A reverse micelle for extracting capsaicin and its preparation method

Abstract

This invention provides a reverse micelle solution for extracting capsaicin and its preparation method, comprising the following steps: S1: Adding Span 20 and Span 80 to n-hexane, followed by ultrasonic treatment to obtain solution A; S2: Adding NaCl solution to liquid A obtained in step S1 under oscillation and stirring to obtain solution B, centrifuging solution B, and obtaining the supernatant as the reverse micelle solution for capsaicin extraction. The beneficial effects of this invention are: the method of this invention can prepare a transparent and stable reverse micelle solution and achieve capsaicin separation using reverse micelle extraction.

Description

Technical Field

[0001] This invention belongs to the field of reverse micelles, and in particular relates to a reverse micelle for extracting capsaicin and a method for preparing the same. Background Technology

[0002] Capsaicin is the main compound in the capsaicin family, followed by dihydrocapsaicin, nordihydrocapsaicin, and homodihydrocapsaicin. It is estimated that capsaicin and dihydrocapsaicin together account for approximately 90% of the total capsaicin compounds in chili peppers, which are widely used globally in culinary, medicinal, and personal defense pepper spray applications. In addition to its use as an ingredient and nutrient in novel culinary and pharmaceutical formulations, capsaicin is also used to measure the cough threshold after a patient ingests an antitussive. Recent research has expanded the applications of capsaicin to include neurobiological research, weight management, local analgesia, and antibacterial defense.

[0003] Several methods, including Soxhlet extraction, supercritical fluid extraction, microwave-assisted extraction, macroporous adsorption resin method, and high-speed countercurrent chromatography, have been successfully used to extract and separate capsaicin from chili peppers. However, these extraction techniques typically extract capsaicin compounds directly from chili peppers rather than being tailored for fresh weight applications, which may affect the bioactivity of capsaicin. Summary of the Invention

[0004] In view of this, the present invention aims to provide a reverse micelle for extracting capsaicin and a method for preparing the same, in order to solve at least one technical problem in the background art.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A method for preparing reverse micelles for extracting capsaicin includes the following steps:

[0007] S1: Add Span 20 and Span 80 to n-hexane, and then sonicate to obtain solution A;

[0008] S2: Add NaCl solution to liquid A obtained in step S1 under oscillation and stirring conditions to obtain solution B. Centrifuge solution B, and the supernatant is the reverse micelle solution used for extracting capsaicin.

[0009] Furthermore, in step S1, the concentrations of Span 20 and Span 80 are 10–50 mmol / L;

[0010] And / or, the concentration ratio of Span 20 and Span 80 in step S1 is 1:1 to 7:3.

[0011] Furthermore, the ultrasonic power in step S1 is 20 kHz to 60 kHz, and the ultrasonic time is 20 min to 100 min.

[0012] Furthermore, the mass of the NaCl solution added in step S2 is 0.5 to 2 times the mass of liquid A; and / or, the concentration of the NaCl solution added in step S2 is 0.5 mol / L to 2 mol / L.

[0013] Furthermore, in step S2, the temperature of the oscillation and stirring is 20℃~40℃, and the rotation speed is 300 rpm~600 rpm;

[0014] And / or, the centrifugation speed in step S2 is 6000 rpm to 8000 rpm, and the centrifugation time is 10 min to 20 min.

[0015] A method for preparing reverse micelles for extracting capsaicin.

[0016] The above-mentioned method of using reverse micelles includes the following steps:

[0017] A1: The reverse micelle solution was mixed with the waste liquid from the desiccant reaction and extracted. After separation, the upper oil phase was obtained.

[0018] A2: Mix the upper oil phase obtained in step A1 with a solvent to obtain a mixture; extract the mixture, separate the liquid and retain the lower aqueous phase, and obtain capsaicin by evaporation and crystallization of the lower aqueous phase.

[0019] Furthermore, the volume ratio of the desiccant reaction waste liquid to the reverse micelle solution in step A1 is 1:3 to 3:1;

[0020] And / or, the waste liquid from the desiccant removal reaction is extracted with the reverse micelle solution at a pH of 6-11 and a temperature of 20℃-60℃ for 0.5h-2.5h;

[0021] Preferably, the extraction is carried out in a reaction vessel in which the temperature can be accurately controlled, reaching the set temperature of 20℃ to 60℃ within 5 min to 10 min, with a pH value of 6 to 11, and the reaction time is 0.5 h to 2.5 h.

[0022] Furthermore, in step A2, the mass ratio of the upper oil phase to the solvent is 1:1 to 1:5.

[0023] And / or, the solvent is either distilled water or tap water.

[0024] Further, in step A2, the mixture is extracted for 0.5 h to 2.5 h at a pH of 5 to 9 and a temperature of 20 °C to 60 °C, and then separated using a separatory funnel, retaining the lower aqueous phase;

[0025] The extraction reaction was carried out in a reaction vessel with precise temperature control, reaching the set temperature of 20℃ to 60℃ within 5 min to 10 min, with a pH value of 5 to 9, and the reaction time was 0.5 h to 2.5 h.

[0026] Reverse micelles are molecular aggregates composed of nonpolar surfactants and water, serving as both model systems for biofilms and microreactors for chemical and biological reactions. The size of reverse micelles can be readily tuned by stabilizing a polar phase (typically water) within a nonpolar phase. Due to their unique properties in solution, reverse micelles play a crucial role in a wide range of research applications.

[0027] Compared with existing technologies, the reverse micelles for extracting capsaicin and their preparation method described in this invention have the following advantages:

[0028] 1. The method of the present invention can prepare a transparent and stable reverse micelle solution and use reverse micelle extraction to separate capsaicin.

[0029] 2. This invention enables rapid separation of capsaicin through reverse micelle extraction, significantly improving extraction efficiency in a short time. Furthermore, this process is conducted under mild conditions, preventing the degradation of heat-sensitive components such as capsaicin and ensuring the preservation of their biological activity.

[0030] 3. The reverse micelles exhibit specific selectivity, which improves the purity of capsaicin to meet the demand for high-quality products.

[0031] 4. The organic solvents and surfactants in the reverse micelles can be recycled and reused, reducing environmental pollution and production costs, making the method economically feasible while meeting environmental requirements. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 This is a schematic diagram of the full-wavelength scan of the standard solution of the present invention;

[0034] Figure 2 This is a schematic diagram showing the absorbance of the standard solution of the present invention in a 1cm quartz cuvette;

[0035] Figure 3 This is a schematic diagram showing the pre-extraction rates at different pH values ​​according to the present invention;

[0036] Figure 4 This is a schematic diagram showing the pre-extraction rate at different times according to the present invention;

[0037] Figure 5This is a schematic diagram showing the pre-extraction rates at different temperatures according to the present invention;

[0038] Figure 6 This is a schematic diagram of the pre-extraction rate at different oil-water ratios according to the present invention;

[0039] Figure 7 This is a schematic diagram showing the post-extraction rates at different pH values ​​according to the present invention;

[0040] Figure 8 This is a schematic diagram showing the post-extraction rate at different times according to the present invention;

[0041] Figure 9 This is a schematic diagram showing the post-extraction rate at different temperatures according to the present invention. Detailed Implementation

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0043] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0044] The method for preparing reverse micelle solutions and the method for separating capsaicin provided by this invention include the following steps:

[0045] (1) Add Span 20 and Span 80 to n-hexane, and sonicate to obtain solution A;

[0046] (2) Under the condition of shaking and stirring, NaCl solution is added dropwise to liquid A obtained in step (1) to obtain solution B;

[0047] (3) Centrifuge the solution B obtained in step (2) to obtain the supernatant and prepare the reverse micelle solution;

[0048] (4) Mix the reverse micelle solution obtained in step (3) with the desiccant reaction waste liquid, extract for 0.5h to 2.5h under the conditions of pH 6 to 11 and temperature 20℃ to 60℃, separate the liquids using a separatory funnel, and retain the upper oil phase;

[0049] (5) Mix the upper oil phase from step (3) with the solvent to obtain a mixture; extract the mixture for 0.5h to 2.5h at a pH of 5 to 9 and a temperature of 20℃ to 60℃, separate the liquids using a separatory funnel, and retain the lower aqueous phase;

[0050] (6) Collect the lower aqueous phase from step (5) and evaporate and crystallize it to obtain capsaicin.

[0051] Example 1: Preparation of reverse micelles and separation of capsaicin.

[0052] The method for preparing the reverse micelle solution and the method for separating capsaicin in this embodiment include the following steps:

[0053] (1) Place n-hexane into a container and sonicate it according to the ratio of Span 20 and Span 80, with a total concentration of 10 mm, which is 1:1. Control the ultrasonic power at 20 kHz and obtain solution A in 20 min.

[0054] (2) Under the conditions of shaking and stirring at a speed of 300 rpm and a temperature of 20℃, add 0.5 times the mass of a 0.5 mol / L NaCl solution dropwise to the liquid A obtained in step (1) to obtain solution B;

[0055] (3) Centrifuge the solution B obtained in step (2) at 6000 rpm for 10 min and take the supernatant to obtain the reverse micelle solution;

[0056] The obtained nanoemulsion had a particle size of 2.486 nm and a PDI (polydispersity index) of 0.135. The measurement method is as follows:

[0057] The average particle size and polydispersity index (PDI) of the samples were determined using a nano-particle size analyzer and a zeta potentiometer (Nano Zetasizer, UK). The samples were aspirated into a four-sided quartz cell, and air bubbles were avoided during sample addition. Water was set as the dispersant, the instrument equilibration time was set to 100 s, the test angle was 173°, and each sample was measured three times.

[0058] The reverse micelle solution obtained in step (3) was placed in a reaction vessel in which the temperature could be accurately controlled. The desiccant reaction waste liquid was added and mixed in a mass ratio of 1:3. The mixture was extracted for 0.5 h at pH 6 and temperature 20°C. The mixture was separated using a separatory funnel to obtain the upper oil phase.

[0059] (5) Place the upper oil phase from step (3) into a reaction vessel where the temperature can be accurately controlled, add solvent in a mass ratio of 1:1 and mix to obtain a mixture; extract the mixture at pH 5 and temperature 20°C for 0.5 h, separate the liquids using a separatory funnel to obtain the lower aqueous phase;

[0060] (6) Collect the lower aqueous phase from step (5) and place it in a dry place to evaporate slowly.

[0061] The specific steps for measuring capsaicin content are as follows:

[0062] Ultraviolet analysis of capsaicin:

[0063] Preparation of Standards: Capsaicin standard (purchased from China National Pharmaceutical Group Chemical Reagent Co., Ltd.) was prepared into a series of standard solutions with different concentrations, including 10 mg / L, 40 mg / L, 60 mg / L, 80 mg / L, and 100 mg / L. The standard solutions were scanned across the entire wavelength range using a UV spectrophotometer, and the desired wavelength was identified by the corresponding peaks. The results are shown below. Figure 1 As shown. A standard curve was constructed by measuring the absorbance of the standard solution in a 1 cm quartz cuvette, and the results are shown below. Figure 2 As shown. The capsaicin content in the unknown extract solution was calculated based on the absorbance values ​​of the known standard solutions. The absorbance of the filtered solution in a 1 cm quartz cuvette was measured using a 280 nm UV spectrophotometer. The capsaicin content in the unknown extract solution was calculated based on the absorbance values ​​of the known standard solutions.

[0064] Step (4) The lower aqueous phase has a concentration of 270.44 mg / L, and the upper oil phase has a concentration of 165.76 mg / L. Step (5) The lower aqueous phase has a concentration of 71.27 mg / L. The capsaicin content in the despication reaction waste liquid is 436.2 mg / L.

[0065] Example 2: Preparation of reverse micelles and separation of capsaicin

[0066] The preparation method of the reverse micelle solution and the capsaicin separation method of this embodiment include the following steps: (1) Hexane is placed in a container and ultrasonically treated according to the ratio of Span 20 and Span 80, with a total concentration of 20 mm and a concentration ratio of 3:2. The ultrasonic power is controlled at 30 kHz and solution A is obtained in 40 min.

[0067] (2) Under the conditions of shaking and stirring at a speed of 400 rpm and a temperature of 30℃, add dropwise an equal mass of 0.7 mol / L NaCl solution to liquid A obtained in step (1) to obtain solution B;

[0068] (3) Centrifuge the solution B obtained in step (2) at 7000 rpm for 15 min and take the supernatant to obtain the reverse micelle solution;

[0069] The resulting nanoemulsion had a particle size of 3.153 nm and a PDI (polydispersity index) of 0.227. The measurement method was the same as in Example 1.

[0070] (4) The reverse micelle solution obtained in step (3) is placed in a reaction vessel in which the temperature can be accurately controlled. The desiccant reaction waste liquid is added and mixed in a mass ratio of 1:2. The mixture is extracted for 1 h at a pH of 7.57 and a temperature of 27.61℃. The mixture is separated using a separatory funnel to obtain the upper oil phase.

[0071] (5) Place the upper oil phase from step (3) into a reaction vessel where the temperature can be accurately controlled, add solvent at a mass ratio of 1.307:1 and mix to obtain a mixture; extract the mixture at pH 7 and temperature 60°C for 1.5 h, separate the liquids using a separatory funnel to obtain the lower aqueous phase;

[0072] (6) Collect the lower aqueous phase from step (5) and place it in a dry place to evaporate slowly.

[0073] The method for determining capsaicin content is the same as in Example 1.

[0074] Step 4: Lower aqueous phase 134.00 mg / L, upper oil phase 302.20 mg / L; Step 5: Lower aqueous phase 175.28 mg / L. The capsaicin content in the desiccant reaction waste liquid was 436.2 mg / L.

[0075] Example 3: Preparation of reverse micelles and separation of capsaicin

[0076] The method for preparing the reverse micelle solution and the method for separating capsaicin in this embodiment include the following steps:

[0077] (1) Place n-hexane into a container and sonicate it according to the ratio of Span 20 and Span 80, with a total concentration of 30 mm and a concentration ratio of 7:3. Control the ultrasonic power at 40 kHz and obtain solution A in 60 min.

[0078] (2) Under the conditions of shaking and stirring at a speed of 500 rpm and a temperature of 40℃, add 1.5 times the mass of a 0.9 mol / L NaCl solution dropwise to the liquid A obtained in step (1) to obtain solution B;

[0079] (3) Centrifuge the solution B obtained in step (2) at 8000 rpm for 20 min and take the supernatant to obtain the reverse micelle solution;

[0080] The resulting nanoemulsion had a particle size of 8.717 nm and a PDI (polydispersity index) of 0.1773. The measurement method was the same as in Example 1.

[0081] (4) The reverse micelle solution obtained in step (3) is placed in a reaction vessel in which the temperature can be accurately controlled. The desiccant reaction waste liquid is added and mixed in a mass ratio of 1:1. Extraction is carried out for 1.5 h at pH 8 and temperature 40℃. The mixture is separated by a separatory funnel to obtain the upper oil phase.

[0082] (5) Place the upper oil phase from step (3) into a reaction vessel where the temperature can be accurately controlled, add solvent in a mass ratio of 1:3 and mix to obtain a mixture; extract the mixture at pH 7 and temperature 40°C for 1.5 h, separate the liquids using a separatory funnel to obtain the lower aqueous phase;

[0083] (6) Collect the lower aqueous phase from step (5) and place it in a dry place to evaporate slowly.

[0084] The method for determining capsaicin content is the same as in Example 1.

[0085] Step 4: Lower aqueous phase 187.57 mg / L, upper oil phase 248.63 mg / L; Step 5: Lower aqueous phase 114.37 mg / L. The capsaicin content in the desiccant reaction waste liquid was 436.2 mg / L.

[0086] Example 4: Preparation of reverse micelles and separation of capsaicin

[0087] The method for preparing the reverse micelle solution and the method for separating capsaicin in this embodiment include the following steps:

[0088] (1) Place n-hexane into a container and sonicate it according to the ratio of Span 20 and Span 80, with a total concentration of 40 mm and a concentration ratio of 4:1. Control the ultrasonic power at 50 kHz and obtain solution A in 80 min.

[0089] (2) Under the conditions of shaking and stirring at a speed of 600 rpm and a temperature of 40℃, add dropwise twice the mass of a 1.1 mol / L NaCl solution to the liquid A obtained in step (1) to obtain solution B;

[0090] (3) Centrifuge the solution B obtained in step (2) at 8000 rpm for 20 min and take the supernatant to obtain the reverse micelle solution;

[0091] The resulting nanoemulsion had a particle size of 10.16 nm and a PDI (polydispersity index) of 0.216. The measurement method was the same as in Example 1.

[0092] (4) The reverse micelle solution obtained in step (3) is placed in a reaction vessel in which the temperature can be accurately controlled. The desiccant reaction waste liquid is added and mixed at a mass ratio of 2:1. The mixture is extracted for 2.0 h at a pH of 9 and a temperature of 50°C. The mixture is separated using a separatory funnel to obtain the upper oil phase.

[0093] (5) Place the upper oil phase from step (3) into a reaction vessel where the temperature can be accurately controlled, add solvent in a mass ratio of 1:4 and mix to obtain a mixture; extract the mixture at pH 8 and temperature 50°C for 2.0 h, separate the liquids using a separatory funnel to obtain the lower aqueous phase;

[0094] (6) Collect the lower aqueous phase from step (5) and place it in a dry place to evaporate slowly.

[0095] The method for determining capsaicin content is the same as in Example 1.

[0096] Example 5: Preparation of reverse micelles and separation of capsaicin

[0097] The method for preparing the reverse micelle solution and the method for separating capsaicin in this embodiment include the following steps:

[0098] (1) Place n-hexane into a container and sonicate it according to the ratio of Span 20 and Span 80, with a total concentration of 50 mm and a concentration ratio of 9:1. Control the ultrasonic power at 60 kHz and obtain solution A in 100 min.

[0099] (2) Under the conditions of shaking and stirring at a speed of 600 rpm and a temperature of 40℃, add dropwise twice the mass of a 1.5 mol / L NaCl solution to the liquid A obtained in step (1) to obtain solution B;

[0100] (3) Centrifuge the solution B obtained in step (2) at 8000 rpm for 20 min and take the supernatant to obtain the reverse micelle solution;

[0101] The resulting nanoemulsion had a particle size of 15.00 nm and a PDI (polydispersity index) of 0.129. The measurement method was the same as in Example 1.

[0102] (4) The reverse micelle solution obtained in step (3) is placed in a reaction vessel in which the temperature can be accurately controlled. The desiccant reaction waste liquid is added and mixed in a mass ratio of 3:1. Extraction is carried out for 2.5 h at pH 10 and temperature 60℃. The mixture is separated by a separatory funnel to obtain the upper oil phase.

[0103] (5) Place the upper oil phase from step (3) into a reaction vessel where the temperature can be accurately controlled, add solvent in a mass ratio of 1:5 and mix to obtain a mixture; extract the mixture at pH 9 and temperature 60°C for 2.5 h, separate the liquids using a separatory funnel to obtain the lower aqueous phase;

[0104] (6) Collect the lower aqueous phase from step (5) and place it in a dry place to evaporate slowly.

[0105] The method for determining capsaicin content is the same as in Example 1.

[0106] Example 6: Determination of capsaicin extraction rate before and after extraction

[0107] The aqueous phase from step (3) was heated at 100°C until the water was almost completely evaporated, and then heating was stopped. After cooling to room temperature, acetonitrile was added and stirred. The solution was filtered through a 0.45 nm cellulose acetate membrane filter. The absorbance was measured in a 1 cm quartz cuvette using a 280 nm UV spectrophotometer to determine the capsaicin content. The pre-extraction rate was then calculated according to the following formula, and the results are as follows: Figures 3-6 As shown.

[0108] .

[0109] The aqueous phase from step (5) was heated at 100°C until the water was almost completely evaporated, and then heating was stopped. After cooling to room temperature, acetonitrile was added and stirred. The solution was filtered through a 0.45 nm cellulose acetate membrane filter. The absorbance was measured in a 1 cm quartz cuvette using a 280 nm UV spectrophotometer to determine the capsaicin content. The post-extraction rate was then calculated according to the following formula, and the results are as follows. Figures 7-9 As shown

[0110] .

[0111] Comparative Example 1

[0112] (1) Place n-hexane into a container, and sonicate it according to Span 20, with a concentration of 10 mm. Control the ultrasonic power at 20 kHz and obtain solution A in 20 min.

[0113] (2) Under the conditions of shaking and stirring at a speed of 300 rpm and a temperature of 20℃, add 0.5 times the mass of a 0.5 mol / L NaCl solution dropwise to the liquid A obtained in step (1) to obtain solution B;

[0114] (3) Centrifuge the solution B obtained in step (2) at 6000 rpm for 10 min and take the supernatant to obtain the solution;

[0115] The above solution cannot extract capsaicin.

[0116] Comparative Example 2

[0117] (1) Place n-hexane into a container, and sonicate it according to Span 80 with a concentration of 10 mm. Control the ultrasonic power at 20 kHz and obtain solution A in 20 min.

[0118] (2) Under the conditions of shaking and stirring at a speed of 300 rpm and a temperature of 20℃, add 0.5 times the mass of a 0.5 mol / L NaCl solution dropwise to the liquid A obtained in step (1) to obtain solution B;

[0119] (3) Centrifuge the solution B obtained in step (2) at 6000 rpm for 10 min and take the supernatant to obtain the solution;

[0120] The above solution cannot extract capsaicin.

[0121] In this application, Span 20 and Span 80 work synergistically; if only one of the substances is used, capsaicin cannot be extracted.

[0122] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing reverse micelles for extracting capsaicin, characterized in that: Includes the following steps: S1: Add Span 20 and Span 80 to n-hexane, and then sonicate to obtain liquid A; S2: Add NaCl solution to liquid A obtained in step S1 under shaking and stirring conditions to obtain solution B. Centrifuge solution B and the supernatant is the reverse micelle solution used to extract capsaicin. In step S1, the concentrations of Span 20 and Span 80 are 10–50 mmol / L; In step S1, the concentration ratio of Span 20 to Span 80 is 1:1 to 7:3; The mass of NaCl solution added in step S2 is 0.5 to 2 times the mass of liquid A; The concentration of the NaCl solution added in step S2 is 0.5 mol / L to 2 mol / L.

2. The method for preparing reverse micelles for extracting capsaicin according to claim 1, characterized in that: The ultrasonic power in step S1 is 20 kHz to 60 kHz, and the ultrasonic time is 20 min to 100 min.

3. The method for preparing reverse micelles for extracting capsaicin according to claim 1, characterized in that: In step S2, the temperature of the agitation is 20℃~40℃, and the rotation speed is 300 rpm~600 rpm; And / or, the centrifugation speed in step S2 is 6000 rpm to 8000 rpm, and the centrifugation time is 10 min to 20 min.

4. The reverse micelles prepared by the method for preparing reverse micelles for extracting capsaicin according to any one of claims 1-3.

5. The method of using the reverse micelles according to claim 4, characterized in that: Includes the following steps: A1: The reverse micelle solution was mixed with the waste liquid from the desiccant reaction and extracted. After separation, the upper oil phase was obtained. A2: Mix the upper oil phase obtained in step A1 with a solvent to obtain a mixture; extract the mixture, separate the liquid and retain the lower aqueous phase, and obtain capsaicin by evaporation and crystallization of the lower aqueous phase.

6. The method of using the reverse micelles according to claim 5, characterized in that: The volume ratio of the desiccant removal reaction waste liquid to the reverse micelle solution in step A1 is 1:3 to 3:1; And / or, the waste liquid from the desiccant reaction and the reverse micelle solution are extracted for 0.5h to 2.5h at a pH of 6 to 11 and a temperature of 20℃ to 60℃.

7. The method of using the reverse micelles according to claim 6, characterized in that: Extraction was carried out in a reaction vessel with precise temperature control, reaching the set temperature of 20℃ to 60℃ within 5 min to 10 min, with a pH value of 6 to 11, and a reaction time of 0.5 h to 2.5 h.

8. The method of using the reverse micelles according to claim 5, characterized in that: In step A2, the mass ratio of the upper oil phase to the solvent is 1:1 to 1:5; And / or, the solvent is either distilled water or tap water.

9. The method of using the reverse micelles according to claim 5, characterized in that: In step A2, the mixture is extracted for 0.5 h to 2.5 h at a pH of 5 to 9 and a temperature of 20 °C to 60 °C. The mixture is then separated using a separatory funnel, and the lower aqueous phase is retained. The extraction reaction was carried out in a reaction vessel with precise temperature control, reaching the set temperature of 20℃ to 60℃ within 5 min to 10 min, with a pH value of 5 to 9, and the reaction time was 0.5 h to 2.5 h.

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