Synthesis method of Schiff base ligand and application of Schiff base ligand in detection of Al < 3 + > content in jellyfish
By synthesizing Schiff base ligand and using its fluorescence enhancement effect on Al3+, the problem of detecting aluminum content in jellyfish is solved, and the detection results with high sensitivity and accuracy are achieved, providing important experimental value for food safety.
Patent Information
- Application Number
- CN202411735625.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-03-11
AI Technical Summary
The prior art is difficult to efficiently and accurately detect the content of aluminum in food, especially in jellyfish products. Exceeding the aluminum content may pose a threat to human health.
By synthesizing a Schiff base ligand, the ligand is based on the reaction of naphthaldehyde and triazole, and using the significant fluorescence enhancement effect of Al3+ ions on the Schiff base ligand, it is used as a fluorescent probe to detect the Al3+ content in jellyfish products.
It has achieved high sensitivity detection of Al3+ content in jellyfish, high spiking recovery rate, accurate detection results, and important experimental value for food safety.
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Figure CN119591554A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of aluminum content detection, and in particular to a method for synthesizing a Schiff base ligand and its application in detecting Al in jellyfish. 3+ Application of content. Background Art
[0002] Food safety is an issue concerning people's livelihood. Excessive aluminum content in food can easily lead to excessive intake of aluminum and cause irreversible damage to the body. Especially in the context of the Internet age, people have increasingly diverse ways to acquire new knowledge and access information, and are gradually aware of the hazards of excessive aluminum intake. Strengthening the detection of aluminum content in food will help prevent foods with excessive aluminum content from entering the circulation market. Summary of the invention
[0003] In view of this, the purpose of this application is to provide a method for synthesizing a Schiff base ligand and its application in detecting Al in jellyfish 3+ Application of content, based on the synthesis of Schiff base ligands from naphthaldehyde and triazole, based on Al 3+ The Schiff base ligand is used as a fluorescent probe to detect Al in jellyfish products. 3+ According to the detection results, the fluorescent probe is effective for Al in jellyfish. 3+ It has high sensitivity, and the spike recovery rate shows that the test results are highly accurate, providing important experimental value in the field of food environment.
[0004] The present application provides a method for synthesizing a Schiff base ligand, the method comprising:
[0005] S1a, using an analytical balance, weigh 3-amino-5-mercapto-1,2,4-triazole and 2-hydroxy-1-naphthaldehyde in a molar ratio of 1:1, and put them in a round-bottom flask;
[0006] S1b, continue to add a stirrer, ethanol and 0.03 mL of glacial acetic acid into the round-bottom flask to obtain a mixed solution; wherein the concentration of the raw materials in the round-bottom flask is 0.4 mol / L;
[0007] S1c, heating the mixed solution to react for 8 to 10 hours by reflux, and then removing the solvent by rotary evaporation to obtain a reaction product;
[0008] S1d. The reaction product is washed with ethanol and then dried to obtain a Schiff base ligand.
[0009] Furthermore, the initial color of the mixed solution in step S1b is an off-white turbid liquid. After reacting for 2 hours by the heating reflux method in step S1c, the color of the mixed solution is an orange-yellow turbid liquid.
[0010] Furthermore, the yield of the Schiff base ligand in step S1d is 85%.
[0011] The present application also provides a method for detecting Al in jellyfish based on Schiff base ligands. 3+ The method comprises:
[0012] S4a, taking 0.5 g of the jellyfish product to be tested and performing pretreatment to obtain a treated liquid;
[0013] S4b, adding 0.6 g of HEPES buffer to the treated solution to prepare 250 mL of the sample solution to be tested with a concentration of 10 mmol / L;
[0014] S4c, add 3 mL of the sample solution to be tested into a 1 cm wide quartz cuvette with four sides transparent to light, take 60 μL of the Schiff base ligand solution with a concentration of 1 mmol / L and add it to the sample solution to be tested;
[0015] S4d, performing fluorescence spectrum test on the sample solution to be tested after adding the Schiff base ligand solution to obtain the fluorescence value of the sample to be tested;
[0016] S4e, based on the regression curve of the fluorescence value of the sample to be tested and the fluorescence value of the standard sample, the Al 3+ content, in order to determine the Al content in jellyfish 3+ Whether the content exceeds the standard.
[0017] Furthermore, the fluorescence value regression curve of the standard sample is drawn by the following steps:
[0018] S5a, take an international aluminum ion solution with a concentration of 1g / L and a HEPES buffer solution with a concentration of 10mmol / L to prepare standard solutions with a concentration gradient of 0, 0.2, 0.4, 0.6, 0.8, 1.0, and 2.0mg / L, respectively, and shake well;
[0019] S5b, according to the concentration gradient, add 3 mL of the standard solution to a 1 cm wide, four-sided transparent quartz cuvette, take 60 μL of a 1 mmol / L Schiff base ligand solution and add it to the standard solution, and shake well;
[0020] S5c. Perform fluorescence spectrum test on the standard solution after adding the Schiff base ligand solution, obtain the fluorescence value of the standard sample as the concentration changes, and draw a fluorescence value regression curve of the standard sample.
[0021] Furthermore, the solvent of the Schiff base ligand solution is DMF.
[0022] Furthermore, the Al content of the sample to be detected is detected based on the regression curve of the fluorescence value of the sample to be detected and the fluorescence value of the standard sample.3+ Content, including:
[0023] Calculate the concentration of the sample to be tested based on the regression curve of the fluorescence value of the sample to be tested and the fluorescence value of the standard sample;
[0024] By Al 3+ The quantitative equation for calculating Al 3+ The content.
[0025] Furthermore, the parameters of the fluorescence spectrum test are set as follows: the excitation wavelength is 342 nm, the emission wavelength is 440 nm, the excitation bandwidth is 10 nm, the emission bandwidth is 10 nm, and the gain is medium.
[0026] The present application provides a method for synthesizing a Schiff base ligand and its application in detecting Al in jellyfish 3+ Application of content, based on the synthesis of Schiff base ligands from naphthaldehyde and triazole, based on Al 3+ The Schiff base ligand is used as a fluorescent probe to detect Al in jellyfish products. 3+ According to the detection results, the fluorescent probe is effective for Al in jellyfish. 3+ It has high sensitivity, and the spike recovery rate shows that the test results are highly accurate, providing important experimental value in the field of food environment. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 A schematic diagram of the synthesis route of the Schiff base ligand provided in the examples of the present application is shown;
[0028] Figure 2 The nuclear magnetic resonance hydrogen spectrum of the Schiff base ligand provided in the examples of the present application is shown;
[0029] Figure 3 shows the mass spectrum of the Schiff base ligand provided in the examples of the present application;
[0030] Figure 4 The fluorescence response diagram of the Schiff base ligand provided in the examples of the present application and 16 metal ions is shown;
[0031] Figure 5 A histogram showing fluorescence changes of the Schiff base ligand and 16 metal ions provided in the examples of the present application is shown;
[0032] Figure 6 The fluorescence value regression curve of the standard sample provided in the example of the present application is shown. DETAILED DESCRIPTION
[0033] In order to make the purpose, technical solution and advantages of the technical solution more clear, the technical solution is further described in detail below in conjunction with specific implementation methods. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the technical solution.
[0034] Example 1: Synthesis of Schiff base ligand
[0035] See also Figure 1 , Figure 1 The figure shows a schematic diagram of the synthesis path of the Schiff base ligand provided in the examples of the present application. Figure 1 As shown, the Schiff base ligand is synthesized based on naphthaldehyde and triazole, specifically:
[0036] Step 101: Use an analytical balance to weigh 0.7 g of 3-amino 5-mercapto-1,2,4-triazole and 1.0 g of 2-hydroxy-1-naphthaldehyde, respectively, and place them in a round-bottom flask.
[0037] Step 102: Continue to add a stirring bar, 15 mL of ethanol and 0.03 mL of glacial acetic acid into the round-bottom flask to obtain a mixed solution; wherein the concentration of the raw materials in the round-bottom flask is 0.4 mol / L.
[0038] The initial color of the mixed solution is grayish white turbid liquid.
[0039] In this step, the raw materials refer to 3-amino 5-mercapto-1,2,4-triazole and 2-hydroxy-1-naphthaldehyde.
[0040] Step 103: for the mixed solution, react by heating under reflux for 8 to 10 hours, and then remove the solvent by rotary evaporation to obtain a reaction product.
[0041] Among them, after reacting for 2 hours using the heating reflux method, the color of the mixed solution appeared to be an orange-yellow turbid liquid.
[0042] Step 104: Wash the reaction product with ethanol and then dry it to obtain a Schiff base ligand.
[0043] The yield of the obtained Schiff base ligand is 85%.
[0044] Compared with the prior art, the above-mentioned synthesis method of the Schiff base ligand uses ethanol solvent instead of the highly toxic methanol solvent, thereby reducing the amount of solvent used, increasing the raw material concentration from 0.1 mol / L to 0.4 mol / L, and shortening the reaction time from 15 h to 8 to 10 h; after the reaction is completed, the solvent is removed by rotary evaporation instead of direct filtration to improve the reaction yield.
[0045] Example 2: Characterization of Schiff base ligands
[0046] The examples of the present application confirm that the synthesized Schiff base ligand is the target product through nuclear magnetic resonance hydrogen spectrum and mass spectrum, specifically:
[0047] See also Figure 2 , Figure 2 The figure shows the nuclear magnetic resonance hydrogen spectrum of the Schiff base ligand provided in the examples of the present application. Figure 2 The analysis was performed to obtain the nuclear magnetic resonance hydrogen spectrum analysis table of the Schiff base ligand as shown in Table 1:
[0048] Table 1. Nuclear magnetic resonance hydrogen spectrum analysis table of Schiff base ligands
[0049]
[0050] Based on the above nuclear magnetic resonance hydrogen spectrum analysis table, it can be determined that the molecular structure of the synthesized Schiff base ligand is consistent with the molecular structure of the target product.
[0051] For further information, see Figure 3 , Figure 3 The mass spectrum of the Schiff base ligand provided in the examples of this application is shown in FIG. Figure 3 As shown, m / z = 271.42 is the quasi-molecular ion peak of the Schiff base ligand [M+H + ]; m / z = 269.53 is the quasi-molecular ion peak of the Schiff base ligand in negative mode [MH + ], based on the mass spectrum analysis, it can be confirmed that the obtained Schiff base ligand is the target product.
[0052] Example 3: Fluorescence spectroscopy test of Schiff base ligand and metal ions
[0053] Prepare Schiff base ligand solution and metal ion aqueous solution:
[0054] Step 201 , dissolving 0.014 g of Schiff base ligand in 50 mL of DMF solvent to prepare a Schiff base ligand solution with a concentration of 1 mmol / L.
[0055] Step 202: prepare 500 mL of a HEPES buffer solution with a concentration of 0.01 mol / L.
[0056] Step 203: For 16 common metal ions, aqueous solutions with a concentration of 0.1 mol / L are prepared respectively.
[0057] Among them, common metal ions include: Cr 3+ 、Ag + 、Cd 2+ , Ca 2+ , Ba 2+ 、Zn 2+ 、Ni 2+ , Pb2+ 、Co 2+ Cr 3+ , K + 、Na + , Hg 2+ Mg 2+ 、Cd 2+ 、Al 3+ .
[0058] Step 204: For Al 3+ Ions were prepared into aqueous solutions with concentrations of 0.01 mol / L, 0.1 mol / L, and 0.1 g / L, respectively.
[0059] Fluorescence test experiment:
[0060] Step 301, setting the parameters of the fluorescence test experiment as follows: the excitation wavelength is 342 nm, the emission wavelength is 440 nm, the excitation slit is 10 nm, the emission slit is 10 nm, and the solvent is 10 mmol / L HEPES buffer solution.
[0061] In this step, the parameters of the fluorescence test experiment are summarized through multiple experiments to make the Schiff base ligand react with Al 3+ There is a good combination of parameters for specific and selective identification.
[0062] Step 302: 1 mmol / L Schiff base ligand solution and 0.01 mol / L HEPES buffer solution are mixed to prepare a solution with a trace amount of DMF at a concentration of 2×10 -5 mol / L mixed solution.
[0063] Step 303: Add 3 mL of the mixed solution to a 1 cm wide, four-side transparent quartz cuvette to perform fluorescence spectrum testing to obtain a reference group fluorescence spectrum.
[0064] Step 304: Use a microsyringe to add the aqueous solutions of metal ions obtained in steps 203 and 204 to the mixed solution, shake well, and then perform fluorescence spectrum test to obtain fluorescence spectra of the experimental groups.
[0065] Step 305: Observe the changes in the curves of the fluorescence spectra of the reference group and the fluorescence spectra of the experimental group.
[0066] In this step, see Figure 4 , 5 , Figure 4 The fluorescence response diagram of the Schiff base ligand and 16 metal ions provided in the examples of this application is shown in FIG. Figure 5 This is a histogram of the fluorescence changes of Schiff base ligands and 16 metal ions provided in the examples of this application. Figure 4 , 5It can be seen that among the 16 metal ions, only Al 3+ Metal ions have a significant fluorescence enhancement effect on Schiff base ligands, while other ions have a weaker fluorescence change or almost no response.
[0067] In view of this, the fourth embodiment of the present application is based on Al 3+ The significant fluorescence enhancement effect of metal ions on Schiff base ligands can be used as fluorescent probes to detect Al in jellyfish products. 3+ Whether the content exceeds the standard.
[0068] Embodiment 4:
[0069] According to my country's "GB2760-2024 Food Safety National Standard for the Use of Food Additives", the residual amount of aluminum is ≤500mg / kg. Combined with the amount used in this experiment, it can be calculated that the aluminum content in jellyfish is ≤500mg / kg, which means that the aluminum content of this brand of product does not exceed the standard.
[0070] The present invention provides a method for detecting Al in jellyfish based on Schiff base ligands. 3+ Methods of content, including:
[0071] Step 401, pre-treating the jellyfish product to be tested to obtain a treated liquid;
[0072] In the specific implementation, the treatment liquid is obtained by the following steps:
[0073] Step 4011, taking 0.5 g of the crushed instant jellyfish sample, adding 50 mL of 1.0% nitric acid solution by volume, vortexing for 1 min, ultrasonicating at 25° C. for 10 min, centrifuging for 5 min, and transferring the upper clear liquid to the 401 beaker;
[0074] Step 4012, continue to add 50mL of 1.0% nitric acid solution into the centrifuge tube, repeat the centrifugation, transfer the upper clear liquid to the 401 beaker, repeat twice to obtain the treated liquid in the 401 beaker.
[0075] Step 402, add 0.60 g of HEPES to the treated solution, stir to dissolve, transfer to a 250 mL volumetric flask, fix the volume, and prepare a sample solution to be tested with a HEPES concentration of 10 mmol / L.
[0076] Step 403 , add 3 mL of the sample solution to be detected into a 1 cm wide quartz cuvette with four sides transparent to light, and add 60 μL of a Schiff base ligand solution with a concentration of 1 mmol / L into the sample solution to be detected.
[0077] Step 404 , performing a fluorescence spectrum test on the sample solution to be tested after adding the Schiff base ligand solution to obtain the fluorescence value of the sample to be tested.
[0078] The parameters of the fluorescence spectrum test are set as follows: the excitation wavelength is 342 nm, the emission wavelength is 440 nm, the excitation bandwidth is 10 nm, the emission bandwidth is 10 nm, and the gain is medium.
[0079] Step 405: Based on the regression curve of the fluorescence value of the sample to be detected and the fluorescence value of the standard sample, the Al 3+ content, in order to determine the Al content in jellyfish 3+ Whether the content exceeds the standard.
[0080] In the specific implementation, the Al content of the sample to be tested is detected by the following steps: 3+ content:
[0081] Step 4051: Calculate the concentration of the sample to be detected based on the regression curve of the fluorescence value of the sample to be detected and the fluorescence value of the standard sample.
[0082] The fluorescence value regression curve of the standard sample is drawn by the following steps:
[0083] Step 501: Take an international aluminum ion solution with a concentration of 1 g / L and a HEPES buffer solution with a concentration of 10 mmol / L to prepare standard solutions with concentration gradients of 0, 0.2, 0.4, 0.6, 0.8, 1.0, and 2.0 mg / L, and shake well.
[0084] Step 502 , according to the concentration gradient, add 3 mL of the standard solution to a 1 cm wide, four-sided light-transmissive quartz cuvette, take 60 μL of a 1 mmol / L Schiff base ligand solution and add it to the standard solution, and shake well.
[0085] The solvent of the Schiff base ligand solution is DMF.
[0086] Step 503 : Perform fluorescence spectrum test on the standard solution after adding the Schiff base ligand solution, obtain the fluorescence value of the standard sample as the concentration changes, and draw a fluorescence value regression curve of the standard sample.
[0087] In this step, see Figure 6 , Figure 6 Shown is the fluorescence value regression curve of the standard sample provided in the examples of the present application. Figure 6 The calibration equation of the standard sample shown is y=58.991χ+24.405, the correlation coefficient is 0.9981, and the linear range is 0-2.0 mg / L.
[0088] Step 4052: Through Al 3+The quantitative equation for calculating Al 3+ The content.
[0089] In this step, Al 3+ The quantitative expression of can be expressed as:
[0090]
[0091] Where, ω is the aluminum content of the sample, mg / kg; C is the Al content in the sample solution to be tested, mg / kg; 3+ Concentration, mg / L; V1 is the volume of the sample solution to be tested, mL; m is the sample sampling amount, g.
[0092] Embodiment 5
[0093] In order to confirm the detection of Al in jellyfish products based on Schiff base ligands provided in this application 3+ The effectiveness of the method to determine whether the content of jellyfish exceeds the standard was investigated by Al 3+ Content detection, specific:
[0094] Take 0.5 g of two brands of instant jellyfish products (marked as samples 1 and 2) and perform pretreatment according to step 401 to obtain a treatment solution; add 0.6 g of HEPES buffer respectively and prepare 250 mL of the sample solution to be tested (10 mmol / L HEPES) according to step 402; take 3 mL of the sample solution to be tested and add it to a cuvette with four sides transparent to light, add 60 μL of a Schiff base ligand solution (DMF solvent) with a concentration of 1 mmol / L, and then put it into a fluorescence tester for detection; substitute the fluorescence value of the sample to be tested into the formula in step 4052 for calculation to determine the Al 3+ Whether the content exceeds the standard.
[0095] Here, please refer to the test results of the samples to be tested shown in Table 2. As shown in Table 2, the fluorescence value of the sample 1 to be tested is 67.90 au, and the concentration of the sample 1 to be tested is calculated to be 0.74 mg / L based on the calibration equation of the standard sample; the fluorescence value of the sample 2 to be tested is 121.90 au, and the concentration of the sample 2 to be tested is calculated to be 1.65 mg / L based on the calibration equation of the standard sample.
[0096] Table 2. Test results of samples to be tested
[0097]
[0098]
[0099] Further, based on the above Al 3+ The quantitative expression can be used to calculate the aluminum content of samples 1 and 2 to be tested:
[0100] The aluminum content of the sample 1 to be tested is It shows that the aluminum content of the sample 1 to be tested does not exceed the standard.
[0101] The aluminum content of the sample 2 to be tested is It shows that the aluminum content of sample 2 to be tested exceeds the standard.
[0102] In addition, in order to verify the accuracy of the test results, the example of the present application also calculated the spiked recovery rates of samples 1 and 2 to be tested, specifically:
[0103] First, after adding 0.2 mg / L of standard solution to the original solution, the solution was placed in a fluorescence tester for detection to obtain the corresponding fluorescence value. Secondly, the concentrations of the samples 1 and 2 to be tested after adding 0.2 mg / L of standard solution were calculated based on the calibration equation of the standard sample. The specific values are shown in Table 2. Finally, the spiked recovery rates of the samples 1 and 2 to be tested were calculated by the following method:
[0104] Recovery rate of spiked sample 1:
[0105] Recovery rate of spiked sample 2:
[0106] Among them, the spike recovery rate shows that the test results are highly accurate, providing important experimental value in the field of food environment.
[0107] From the above analysis, it can be concluded that the aluminum content in jellyfish sample 1 is 370 mg / kg, and the spiked recovery rate is 120%; the aluminum content in jellyfish sample 2 is 825 mg / kg, and the spiked recovery rate is 105%. This shows that the aluminum content of sample 1 does not exceed the standard, while the aluminum content of sample 2 exceeds the standard, and the test results for excessive aluminum content are more accurate.
[0108] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, many changes can be made in the specific implementation methods and application scopes based on the ideas of the present technical content. As long as these changes do not deviate from the concept of the present invention, they all fall within the scope of protection of this patent.
Claims
1. A method for synthesizing a Schiff base ligand, characterized in that: The synthesis method comprises: S1a, using an analytical balance, weigh 3-amino-5-mercapto-1,2,4-triazole and 2-hydroxy-1-naphthaldehyde in a molar ratio of 1:1, and place them in a round-bottom flask; S1b, continue to add a stirrer, ethanol and 0.03 mL of glacial acetic acid into the round-bottom flask to obtain a mixed solution; wherein the concentration of the raw materials in the round-bottom flask is 0.4 mol / L; S1c, heating the mixed solution under reflux for 8 to 10 hours, and then removing the solvent by rotary evaporation to obtain a reaction product; S1d. The reaction product is washed with ethanol and then dried to obtain a Schiff base ligand.
2. The method according to claim 1, characterized in that The initial color of the mixed solution in step S1b is an off-white turbid liquid. After reacting for 2 hours by the heating reflux method in step S1c, the color of the mixed solution is an orange-yellow turbid liquid.
3. The method according to claim 1, characterized in that The yield of the Schiff base ligand in step S1d is 85%.
4. A method for detecting Al in jellyfish based on Schiff base ligands 3+ The method for preparing the composition is characterized in that The method comprises: S4a, taking 0.5 g of the jellyfish product to be tested and performing pretreatment to obtain a treated liquid; S4b, adding 0.6 g of HEPES to the treatment solution to prepare 250 mL of a sample solution to be tested with a concentration of 10 mmol / L HEPES; S4c, add 3 mL of the sample solution to be tested into a 1 cm wide quartz cuvette with four sides transparent to light, take 60 μL of a Schiff base ligand solution with a concentration of 1 mmol / L and add it to the sample solution to be tested; S4d, performing fluorescence spectrum test on the sample solution to be tested after adding the Schiff base ligand solution to obtain the fluorescence value of the sample to be tested; S4e, based on the regression curve of the fluorescence value of the sample to be tested and the fluorescence value of the standard sample, the Al 3+ content, in order to determine the Al content in jellyfish 3+ Whether the content exceeds the standard.
5. The method according to claim 4, characterized in that Draw the fluorescence value regression curve of the standard sample by the following steps: S5a, take an international aluminum ion solution with a concentration of 1g / L and a HEPES buffer solution with a concentration of 10mmol / L to prepare standard solutions with a concentration gradient of 0, 0.2, 0.4, 0.6, 0.8, 1.0, and 2.0mg / L, respectively, and shake well; S5b, according to the concentration gradient, add 3 mL of the standard solution to a 1 cm wide, four-sided transparent quartz cuvette, take 60 μL of a 1 mmol / L Schiff base ligand solution and add it to the standard solution, and shake well; S5c. Perform fluorescence spectrum test on the standard solution after adding the Schiff base ligand solution, obtain the fluorescence value of the standard sample as the concentration changes, and draw a fluorescence value regression curve of the standard sample.
6. The method according to claim 4 or 5, characterized in that The solvent of the Schiff base ligand solution is DMF.
7. The method according to claim 4, characterized in that The Al content of the sample to be detected is detected based on the regression curve of the fluorescence value of the sample to be detected and the fluorescence value of the standard sample. 3+ Content, including: Calculate the concentration of the sample to be tested based on the regression curve of the fluorescence value of the sample to be tested and the fluorescence value of the standard sample; By Al 3+ The quantitative equation for calculating Al 3+ The content.
8. The method according to claim 4 or 5, characterized in that The parameters of the fluorescence spectrum test are set as follows: the excitation wavelength is 342 nm, the emission wavelength is 440 nm, the excitation bandwidth is 10 nm, the emission bandwidth is 10 nm, and the gain is medium.