Reaction device and detection method for photometric colorimetry detection

Abstract

The present invention provides a reaction device and a detection method for photometric colorimetry detection. The reaction device comprises a reaction main body unit, a detection unit, a liquid inlet unit and a stirring unit. The detection unit comprises a light source emitting part and a light source signal collecting part. The bottom side wall of the reaction cup holder is provided with two openings arranged on opposite sides, and the two openings are respectively embedded with the light source emitting part and the light source signal collecting part. The light source emitted by the light source emitting part irradiates the solution in the reaction cup and sends a light intensity signal to the light source signal collecting part. The present invention uses photometric colorimetry to accurately determine the end point of titration analysis, that is, the chemical variable point, so as to accurately and automatically analyze the concentration of the potion.

Description

Technical Field

[0001] The invention belongs to reaction equipment for detecting reagent concentration, and in particular relates to a reaction device and a detection method for photometric colorimetry detection. Background Art

[0002] As the standards for industrialization become increasingly stringent, the requirements for solution concentration detection accuracy are becoming increasingly stringent. The traditional detection method records data after adding the reaction reagent. The detection accuracy of this method is not high, and the reaction device has a complex structure and is difficult to assemble. The detection accuracy of the photometric colorimetry is not high, and there is also the problem of cross-contamination between reagents. The patent number CN201920567541.0 submitted by the applicant earlier is called an automated online detection device. According to this situation, we designed a reaction device used in an automated online detection device. The color intensity of the colored solution generated after the color of the substance being tested or the addition of the developer is proportional to the substance content. The substance in the solution produces an absorption effect on light under the irradiation and excitation of light. Therefore, according to the intensity of light absorbed by the colored solution, the degree of light intensity reduction has a certain proportional relationship with the concentration of the substance, which conforms to the principle of colorimetry, the Lambert-Beer law, and determines the appropriate wavelength for testing the sample solution. The photometric colorimetry method is used to accurately determine the end point of the titration analysis, that is, the chemical variable point, so as to accurately and automatically analyze the concentration of the potion. Summary of the invention

[0003] In order to solve the above technical problems, the technical problem to be solved by the present invention is to provide a reaction device and a detection method for photometric colorimetry detection, which have a simple structure, are easy to install, reliable in operation, and simple in maintenance. In particular, the end point of the titration analysis, that is, the chemical variable point, is accurately determined by photometric colorimetry, so as to accurately and automatically analyze the concentration of the substance to be tested. The independent design of multiple liquid inlet hard tubes for different reagents avoids the problem of cross contamination between reagents.

[0004] The technical scheme of the frame structure of the present invention is as follows: a reaction device for photometric colorimetry detection, comprising a reaction device installed on a vertical panel, the reaction device comprising a reaction main unit, a detection unit, a liquid inlet unit and a stirring unit, the reaction main unit comprising a reaction cup seat, and a reaction cup made of transparent quartz glass is placed in the reaction cup seat cavity, and a cup seat cover is installed above the reaction cup seat; the stirring unit comprises a stirrer bracket arranged at the bottom of the reaction cup seat, a groove portion is arranged on the stirrer bracket, a magnetic stirrer is placed in the groove portion, and the magnetic stirrer cooperates with a magnetic stirring rotor placed inside the reaction cup; the detection unit comprises a light source emitting part and a light source signal collecting part, two openings arranged on opposite sides are arranged on the bottom side wall of the reaction cup seat, and the two openings are respectively embedded with the light source emitting part and the light source signal collecting part; the light source emitted by the light source emitting part irradiates the solution in the reaction cup and sends a light intensity signal to the light source signal collecting part; the liquid inlet unit comprises a plurality of liquid inlet hard pipes, each of which is respectively connected to the liquid inlet through hole also arranged on the cup seat cover.

[0005] As a preferred structure, the reaction cup adopts a cylindrical structure, an overflow port is provided on the upper curved wall of the reaction cup, and a drainage port is provided on the bottom curved wall of the reaction cup.

[0006] As a preferred structure, the drain port and the overflow port are located on the same plane.

[0007] As a preferred structure, the reaction cup seat and the cup seat cover are both made of opaque plastic material.

[0008] As a preferred structure, an observation window is left on the front end surface of the reaction cup holder, and a detachable and light-proof window cover is installed at the observation window.

[0009] As a preferred structure, the rear end surface of the reaction cup holder is provided with two through holes, and the two through holes are used for the passage of the discharge port and the overflow port respectively.

[0010] As a preferred structure, a fixing bracket is further installed on the rear end surface of the reaction cup holder, and the fixing bracket fixes the reaction cup holder on the vertical panel.

[0011] As a preferred structure, the liquid inlet hard tube is made of PTFE material, and its diameter is 3 mm. The liquid inlet hard tube is provided with an inverted cone type ferrule joint on the outside, and the ferrule joint is fixed to the liquid inlet through hole.

[0012] The present invention also provides a detection method of a reaction device for photometric colorimetry detection, and the detection method of the reaction device comprises the following steps:

[0013] S1: Determine the substance to be tested in the sample solution, determine the color developer that chemically reacts with the substance to be tested to produce a solution color change, determine the monochromatic light according to the relationship between the color of the solution and the color of the absorbed light, and select the monochromatic light of appropriate wavelength;

[0014] S2: The sample liquid and pure water are respectively discharged into the reaction cup through a plurality of liquid inlet hard tubes, and the reaction cup is rinsed, and then discharged from the discharge port at the bottom curved wall of the reaction cup;

[0015] S3: Drain the sample liquid into the reaction cup through the liquid inlet hard tube to ensure that the liquid level of the sample liquid is at

[0016] Above the light source signal detection line, the light source signal is sent from the light source transmitting unit to the light source signal collecting unit;

[0017] S4: Titrate the developer through another liquid inlet hard tube, and use the mathematical expression A=Kcb of Lambert-Beer's law to calculate, where A is the absorbance, that is, the degree of absorption of monochromatic light when it passes through the solution, calculated according to the incident light intensity of the light source emitting part and the incident light intensity received by the light source signal collecting part, K ​​is the absorption coefficient, which is a constant for the same substance and incident light of a certain wavelength, b is the optical path, that is, the distance from one end of the light source to the other end of the reaction cup, and the concentration of the substance to be tested C is calculated;

[0018] S5: During the titration process, the developer generates several sets of data based on the number of titration steps and the calculated concentration and fills them into the XY axis, where the X axis is the number of titration steps and the Y axis is the concentration of the substance to be measured. The data are connected in sequence to find the titration end point, which is the maximum value of the concentration of the substance to be measured. The titration end point is determined to be the mutation point based on the slope value;

[0019] S6: Record the number of titration steps of the developer at the titration endpoint, and calculate using the formula ST1= K1*R1, where R1 is the number of titration steps at the titration endpoint and K1 is the known slope value in the XY axis, thereby obtaining the concentration value of the substance to be tested in ST1 and completing the entire detection process.

[0020] The beneficial effects of the present invention are: the overall structural design of the reaction device of the present invention is reasonable, the operation is stable and reliable, the liquid inlet unit is controlled to complete the sampling work of the reaction main unit, the solution in the reaction main unit is stirred under the stirring unit to improve the reaction efficiency, and the solution is detected and analyzed in the light source emitting part and the light source signal collecting part of the detection unit.

[0021] The detection method of the present invention can accurately determine the endpoint of the titration analysis, that is, the chemical variable point, and can accurately and reliably measure the concentration of the substance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic cross-sectional structural diagram of the reaction device of the present invention.

[0023] Figure 2 It is a schematic diagram of the three-dimensional structure of the reaction cup of the present invention.

[0024] Figure 3 It is a schematic diagram of the three-dimensional structure of the reaction cup holder of the present invention.

[0025] Figure 4 It is a schematic diagram of the three-dimensional structure of the fixing bracket of the present invention.

[0026] Figure 5 This is a table showing the relationship between the color of the solution and the color of the absorbed light.

[0027] Figure numerals: 1. reaction cup; 2. reaction cup holder; 3. light source emitting part; 4. light source signal collecting part; 5. cup holder cover; 6. ferrule connector; 7. liquid inlet tube; 8. magnetic stirrer; 9. stirrer bracket; 10. overflow port; 11. liquid discharge port; 13. observation window; 14. opening; 15. fixed bracket. DETAILED DESCRIPTION

[0028] The technical solutions of the specific implementation modes of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

[0029] like Figure 1-4 A reaction device for photometric colorimetry detection is shown, comprising a reaction device installed on a vertical panel, the reaction device comprising a reaction main unit, a detection unit, a liquid inlet unit and a stirring unit, the liquid inlet unit independently performs sample liquid transportation, reagent titration and pure water cleaning as needed, the solution in the reaction main unit is stirred by the stirring unit to accelerate solution mixing, and the sample liquid concentration in the reaction main unit is detected in the detection unit, thereby achieving the purpose of sample liquid concentration detection.

[0030] The reaction main unit includes a reaction cup holder 2, and a reaction cup 1 made of transparent quartz glass is placed in the cavity of the reaction cup holder 2. The user can observe the color of the solution inside the reaction cup 1. A cup holder cover 5 is installed above the reaction cup holder 2, and the reaction cup holder 2 and the cup holder cover 5 are both made of opaque plastic material to prevent the external light source from entering and affecting the accuracy of the detection. In order to facilitate the observation of the color of the solution inside the reaction cup 1, an observation window 13 is left on the front end surface of the reaction cup holder 2, and a detachable and opaque window cover is installed at the observation window 13, and the window cover is also made of opaque plastic material.

[0031] The stirring unit includes a stirrer bracket 9 arranged at the bottom of the reaction cup holder 2, and a groove portion is arranged on the stirrer bracket 9, and a magnetic stirrer 8 is arranged in the groove portion. The magnetic stirrer 8 cooperates with a magnetic stirring rotor placed inside the reaction cup 1. The magnetic stirring rotor includes a magnetic rotor, and the magnetic rotor is coated with a corrosion-resistant polytetrafluoroethylene layer. Under the action of the magnetic stirrer, the magnetic stirring rotor stirs the solution in the reaction cup 1. In order to fix the magnetic stirrer,

[0032] A bottom cover is provided above the groove portion, and the bottom cover fixes the magnetic stirrer in the groove portion by screws. The bottom cover completes the limit fixation of the magnetic stirrer, and the fixation of the magnetic stirrer requires the bottom cover to fix its four corners. While ensuring that the magnetic stirrer is fixed, in order to better improve the stirring effect, a circular hole is provided in the center of the bottom cover, the purpose of which is to reduce the medium between the magnetic stirrer and the magnetic stirring rotor and improve the stirring sensitivity.

[0033] The detection unit includes a light source emitting part 3 and a light source signal collecting part 4. Two openings 14 arranged on opposite sides are provided on the bottom side wall of the reaction cup holder 2. The light source emitting part 3 and the light source signal collecting part 4 are respectively embedded in the two openings 14. The light source emitting part 3 and the light source signal collecting part 4 can complete the detection as long as the light source signal detection point is below the liquid surface. The light source emitting part 3 and the light source signal collecting part 4 are arranged at the bottom of the reaction cup holder 2 so that the detection can be completed with less solution. If there is less solution, the detection can be completed faster and the detection time can be shortened. The opposite side setting can be used to allow the light source emitted by the light source emitting part 3 to illuminate the solution in the reaction cup 1 and send the light intensity signal to the light source signal collecting part 4, thereby improving the detection sensitivity.

[0034] The liquid inlet unit includes a plurality of liquid inlet hard tubes 7, each of which is connected to the liquid inlet through hole provided on the cup seat cover 5, and the liquid inlet hard tube 7 is made of PTFE material with a diameter of 3 mm. The liquid inlet hard tube 7 is provided with an inverted cone type ferrule joint 6, which is fixed to the liquid inlet through hole. Different reagents are required for titration during the detection process, and the setting of multiple liquid inlet hard tubes is to avoid the problem of cross contamination when different reagents are used with one reagent.

[0035] The reaction cup adopts a cylindrical structure, an overflow port 10 is provided on the upper curved wall of the reaction cup 1, and a drainage port 11 is provided on the bottom curved wall of the reaction cup 1. The drainage port 10 and the overflow port 11 are located on the same plane. The rear end surface of the reaction cup holder 2 is provided with two through holes, which are respectively used for the drainage port 10 and the overflow port 11 to pass through. The drainage port 10 is provided on the bottom curved wall of the reaction cup 1 to realize the complete discharge of the solution in the reaction cup 1. The overflow port 11 is provided to prevent the solution from overflowing and corroding the reaction device.

[0036] In order to ensure stability during the detection process, a fixing bracket 15 is further installed on the rear end surface of the reaction cup holder 2, and the fixing bracket 15 fixes the reaction cup holder 2 on the vertical panel.

[0037] like Figure 1 , Figure 2 and Figure 5 As shown, a detection method of a reaction device for photometric colorimetric detection, the detection method of the reaction device comprises the following steps:

[0038] S1: Determine the substance to be tested in the sample solution, determine the color developer that chemically reacts with the substance to be tested to produce a color change in the solution, determine the monochromatic light based on the relationship between the color of the solution and the color of the absorbed light, and select the monochromatic light of appropriate wavelength; for example, KMnO4 solution appears purple-red under white light, because when white light passes through the solution, most of the green light is absorbed, while all other colors can pass through. In the transmitted light, except for purple-red, all other colors can complement each other to form white, so the KMnO4 solution appears purple-red. Similarly, the CuSO4 solution can absorb yellow light, so the solution appears blue. It can be seen from this that the color of the colored solution is the complementary color of the color of the absorbed light. Therefore, the color produced after the chemical reaction between the substance to be tested and the color developer is determined according to the color. Figure 5 To select the monochromatic light to be absorbed.

[0039] S2: The sampling liquid and pure water are respectively discharged into the reaction cup 1 through a plurality of liquid inlet hard tubes 7, and the reaction cup 1 is rinsed, and then discharged from the discharge port 11 at the bottom curved wall of the reaction cup 1 to ensure that there are no other substances in the reaction cup 1 that may cause inaccurate data detection for concentration detection.

[0040] S3: The sampling liquid is discharged into the reaction cup 1 through the liquid inlet hard tube 7, so that the liquid level of the sampling liquid is above the light source signal detection line. The light source signal is sent from the light source emitting unit 3 to the light source signal collecting unit 4. Of course, a certain height is left between the liquid level of the sampling liquid and the plane where the overflow port 10 is located, so that the solution will not be discharged from the overflow port 10 during the titration of the color developer.

[0041] S4: The developer is titrated through another liquid inlet hard tube 7, and the mathematical expression A=Kcb of the Lambert-Beer law is used for calculation, where A is the absorbance, that is, the degree of absorption of monochromatic light when it passes through the solution, calculated based on the incident light intensity of the light source emitting part and the incident light intensity received by the light source signal collecting part, K ​​is the absorption coefficient, which is a constant for the same substance and incident light of a certain wavelength, b is the optical path, that is, the distance of the light source from one end to the other end of the reaction cup, and the concentration of the substance to be tested C is calculated.

[0042] S5: During the titration process of the color developer, the number of titration steps and the calculated concentration are used to generate several groups of data and filled in the XY axis, where the X axis is the number of titration steps and the Y axis is the concentration of the substance to be tested. The data are connected in sequence to find the titration end point, which is the maximum concentration of the substance to be tested. The titration end point is determined according to the slope value, that is, the mutation point. Therefore, after a certain mass of the substance to be tested reacts chemically with the color developer, the color developer added later cannot react further. The titration end point is the chemical variable end point of the chemical reaction. The titration end point detection is more accurate in measuring the concentration of the substance.

[0043] S6: Record the number of titration steps of the developer at the titration endpoint, and calculate using the formula ST1= K1*R1, where R1 is the number of titration steps at the titration endpoint and K1 is the known slope value in the XY axis, thereby obtaining the concentration value of the substance to be tested in ST1 and completing the entire detection process.

[0044] It should be noted that some chemical reaction processes need to react under acidic or alkaline conditions, which can be achieved by adding acidic or alkaline solutions that do not chemically react with the analyte.

[0045] The reaction device of the present invention is used in a titration analysis instrument, and the control unit and the display unit in the titration analysis instrument realize intelligent control and management of the reaction device of the present invention.

[0046] The working principle of the present invention is as follows: according to different parameters to be measured and different titration chemical reactions, corresponding absorption curves are drawn and the best absorption wavelength is selected, because the best absorption wavelength can obtain a larger absorbance even when the content of the measured substance is low, so the sensitivity of the analysis can be higher. When the titration reaction reaches the vicinity of the chemical variable point, the light intensity value of the absorption wavelength will have an obvious mutation, and the light intensity value of the absorption wavelength during the entire titration process is recorded. The concentration of the sample solution during the titration process is calculated using the formula A=Kcb through the Lambert-Beer law, and an XY coordinate is established, with the X axis being The titration steps, the Y axis is the concentration of the sample solution, and the corresponding data is filled into the XY coordinates to generate a curve, so as to determine the mutation point of the light intensity value in the entire titration process. The mutation point is determined by the slope value. This mutation point is the chemical variable point of the titration reaction, the titration end point, the titration end point is the sampling solution and the color developer produce a chemical reaction and the color change no longer increases significantly. The titration end point is the peak of the curve. The titration end point detection accuracy is more accurate. At the titration end point, the titration steps R1 are counted, and the titration steps are calculated. Finally, the concentration of the sample solution is obtained using the formula ST1= K1*R1. K1 is the slope of the curve generated in the known XY coordinates, and the concentration of ST1 is obtained.

[0047] The preferred specific implementation modes and embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes and embodiments, and various changes can be made within the knowledge scope of those skilled in the art without departing from the concept of the present invention.

Claims

1. A reaction device for photometric colorimetry detection, comprising a reaction device mounted on a vertical panel, characterized in that: The reaction device comprises a reaction main unit, a detection unit, a liquid inlet unit and a stirring unit. The reaction main unit comprises a reaction cup holder, and a reaction cup made of transparent quartz glass is placed in the cavity of the reaction cup holder. A cup holder cover is installed above the reaction cup holder. The stirring unit comprises a stirrer bracket arranged at the bottom of the reaction cup holder, the stirrer bracket is provided with a groove portion, a magnetic stirrer is arranged in the groove portion, and the magnetic stirrer cooperates with a magnetic stirring rotor placed in the reaction cup; The detection unit comprises a light source emitting part and a light source signal collecting part. The bottom side wall of the reaction cup holder is provided with two openings arranged on opposite sides, and the two openings are respectively embedded with the light source emitting part and the light source signal collecting part. The light source emitted by the light source emitting part illuminates the solution in the reaction cup and sends a light intensity signal to the light source signal collecting part. The liquid inlet unit comprises a plurality of liquid inlet hard pipes, each of which is respectively connected to a liquid inlet through hole provided on the cup seat cover; The reaction cup adopts a cylindrical structure, an overflow port is provided on the upper curved wall of the reaction cup, and a liquid discharge port is provided on the bottom curved wall of the reaction cup; The drain port and the overflow port are located on the same plane; The rear end surface of the reaction cup holder is provided with two through holes, which are used for the passage of the discharge port and the overflow port respectively; A fixing bracket is also installed on the rear end surface of the reaction cup holder, and the fixing bracket fixes the reaction cup holder on the vertical panel; The detection method of the reaction device comprises the following steps: S1: Determine the substance to be tested in the sample solution, determine the color developer that chemically reacts with the substance to be tested to produce a solution color change, determine the monochromatic light according to the relationship between the color of the solution and the color of the absorbed light, and select the monochromatic light of appropriate wavelength; S2: The sample liquid and pure water are respectively discharged into the reaction cup through a plurality of liquid inlet hard tubes, and the reaction cup is rinsed, and then discharged from the discharge port at the bottom curved wall of the reaction cup; S3: The sample liquid is discharged into the reaction cup through the liquid inlet hard tube to ensure that the liquid level of the sample liquid is above the light source signal detection line, and the light source signal is sent from the light source transmitting unit to the light source signal collecting unit; S4: Titrate the developer through another liquid inlet hard tube, and use the mathematical expression of Lambert-Beer's law A=Kcb to calculate, where A is the absorbance, that is, the degree of absorption of monochromatic light when it passes through the solution, calculated according to the incident light intensity of the light source emitting part and the incident light intensity received by the light source signal collecting part, K ​​is the absorption coefficient, which is a constant for the same substance and incident light of a certain wavelength, b is the optical path, that is, the distance from one end of the light source to the other end of the reaction cup, and the concentration of the substance to be tested C is calculated; S5: During the titration process, the developer generates several sets of data based on the number of titration steps and the calculated concentration and fills them into the XY axis, where the X axis is the number of titration steps and the Y axis is the concentration of the substance to be measured. The data are connected in sequence to find the titration end point, which is the maximum value of the concentration of the substance to be measured. The titration end point is determined to be the mutation point based on the slope value; S6: Record the number of steps of the developer titration at the titration endpoint, and calculate using the formula ST1=K1*R1, where R1 is the number of steps at the titration endpoint and K1 is the known slope value in the XY axis, thereby obtaining the concentration value of the substance to be tested in ST1 and completing the entire detection process.

2. A reaction device for photometric colorimetric detection according to claim 1, characterized in that: The reaction cup seat and the cup seat cover are both made of opaque plastic material.

3. A reaction device for photometric colorimetric detection according to claim 2, characterized in that: An observation window is left on the front end surface of the reaction cup holder, and a detachable and light-proof window cover is installed at the observation window.

4. A reaction device for photometric colorimetric detection according to claim 1, characterized in that: The liquid inlet hard tube is made of PTFE material, and its diameter is 3mm. An inverted cone type ferrule joint is provided on the outside of the liquid inlet hard tube, and the ferrule joint is fixed on the liquid inlet through hole.

Images