10g and put it in a two-necked round-bottom flask, then add 450mL of water and 6mol·L -1 10mL of hydrochloric acid solution was added to the flask, and a graduated separatory funnel was connected. Nitrogen was introduced into the bottom of the two-necked round-bottom flask. A reflux condenser was connected. A gas guide tube was connected to the upper end of the condenser. The gas guide tube was inserted into the bottom of a 250mL conical flask. 125mL of water and 1mL of starch indicator solution were added to the conical flask as the absorption liquid. The flask was placed on a magnetic stirrer and stirred continuously. The solution in the two-necked round-bottom flask was heated to boiling and kept at a slight boiling for 5 minutes. Then, a 0.0109mol·L-1 Titrate with iodine titrant until the blue or purple color persists for 20 seconds and correct the titration result with a blank test.

[0053] To further optimize the scheme, the calculation formula for the residual sulfur dioxide is:

[0054]

[0055] Where:

[0056] A is the volume of iodine titrant consumed by the traditional Chinese medicine sample after sulfur fumigation;

[0057] B is the volume of iodine titrant consumed in the blank experiment;

[0058] C is the concentration of iodine titrant;

[0059] W is the weight of the Chinese medicine sample after sulfur fumigation;

[0060] 0.032 means the concentration is 1 mol·L per 1 mL -1 of iodine titrant equivalent to the weight of sulfur dioxide.

[0061] To further optimize the scheme, the training method of the neural network is as follows: taking the terahertz detection spectrum data as input and the sulfur dioxide residue detected by the acid-base titration method as output, combining the input and output into a data set, substituting it into a convolutional neural network for training, and constructing a prediction model;

[0062] The convolutional layer filter of the convolutional neural network is 3×3, the maximum pooling layer window is 2×2, and the initial step size is set to 1.

[0063] A terahertz online detection method device for residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine, comprising:

[0064] Box 13;

[0065] A position adjustment mechanism, which is arranged outside the box 13 and has a terahertz transmitter 3 arranged on it;

[0066] Sulfur dioxide generating mechanism, the sulfur dioxide generating mechanism is arranged at the bottom of the box 13;

[0067] A number of traditional Chinese medicine sulfur fumigation mechanisms, which are evenly spaced from bottom to top above the sulfur dioxide generating mechanism;

[0068] The air blowing mechanism is arranged on one side of the sulfur dioxide generating mechanism.

[0069] To further optimize the solution, a terahertz probe 4 is provided at the bottom of the terahertz transmitter 3 .

[0070] The terahertz probe 4 is installed at the lower end of the terahertz transmitter 3 to transmit and receive terahertz signals and obtain terahertz reflectivity and absorptivity information.

[0071] The outer wall of the box body 13 is fixedly connected with a control panel 7 via a steering arm 8 . The control panel 7 is used to control the movement and monitoring of the terahertz transmitter 3 .

[0072] Furthermore, a knob 11 is provided at the top of the terahertz transmitter 3 , and the knob 11 cooperates with the first slide slot 6 to drive the terahertz transmitter 3 to move in the X-axis direction so as to adjust the position of the terahertz transmitter 3 on the test sample.

[0073] A further optimized solution is that the position adjustment mechanism includes two slides, which are respectively fixedly connected to the bottom and top of the outer wall of the box body 13, and a movable slide bar 10 is slidably arranged between the two slides. The movable slide bar 10 is provided with a plurality of limit holes 9, and the plurality of limit holes 9 are arranged at equal intervals. A display window positioning plate 5 is slidably connected to the movable slide bar 10, and the display window positioning plate 5 and the movable slide bar 10 are perpendicular to each other. A first slide groove 6 is provided on the display window positioning plate 5, and the terahertz transmitter 3 is slidably arranged in the first slide groove 6.

[0074] Furthermore, the movable slide rod 10 is slidably disposed in a second slide groove 14 provided on the slide seat.

[0075] The limiting hole 9 is used to fix the detection position of the integrated terahertz transmitter 3 so that the integrated terahertz transmitter 3 can move in the Y-axis direction on the movable slide bar 10 .

[0076] Further optimizing the scheme, the sulfur dioxide generating mechanism comprises a fume hood window 1, the top of the fume hood window 1 is open, the fume hood window 1 is movably arranged at the bottom of the box body 13, a combustion dish 17 is arranged inside the fume hood window 1, a ventilation window 18 is opened on the side wall of the fume hood window 1 close to the blowing mechanism, and a window 15 and a handle 16 are arranged on the side wall of the fume hood window 1 away from the blowing mechanism;

[0077] The Chinese medicine sulfur fumigation mechanism comprises a closed display window 2, wherein a plurality of closed display windows 2 are evenly spaced from bottom to top above the ventilation display window 1, and the top wall and the bottom wall of the closed display window 2 are both provided with ventilation holes;

[0078] The air blowing mechanism includes a fan 19 , which is disposed at the bottom of the box body 13 and corresponds to the ventilation window 18 .

[0079] The ventilation cabinet window 1 is cooled by the fan 19 .

[0080] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0081] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope of the present invention.

Claims

1. A terahertz online detection method for residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine, characterized in that: The following steps are involved: S1. Use sulfur dioxide to fumigate the traditional Chinese medicine samples; S2. Sampling the traditional Chinese medicine samples after sulfur fumigation, performing terahertz detection on the obtained samples, and obtaining the detection results of sulfur dioxide residue; S3, using acid-base titration method to detect the residual sulfur dioxide content of the sample after terahertz detection, and comparing the detection result with the detection result of S2; S4. Use the test result data of S2 and the test result data of S3 to perform neural network training to obtain a network model, and use the network model to predict the sulfur dioxide residue after sulfur fumigation of traditional Chinese medicine.

2. The terahertz online detection method for residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine according to claim 1, characterized in that: In S1, sulfur dioxide is produced by burning sulfur, and the fumigation time is 12 hours.

3. The terahertz online detection method for residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine according to claim 2, characterized in that: In S2, the Chinese medicine sample is divided into several portions of the same mass, and the several portions of the Chinese medicine samples of the same mass are placed in order from bottom to top at equal intervals, sulfur is placed under the Chinese medicine sample at the bottom and ignited to produce sulfur dioxide, and the several portions of the Chinese medicine samples are fumigated with sulfur. The sulfur-fumigated Chinese medicine samples are subjected to terahertz detection to obtain terahertz reflectivity information and absorptivity information, and the terahertz reflectivity information and absorptivity information are analyzed to evaluate the sulfur dioxide residues at different distances between the Chinese medicine samples and sulfur to obtain the detection results.

4. The terahertz online detection method for sulfur dioxide residue after sulfur fumigation of traditional Chinese medicine according to claim 1, characterized in that: In S3, the process of acid-base titration is to grind the sulfur-fumigated Chinese medicine sample into powder, and reset it in a two-necked round-bottom flask, then add water and hydrochloric acid solution to the two-necked round-bottom flask, connect a graduated separatory funnel, and introduce nitrogen into the bottom of the two-necked round-bottom flask, connect a reflux condenser, connect an air guide tube to the upper end of the condenser, insert the air guide tube into the bottom of the conical flask, add water and starch indicator solution as absorption liquid into the conical flask, place it on a magnetic stirrer and stir it continuously, heat the solution in the two-necked round-bottom flask to boiling and keep it slightly boiling, then titrate it with iodine titrant, and correct the titration result with a blank test.

5. The terahertz online detection method for residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine according to claim 4, characterized in that: The calculation formula for residual sulfur dioxide is: Where: A is the volume of iodine titrant consumed by the traditional Chinese medicine sample after sulfur fumigation; B is the volume of iodine titrant consumed in the blank experiment; C is the concentration of iodine titrant; W is the weight of the Chinese medicine sample after sulfur fumigation; 0.032 means the concentration is 1 mol·L per 1 mL -1 of iodine titrant equivalent to the weight of sulfur dioxide.

6. The terahertz online detection method for residual sulfur dioxide after sulfur fumigation of traditional Chinese medicine according to claim 5, characterized in that: The training method of the neural network is: taking the terahertz detection spectrum data as input, and the sulfur dioxide residue detected by the acid-base titration method as output, combining the input and the output into a data set, substituting it into a convolutional neural network for training, and constructing a prediction model; The convolutional layer filter of the convolutional neural network is 3×3, the maximum pooling layer window is 2×2, and the initial step size is set to 1.

7. A device for a terahertz online detection method of sulfur dioxide residues after sulfur fumigation of traditional Chinese medicine according to any one of claims 1 to 6, characterized in that: include Box body (13); A position adjustment mechanism, the position adjustment mechanism being arranged outside the box (13), and the position adjustment mechanism being provided with a terahertz emission integrated device (3); A sulfur dioxide generating mechanism, the sulfur dioxide generating mechanism being arranged at the bottom of the box (13); A plurality of traditional Chinese medicine sulfur fumigation mechanisms, wherein the plurality of traditional Chinese medicine sulfur fumigation mechanisms are arranged above the sulfur dioxide generating mechanism at equal intervals from bottom to top; The air blowing mechanism is arranged on one side of the sulfur dioxide generating mechanism.

8. The device of the terahertz online detection method of the sulfur dioxide residual amount after the traditional Chinese medicine sulfur fumigation according to claim 7 is characterized in that, A terahertz probe (4) is arranged at the bottom end of the terahertz emission integrated device (3).

9. The device of the terahertz online detection method of the sulfur dioxide residual amount after the traditional Chinese medicine sulfur fumigation according to claim 7 is characterized in that, The position adjustment mechanism comprises two slide seats, the two slide seats are respectively fixedly connected to the bottom end and the top end of the outer wall of the box body (13), a movable slide bar (10) is slidably arranged between the two slide seats, a plurality of limiting holes (9) are provided on the movable slide bar (10), and the plurality of limiting holes (9) are arranged at equal intervals, a window positioning plate (5) is slidably connected to the movable slide bar (10), the window positioning plate (5) and the movable slide bar (10) are perpendicular to each other, a first sliding groove (6) is provided on the window positioning plate (5), and the terahertz transmitter (3) is slidably arranged in the first sliding groove (6).

10. The device of the terahertz online detection method of the sulfur dioxide residual amount after the traditional Chinese medicine sulfur fumigation according to claim 7 is characterized in that, The sulfur dioxide generating mechanism comprises a fume hood window (1), the top of the fume hood window (1) is open, the fume hood window (1) is movably arranged at the bottom of the box body (13), a combustion dish (17) is arranged inside the fume hood window (1), a ventilation window (18) is opened on the side wall of the fume hood window (1) close to the blowing mechanism, and a window (15) and a handle (16) are arranged on the side wall of the fume hood window (1) away from the blowing mechanism; The Chinese medicine sulfur fumigation mechanism comprises a closed display window (2), wherein a plurality of the closed display windows (2) are arranged above the ventilation display window (1) at equal intervals from bottom to top, and the top wall and the bottom wall of the closed display window (2) are both provided with ventilation holes; The air blowing mechanism comprises a fan (19), the fan (19) is arranged at the bottom of the box body (13), and the fan (19) corresponds to the ventilation window (18).

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