Method for identifying organic Wuchang rice and common Wuchang rice based on electrochemical luminescence
Through the detection method based on electrochemiluminescence, an electrochemiluminescence system of luminol and hydrogen peroxide is used to distinguish organic Wuchang rice from ordinary Wuchang rice, solving the problems of difficulty in distinguishing between high detection costs in the existing technology, and achieving a fast, accurate and simple identification effect.
Patent Information
- Application Number
- CN202510307789.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-14
- Publication Date
- 2025-06-20
AI Technical Summary
The existing technology is difficult to quickly and accurately distinguish organic Wuchang rice from ordinary Wuchang rice, and the traditional testing methods are costly and require professional equipment and technical personnel.
Using electrochemiluminescence detection method, an electrochemiluminescence system of luminol and hydrogen peroxide is used. The amount of hydrogen peroxide consumed by the difference in catalase content in different rice is different, resulting in different degrees of inhibition of electrochemical reactions, thereby distinguishing between organic Wuchang rice and ordinary Wuchang rice.
It achieves a fast, safe and accurate distinction between organic Wuchang rice and ordinary Wuchang rice, and is characterized by simplicity and efficiency.
Smart Images
Figure CN120177579A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of analytical detection, and particularly relates to a method for differentiating organic Wuchang rice and ordinary Wuchang rice based on electrochemiluminescence. Background Art
[0002] Disclosing the information of this background art section is only intended to enhance the overall understanding of the present invention, and it is not necessarily regarded as an admission or any form of implication that this information constitutes the prior art already known to those of ordinary skill in the art.
[0003] As one of the main food crops globally, especially in Asia, the research on rice has important academic and practical significance. Rice is not only an indispensable staple food in people's daily diet but also attracts much attention due to its unique nutritional components and diverse processing and utilization values. Rice is rich in nutrients such as carbohydrates, proteins, vitamins, and minerals, and has the effects of tonifying the middle qi, strengthening the spleen and nourishing the stomach, and moistening the lungs yin. Organic Wuchang rice is not treated with chemical pesticides, chemical fertilizers, and growth regulators during the planting process, so it does not contain chemical residues and is safer to consume. Its nutritional value is usually higher, containing more trace elements such as iron, magnesium, zinc, selenium, and vitamin C, while the content of heavy metals and carcinogenic substances such as nitrates is lower. Currently, there are many problems in the market of passing off inferior goods as superior ones, selling ordinary Wuchang rice as organic Wuchang rice. Usually, the method to distinguish the two is the observation method: the appearance of organic Wuchang rice is usually more natural, with plump and uniform grains and natural color, while ordinary Wuchang rice may show an unnatural luster due to the addition of chemical substances during the processing. However, it is difficult to accurately determine whether the rice is organic only by appearance and smell, and there may be differences in appearance and smell among different varieties of rice. In addition, professional detection equipment and methods can be used to measure the pesticide residues and heavy metal content in rice to determine whether it is organic Wuchang rice. The advantage of this method is that the detection results are relatively accurate, but the disadvantages are that the detection cost is high, and professional equipment and technical personnel are required. Therefore, it is of great significance to develop a simple and rapid method for differentiating organic Wuchang rice and ordinary Wuchang rice. Summary of the Invention
[0004] In order to solve the deficiencies of the existing technologies for differentiating organic Wuchang rice and ordinary Wuchang rice, the object of the present invention is to provide a detection method based on electrochemiluminescence. The differentiation method provided by the present invention is based on the electrochemiluminescence system of luminol and hydrogen peroxide. By using the difference in the content of catalase in different rices, the amount of hydrogen peroxide consumed is different, resulting in different degrees of inhibition of the electrochemical reaction between luminol and hydrogen peroxide, and finally reflected in different reduction rates of luminescence intensity, so as to indirectly distinguish the two rices and achieve the differentiation of organic Wuchang rice and ordinary Wuchang rice.
[0005] To achieve the above object, the present invention provides a method for differentiating organic Wuchang rice and ordinary Wuchang rice based on electrochemiluminescence, comprising the following steps:
[0006] (1) Add PBS buffer solution, luminol solution and hydrogen peroxide solution to the reaction cell in sequence.
[0007] (2) Connect the working electrode, reference electrode and auxiliary electrode to the electrochemiluminescence signal monitoring system, and insert them into the quartz reaction cell containing the reaction solution in step (1). An electrical signal is excited to generate an electrochemiluminescence signal, and the initial electrochemiluminescence signal is recorded.
[0008] (3) Add the supernatant obtained by treating organic Wuchang rice to the reaction cell, and record the electrochemiluminescence signal. Empty the reaction cell, re-add the reaction solution, add the supernatant obtained by treating ordinary Wuchang rice to the reaction cell, record the electrochemiluminescence signal, and then calculate the reduction rate by comparing the differences between the two electrochemiluminescence signals and the initial electrochemiluminescence signal, so as to find the differences between organic Wuchang rice and ordinary Wuchang rice.
[0009] The beneficial effects of the present invention are as follows:
[0010] The present invention adopts a three-electrode system, uses a glassy carbon electrode as the working electrode, an Ag / AgCl electrode as the reference electrode, and platinum as the auxiliary electrode, and uses an electrical signal to excite and generate an electrochemiluminescence signal. Utilize the chemiluminescence reaction of luminol and hydrogen peroxide. Under alkaline conditions, luminol first reacts with hydroxide to form a dianion, and this dianion is then oxidized by the oxygen generated by the decomposition of hydrogen peroxide. The unstable organic peroxide generated decomposes rapidly and releases nitrogen, and at the same time generates excited 3-aminophthalic acid. When the excited 3-aminophthalic acid returns to the ground state, the released energy exists in the form of photons, and the wavelength is in the blue light part of the visible light, thus generating a luminescence phenomenon. The catalase in rice can react with hydrogen peroxide, thereby inhibiting the luminescence reaction of luminol and hydrogen peroxide. The higher the content of catalase, the more hydrogen peroxide is consumed, the more obvious the inhibitory effect on the generated electrochemiluminescence signal, and the higher the reduction rate. Based on this, the correlation between the catalase content of different rices and the reduction rate of electrochemiluminescence signal intensity is established. Using the detection method of the present invention to quickly distinguish organic rice and ordinary rice has the characteristics of safety, accuracy, effectiveness and simplicity. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The attached drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.
[0012] Figure 1Schematic diagram of the organic Wuchang rice and ordinary Wuchang rice used in the present invention
[0013] Figure 2 Equipment diagram used in the present invention
[0014] Figure 3 Schematic diagram of the reaction cell and three - electrode system used in the present invention
[0015] Figure 4 Principle diagram of the reaction between luminol and hydrogen peroxide in the present invention
[0016] Figure 5 Effect of pH on luminescence intensity
[0017] Figure 6 Effect of luminol concentration on luminescence intensity
[0018] Figure 7 Schematic diagram of the inhibition of luminescence intensity by the supernatant after treating organic Wuchang rice and ordinary Wuchang rice Detailed implementation manners
[0019] In view of the deficiencies of the existing methods for identifying organic Wuchang rice and ordinary Wuchang rice, the present invention proposes a method for identifying organic Wuchang rice and ordinary Wuchang rice based on electrochemiluminescence.
[0020] A typical implementation manner of the present invention provides a method for identifying organic Wuchang rice and ordinary Wuchang rice based on electrochemiluminescence, including the following steps:
[0021] (1) Add PBS buffer solution, luminol solution and hydrogen peroxide solution to the reaction cell in sequence.
[0022] (2) Connect the working electrode, reference electrode and auxiliary electrode to the electrochemiluminescence signal monitoring system, and insert them into the quartz reaction cell containing the reaction solution in step (1). An electrochemiluminescence signal is generated by electrical signal excitation, and the initial electrochemiluminescence signal is recorded.
[0023] (3) Add the supernatant treated with organic Wuchang rice to the reaction cell, and record the electrochemiluminescence signal. Empty the reaction cell, re - add the reaction solution, add the supernatant treated with ordinary Wuchang rice to the reaction cell, record the electrochemiluminescence signal, and then calculate the reduction rate by comparing the differences between the two electrochemiluminescence signals and the initial electrochemiluminescence signal, so as to find the differences between organic Wuchang rice and ordinary Wuchang rice.
[0024] The discrimination method provided by the present invention is based on the electrochemiluminescence system of luminol and hydrogen peroxide. By utilizing the difference in the content of catalase in different rice varieties, the amount of hydrogen peroxide consumed is different, resulting in different degrees of inhibition of the electrochemistry reaction between luminol and hydrogen peroxide, and ultimately reflected in different reduction rates of luminescence intensity, thereby indirectly distinguishing the two types of rice and achieving the discrimination between organic rice and ordinary rice. Moreover, as known to the inventors, this is the first time that the electrochemiluminescence method has been applied to the discrimination of organic rice and ordinary rice.
[0025] In some embodiments of this implementation manner, the preparation method of the luminescence reaction solution is as follows: 5 ml of 0.01 M PBS buffer solution, 50 μl of 6 mM luminol solution, and 10 μl of 0.88 M hydrogen peroxide solution are sequentially added to the reaction cell and mixed evenly.
[0026] In some embodiments of this implementation manner, the pH of the PBS buffer solution is 9.0. The pH affects the electrochemiluminescence signal of luminol and hydrogen peroxide. In an acidic environment, the luminescence intensity of luminol is usually low because, under acidic conditions, the structure of the luminol molecule may be damaged or its reaction efficiency with hydrogen peroxide may decrease. While too high a pH may lead to instability of the reaction system. For example, the decomposition rate of hydrogen peroxide may increase, thus affecting the duration of the luminescence reaction. At the same time, too high a pH will also cause the phenomenon of light quenching, resulting in no luminescence signal.
[0027] In some embodiments of this implementation manner, the luminol solution is generally prepared with 0.05 mol / L NaOH solution.
[0028] In some embodiments of this implementation manner, the hydrogen peroxide solution is obtained by diluting the standard 30% hydrogen peroxide solution ten times.
[0029] In some embodiments of this implementation manner, the working electrode is a glassy carbon electrode. When in use, the surface of the electrode needs to be polished, and then ultrasonically cleaned with pure water and ethanol in sequence, and dried to avoid interference with the experiment.
[0030] In some embodiments of this implementation manner, the polishing uses 0.05 μm alumina powder to polish the surface of the glassy carbon electrode. By polishing, the impurities on the surface of the glassy carbon electrode are removed, making the electrode surface have a mirror effect, which is conducive to the progress of the luminescence reaction and reduces interference.
[0031] In some embodiments of this implementation manner, the supernatant is obtained by grinding the rice into dry powder, adding pure water to dissolve it, and then centrifuging.
[0032] In another embodiment of this embodiment, the present invention does not limit the excitation method of the electrochemical luminescence electrical signal, and it is sufficient to be able to excite and generate an electrochemical luminescence signal. In some embodiments, cyclic voltammetry, linear sweep voltammetry, constant potential method, potential step pulse method, etc. are included, preferably cyclic voltammetry. Further preferably, the cyclic voltammetry is: initial point 0V, low potential -0.2V, high potential 0.5V, scanning direction is forward, scanning rate 0.1V / S, scanning segment 4 segments, sampling interval 0.001V, standing time 4S, sensitivity 1.e-006.
[0033] In some examples of this embodiment, the reference electrode is an Ag / AgCl electrode, and the auxiliary electrode is platinum.
[0034] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.
[0035] Example 1
[0036] (1) Extraction of rice supernatant
[0037] After 0.5 g of rice flour was fully mixed with 3 ml of pure water, the mixture was centrifuged at 5000 rpm for 20 min, and the supernatant was taken out for later use.
[0038] (2) Preparation of luminol solution
[0039] 0.0088 g of luminol powder was fully dissolved in 5 ml of pre-prepared 0.05 mol / L NaOH solution to obtain a 10 mM luminol solution, which was then diluted to obtain the required 6 mM luminol solution.
[0040] (3) Preparation of hydrogen peroxide solution
[0041] Take 0.5 ml of 30% standard hydrogen peroxide solution and dilute it 10 times with pure water to obtain 0.88 M hydrogen peroxide solution.
[0042] (4) Preparation of PBS buffer
[0043] Dissolve 7.9g NaCl, 0.2g KCl, 0.24g KH2PO4 and Na2HPO4 in 900ml pure water, add pure water to make up to 1L, and finally adjust the pH of the solution to 9.0 with NaOH solution to obtain 0.01M PBS buffer.
[0044] (5) Identification of organic Wuchang rice and ordinary Wuchang rice using electrochemiluminescence
[0045] Take 5 ml of 0.01 M PBS buffer solution, 50 μl of 6 mM luminol solution and 10 μl of 0.88 M hydrogen peroxide solution in a quartz reaction cell. After inserting the three electrodes connected to the electrochemiluminescence detector into the reaction cell, place it in a closed reaction chamber. Start the software and set the parameters of cyclic voltammetry as described before: initial potential 0 V, low potential -0.2 V, high potential 0.5 V, scanning direction forward, scanning rate 0.1 V / S, 4 scanning segments, sampling interval 0.001 V, standing time 4 S, sensitivity 1.e-006. After setting, record the electrochemiluminescence signal.
[0046] Add the supernatant of organic Wuchang rice to the above reaction cell, record the decrease value of the electrochemiluminescence signal, empty the reaction cell, and perform another set of experiments with the supernatant of ordinary Wuchang rice. Calculate the reduction rate of luminescence intensity for the two types of rice. It can be found that the effect of organic Wuchang rice on reducing the electrochemiluminescence signal is better than that of ordinary Wuchang rice.
[0047] Finally, eight groups of comparative experiments were set up in this invention. After repeating each group of experiments 3 times and taking the average value, it was used to compare the effects of organic Wuchang rice and ordinary Wuchang rice on reducing the electrochemiluminescence signal, and then to determine a unified standard.
[0048] Table 1 Results of eight groups of comparative experiments
[0049] The obtained identification results are as follows: If the reduction effect of a certain Wuchang rice on the electrochemiluminescence signal is within the range of 65 ± 4.9%, then this Wuchang rice is organic Wuchang rice; if the reduction effect of a certain Wuchang rice on the electrochemiluminescence signal is within the range of 55 ± 4.9%, then this Wuchang rice is ordinary Wuchang rice.
[0050] For the structures, devices and operation methods not specifically described and explained in this invention, without special instructions and limitations, experiments are carried out according to the conventional means in the art.
Claims
1. A method for distinguishing organic Wuchang rice from ordinary Wuchang rice based on electrochemiluminescence, characterized in that: The steps include: (1) Add PBS buffer, luminol solution and hydrogen peroxide solution into the reaction pool in sequence. (2) Connecting the working electrode, the reference electrode, and the auxiliary electrode to an electrochemiluminescence signal monitoring system, and inserting them into the quartz reaction cell containing the reaction solution in step (1), exciting the electrochemiluminescence signal with an electrical signal, and recording the initial electrochemiluminescence signal. (3) Add the supernatant treated with organic Wuchang rice to the reaction pool and record the electrochemiluminescence signal. Empty the reaction pool, add the reaction liquid again, add the supernatant treated with ordinary Wuchang rice to the reaction pool, record the electrochemiluminescence signal, and then calculate the reduction rate by comparing the difference between the two electrochemiluminescence signals and the initial electrochemiluminescence signal, and then find the difference between organic Wuchang rice and ordinary Wuchang rice.
2. The method for distinguishing organic Wuchang rice and ordinary Wuchang rice based on electrochemical luminescence as claimed in claim 1, characterized in that, The principle of the chemiluminescent reaction of luminol and hydrogen peroxide: Under alkaline conditions, luminol first reacts with hydroxide to generate a double negative ion (Dianion), which is then oxidized by the oxygen produced by the decomposition of hydrogen peroxide. The unstable organic peroxide generated quickly decomposes and releases nitrogen, while generating excited 3-aminophthalic acid. When the excited 3-aminophthalic acid returns to the ground state, the released energy exists in the form of photons with a wavelength in the blue part of visible light, thereby producing luminescence.
3. The method for distinguishing organic Wuchang rice and ordinary Wuchang rice based on electrochemical luminescence as claimed in claim 1, characterized in that, By adding the treated rice supernatant, the hydrogen peroxide is consumed by the reaction of the catalase contained in the supernatant with hydrogen peroxide, that is, the reactants participating in the luminescence reaction are reduced, thereby achieving the effect of inhibiting the light intensity.
4. The method for distinguishing organic Wuchang rice and ordinary Wuchang rice based on electrochemical luminescence as claimed in claim 1, characterized in that, The added supernatant is obtained by first crushing rice into rice flour, sieving it and sealing it for storage, and then taking it out during the experiment, dissolving it directly and then centrifuging it.
5. The method for distinguishing organic Wuchang rice and ordinary Wuchang rice based on electrochemical luminescence as claimed in claim 1, characterized in that, The catalase content in organic Wuchang rice and ordinary Wuchang rice is different, and the degree of inhibition of the reaction between luminol and hydrogen peroxide is also different, showing different effects on reducing the luminescence intensity.
6. The method for distinguishing organic Wuchang rice and common Wuchang rice based on electrochemical luminescence as claimed in claim 1, characterized in that The concentration of hydrogen peroxide is 0.88M, the concentration of luminol is 6mM, the concentration of PBS buffer is 0.01M, and the pH is 9.
0.
7. The method for distinguishing organic Wuchang rice and ordinary Wuchang rice based on electrochemical luminescence as claimed in claim 1, characterized in that, The electrochemical luminescence signal detection system has the following methods for generating electric signals: cyclic voltammetry, linear sweep voltammetry, chronoamperometry, and chronocoulometry; cyclic voltammetry is preferred.
8. The method for distinguishing organic Wuchang rice and ordinary Wuchang rice based on electrochemical luminescence as claimed in claim 1, characterized in that, The cyclic voltammetry method is as follows: the initial point is 0V, the low potential is -0.2V, the high potential is 0.5V, the scanning direction is forward, the scanning rate is 0.1V / S, the scanning segments are 4 segments, the sampling interval is 0.001V, the standing time is 4S, and the sensitivity is 1.e-006.
9. The method for distinguishing organic Wuchang rice and common Wuchang rice based on electrochemical luminescence as claimed in claim 1, characterized in that, The reference electrode is an Ag / AgCl electrode, the working electrode is a glassy carbon electrode, and the auxiliary electrode is platinum.
10. The method for distinguishing organic Wuchang rice and ordinary Wuchang rice based on electrochemiluminescence as claimed in claim 1, characterized in that: The distinguishing method is to distinguish between the two types of rice by comparing the different reduction rates of the luminous intensity of the two types of rice.