Reverse micelle for extracting capsaicin and preparation method thereof

Abstract

The invention provides a reverse micelle for extracting capsaicin and a preparation method thereof, and the preparation method comprises the following steps: S1, adding Span 20 and Span 80 into normal hexane, and carrying out ultrasonic treatment to obtain a solution A; s2, a NaCl solution is added into the liquid A obtained in the step S1 under the condition of oscillation stirring, a solution B is prepared, the solution B is centrifuged, and supernate is the reverse micelle solution used for extracting capsaicin. The method disclosed by the invention has the beneficial effects that the reverse micelle solution with transparent appearance and stable property can be prepared, and the separation of capsaicin is realized by utilizing reverse micelle extraction.

Description

Technical Field

[0001] The invention belongs to the field of reverse micelles, and in particular relates to a reverse micelle for extracting capsaicin and a preparation method thereof. Background Art

[0002] Capsaicin is the major compound in the capsaicinoid family, followed by dihydrocapsaicin, nordihydrocapsaicin, and homodihydrocapsaicin. It is estimated that capsaicin and dihydrocapsaicin together account for about 90% of the total capsaicinoids in chili peppers, which are widely used worldwide in gastronomy, medicinal applications, and personal defense pepper spray. In addition to its use as an ingredient and nutritional element in novel culinary and pharmaceutical formulations, capsaicin can also be used to measure a patient's cough threshold after ingesting cough suppressants. Recent studies have expanded the scope of capsaicin's applications to include neurobiological research, weight management, local analgesia, and antimicrobial defense.

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

[0004] In view of this, the present invention aims to provide a reverse micelle for extracting capsaicin and a preparation method thereof, so as to solve at least one technical problem in the background technology.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows: A method for preparing reverse micelles for extracting capsaicin comprises the following steps: S1: Span 20 and Span 80 were added to n-hexane, and solution A was obtained after ultrasonic treatment; S2: adding NaCl solution to the liquid A obtained in step S1 under shaking and stirring to obtain solution B, centrifuging solution B, and obtaining a supernatant as a reverse micelle solution for extracting capsaicin.

[0006] Further, in step S1, the concentration of Span 20 and Span 80 is 10-50 mmol / L; And / or, in step S1, the concentration ratio of Span 20 to Span 80 is 1:1 to 7:3.

[0007] Furthermore, the ultrasonic power in step S1 is 20 kHz~60 kHz℃, and the ultrasonic time is 20 min~100 min.

[0008] Further, the mass of the NaCl solution added in step S2 is 0.5 to 2 times the mass of the liquid A; and / or, the concentration of the NaCl solution added in step S2 is 0.5 mol / L to 2 mol / L.

[0009] Furthermore, the temperature of the shaking stirring in step S2 is 20°C to 40°C, and the rotation speed is 300 rpm to 600 rpm; And / or, the centrifugal speed in step S2 is 6000 rpm to 8000 rpm, and the centrifugal time is 10 min to 20 min.

[0010] A method for preparing reverse micelles for extracting capsaicin and obtaining reverse micelles.

[0011] The method for using the above reverse micelle comprises the following steps: A1: The reverse micelle solution is mixed with the waste liquid of the deodorization reaction for extraction, and the upper oil phase is obtained after separation; A2: The upper oil phase obtained in step A1 is mixed with a solvent to obtain a mixed solution; the mixed solution is extracted, and the lower aqueous phase is retained after separation, and the lower aqueous phase is evaporated and crystallized to obtain capsaicin.

[0012] Furthermore, the volume ratio of the deodorization reaction waste liquid to the reverse micelle solution in step A1 is 1:3 to 3:1; And / or, the waste liquid from the deodorization reaction is extracted with the reverse micelle solution at a pH of 6 to 11 and a temperature of 20° C. to 60° C. for 0.5 h to 2.5 h; Preferably, the extraction is carried out in a reaction vessel with accurately controlled temperature, reaching a set temperature of 20°C to 60°C within 5 min to 10 min, a pH value of 6 to 11, and a reaction time of 0.5 h to 2.5 h.

[0013] Furthermore, 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 one of distilled water or tap water.

[0014] Further, the mixed solution in step A2 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 the mixture is separated using a separatory funnel to retain the lower aqueous phase; The extraction reaction is carried out in a reaction vessel with accurate temperature control, reaching the set temperature of 20°C to 60°C within 5 min to 10 min, the pH value is 5 to 9, and the reaction time is 0.5h to 2.5h.

[0015] Reverse micelles are molecular aggregates composed of nonpolar surfactants and water, which are both model systems for biological membranes and microreactors for chemical and biological reactions. The size of reverse micelles can be easily adjusted by stabilizing a polar phase (usually water) in a nonpolar phase. Due to their unique properties in solution, reverse micelles play a vital role in a wide range of research applications.

[0016] Compared with the prior art, the reverse micelle for extracting capsaicin and the preparation method thereof described in the present invention have the following advantages: 1. The method of the present invention can prepare a reverse micelle solution with transparent appearance and stable properties and realize the separation of capsaicin by reverse micelle extraction.

[0017] 2. The present invention can quickly separate capsaicin through reverse micelle extraction, thereby improving extraction efficiency in a short time. In addition, this process is carried out under mild conditions, which can prevent the degradation of heat-sensitive components such as capsaicin and ensure the maintenance of its biological activity.

[0018] 3. The reverse micelle exhibits specific selectivity and improves the purity of capsaicin to meet the demand for high-quality products.

[0019] 4. The organic solvents and surfactants in the reverse micelles can be recovered and reused, reducing environmental pollution and production costs, making this method economically feasible while meeting environmental requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a schematic diagram of full wavelength scanning of the standard solution of the present invention; Figure 2 Schematic diagram of the absorbance of the standard solution of the present invention in a 1 cm quartz cuvette; Figure 3 This is a schematic diagram of the front extraction rate at different pH values ​​of the present invention; Figure 4 It is a schematic diagram of the front extraction rate at different times of the present invention; Figure 5 It is a schematic diagram of the front extraction rate at different temperatures of the present invention; Figure 6 It is a schematic diagram of the front extraction rate of different oil-water ratios of the present invention; Figure 7 This is a schematic diagram of the post-extraction rate at different pH values ​​of the present invention; Figure 8 It is a schematic diagram of the post-extraction rate at different times of the present invention; Fig. 9 It is a schematic diagram of the post-extraction rate at different temperatures of the present invention. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0024] The method for preparing the reverse micelle solution and the method for separating capsaicin provided by the present invention comprise the following steps: (1) Span 20 and Span 80 were added to n-hexane and subjected to ultrasonic treatment to prepare solution A; (2) adding NaCl solution dropwise to the liquid A obtained in step (1) under shaking and stirring to obtain solution B; (3) Centrifuging the solution B obtained in step (2) to obtain the supernatant to obtain a reverse micelle solution; (4) mixing the reverse micelle solution obtained in step (3) with the waste liquid of the deodorization reaction, extracting for 0.5 h to 2.5 h at a pH of 6 to 11 and a temperature of 20° C. to 60° C., separating the liquids with a separatory funnel, and retaining the upper oil phase; (5) mixing the upper oil phase of step (3) with a solvent to obtain a mixed solution; extracting the mixed solution at a pH of 5 to 9 and a temperature of 20° C. to 60° C. for 0.5 h to 2.5 h, separating the mixture with a separatory funnel, and retaining the lower aqueous phase; (6) Collect the lower aqueous phase of step (5) and evaporate and crystallize to obtain capsaicin.

[0025] Example 1: Preparation of reverse micelles and separation of capsaicin. The method for preparing the reverse micelle solution and the method for separating capsaicin in this embodiment comprise the following steps: (1) Place n-hexane in a container and perform ultrasonic treatment with Span 20 and Span 80 at a total concentration of 10 mm and a concentration ratio of 1:1. The ultrasonic power is controlled at 20 kHz for 20 min to obtain solution A. (2) adding dropwise 0.5 times the mass of a 0.5 mol / L NaCl solution to the liquid A obtained in step (1) at a shaking stirring rate of 300 rpm and a temperature of 20° C. to obtain a solution B; (3) Centrifuging the solution B obtained in step (2) at 6000 rpm for 10 min, taking the supernatant to obtain a reverse micelle solution; The particle size of the obtained nanoemulsion is 2.486 nm, and the PDI (polydispersity Index) is 0.135. The measurement method is as follows:

[0026] The average particle size and polydispersity index (PDI) of the samples were measured by a nanoparticle size and Zeta potential instrument (Nano Zetasizer, UK). The samples were drawn into a quartz four-sided light-transmitting cell to avoid the generation of bubbles when adding the samples. The system dispersant was set to water, the instrument balance time was set to 100s, the test angle was 173°, and each sample was measured three times.

[0027] The reverse micelle solution obtained in step (3) is placed in a reaction dish capable of accurately controlling the temperature, and the waste liquid of the deodorization reaction is added in a mass ratio of 1:3 to mix, and extracted for 0.5 h at a pH of 6 and a temperature of 20° C., and separated with a separatory funnel to obtain an upper oil phase; (5) placing the upper oil phase of step (3) into a reaction dish capable of accurately controlling the temperature, adding solvents in a mass ratio of 1:1 to mix, and obtaining a mixed solution; extracting the mixed solution at a pH of 5 and a temperature of 20° C. for 0.5 h, and separating the mixture with a separatory funnel to obtain a lower aqueous phase; (6) Collect the lower aqueous phase from step (5) and place it in a dry place for slow evaporation.

[0028] The specific steps for measuring capsaicin content are as follows: UV analysis of capsaicin: Preparation of standard: 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 solution was scanned at full wavelength using a UV spectrophotometer, and the required wavelength was identified by the corresponding peak. The results are shown in Figure 1 The standard curve was constructed by measuring the absorbance of the standard solution in a 1 cm quartz cuvette. The results are shown in Figure 2 As shown. Calculate the capsaicin content in the unknown extract solution based on the absorbance value of the known standard solution. Use a UV spectrophotometer with a wavelength of 280 nm to measure the absorbance of the filtered solution in a 1 cm quartz cuvette. Calculate the capsaicin content in the unknown extract solution based on the absorbance value of the known standard solution.

[0029] Step (4) lower aqueous phase 270.44 mg / L, upper oil phase 165.76 mg / L step (5) lower aqueous phase 71.27 mg / L, the capsaicin content in the de-spiciness reaction waste liquid is 436.2 mg / L.

[0030] Example 2: Preparation of reverse micelles and separation of capsaicin The method for preparing the reverse micelle solution and the method for separating capsaicin in this embodiment comprise the following steps: (1) placing n-hexane in a container, and subjecting it to ultrasonic treatment according to a ratio of Span 20 and Span 80, with a total concentration of 20 mm and a concentration ratio of 3:2, with the ultrasonic power controlled at 30 kHz, for 40 minutes to obtain a solution A; (2) adding dropwise 1 times the mass of a 0.7 mol / L NaCl solution to the liquid A obtained in step (1) at a shaking stirring rate of 400 rpm and a temperature of 30° C. to obtain a solution B; (3) Centrifuging the solution B obtained in step (2) at 7000 rpm for 15 min, taking the supernatant to obtain a reverse micelle solution; The particle size of the obtained nanoemulsion is 3.153 nm, and the PDI (polydispersity Index) is 0.227. Measurement method The measurement method is the same as that in Example 1.

[0031] (4) placing the reverse micelle solution obtained in step (3) into a reaction dish capable of accurately controlling the temperature, adding the waste liquid of the deodorization reaction in a mass ratio of 1:2, and extracting for 1 h at a pH of 7.57 and a temperature of 27.61° C., and separating the liquids with a separatory funnel to obtain an upper oil phase; (5) placing the upper oil phase of step (3) into a reaction dish capable of accurately controlling the temperature, adding solvents in a mass ratio of 1.307:1 to mix, and obtaining a mixed solution; extracting the mixed solution at a pH of 7 and a temperature of 60° C. for 1.5 h, and separating the mixture with a separatory funnel to obtain a lower aqueous phase; (6) Collect the lower aqueous phase from step (5) and place it in a dry place for slow evaporation.

[0032] The method for determining the capsaicin content is the same as in Example 1.

[0033] 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 de-spiciness reaction waste liquid is 436.2 mg / L.

[0034] Example 3: Preparation of reverse micelles and separation of capsaicin The method for preparing the reverse micelle solution and the method for separating capsaicin in this embodiment comprise the following steps: (1) n-hexane was placed in a container and subjected to ultrasonic treatment according to a ratio of Span 20 and Span 80 with a total concentration of 30 mm and a concentration ratio of 7:3. The ultrasonic power was controlled at 40 kHz for 60 min to obtain solution A. (2) adding dropwise 1.5 times the mass of a 0.9 mol / L NaCl solution to the liquid A obtained in step (1) at a shaking stirring rate of 500 rpm and a temperature of 40° C. to obtain a solution B; (3) Centrifuging the solution B obtained in step (2) at 8000 rpm for 20 min to obtain the supernatant to obtain a reverse micelle solution; The particle size of the obtained nanoemulsion is 8.717 nm, and the PDI (polydispersity Index) is 0.1773. Measurement method The measurement method is the same as that in Example 1.

[0035] (4) placing the reverse micelle solution obtained in step (3) into a reaction dish capable of accurately controlling the temperature, adding the waste liquid of the deodorization reaction in a mass ratio of 1:1, and extracting for 1.5 h at a pH of 8 and a temperature of 40° C., and separating the liquids with a separatory funnel to obtain an upper oil phase; (5) placing the upper oil phase of step (3) into a reaction dish capable of accurately controlling the temperature, adding solvents in a mass ratio of 1:3 to mix, and obtaining a mixed solution; extracting the mixed solution at a pH of 7 and a temperature of 40° C. for 1.5 h, and separating the mixture with a separatory funnel to obtain a lower aqueous phase; (6) Collect the lower aqueous phase from step (5) and place it in a dry place for slow evaporation.

[0036] The method for determining the capsaicin content is the same as in Example 1.

[0037] 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 de-spiciness reaction waste liquid is 436.2 mg / L.

[0038] Example 4: Preparation of reverse micelles and separation of capsaicin The method for preparing the reverse micelle solution and the method for separating capsaicin in this embodiment comprise the following steps: (1) n-hexane was placed in a container and subjected to ultrasonic treatment according to a ratio of Span 20 and Span 80 with a total concentration of 40 mm and a concentration ratio of 4:1. The ultrasonic power was controlled at 50 kHz for 80 min to obtain solution A. (2) adding dropwise 2 times the mass of a 1.1 mol / L NaCl solution to the liquid A obtained in step (1) at a shaking stirring rate of 600 rpm and a temperature of 40° C. to obtain a solution B; (3) Centrifuging the solution B obtained in step (2) at 8000 rpm for 20 min to obtain the supernatant to obtain a reverse micelle solution; The particle size of the obtained nanoemulsion is 10.16 nm, and the PDI (polydispersity Index) is 0.216. Measurement method The measurement method is the same as that in Example 1.

[0039] (4) placing the reverse micelle solution obtained in step (3) into a reaction dish capable of accurately controlling the temperature, adding the waste liquid of the deodorization reaction in a mass ratio of 2:1, and extracting for 2.0 h at a pH of 9 and a temperature of 50° C., and separating the liquids with a separatory funnel to obtain an upper oil phase; (5) placing the upper oil phase of step (3) into a reaction dish capable of accurately controlling the temperature, adding solvents in a mass ratio of 1:4 to mix, and obtaining a mixed solution; extracting the mixed solution at a pH of 8 and a temperature of 50° C. for 2.0 h, and separating the mixture using a separatory funnel to obtain a lower aqueous phase; (6) Collect the lower aqueous phase from step (5) and place it in a dry place for slow evaporation.

[0040] The method for determining the capsaicin content is the same as in Example 1.

[0041] Example 5. Preparation of reverse micelles and separation of capsaicin The method for preparing the reverse micelle solution and the method for separating capsaicin in this embodiment comprise the following steps: (1) n-hexane was placed in a container and subjected to ultrasonic treatment according to a ratio of Span 20 and Span 80 with a total concentration of 50 mM and a concentration ratio of 9:1. The ultrasonic power was controlled at 60 kHz for 100 min to obtain solution A. (2) adding dropwise 2 times the mass of a 1.5 mol / L NaCl solution to the liquid A obtained in step (1) at a shaking stirring rate of 600 rpm and a temperature of 40° C. to obtain a solution B; (3) Centrifuging the solution B obtained in step (2) at 8000 rpm for 20 min to obtain the supernatant to obtain a reverse micelle solution; The particle size of the obtained nanoemulsion was 15.00 nm, and the PDI (polydispersity Index) was 0.129. Measurement Method The measurement method was the same as that in Example 1.

[0042] (4) placing the reverse micelle solution obtained in step (3) into a reaction dish capable of accurately controlling the temperature, adding the waste liquid of the deodorization reaction in a mass ratio of 3:1, and extracting for 2.5 h at a pH of 10 and a temperature of 60° C., and separating the liquids with a separatory funnel to obtain an upper oil phase; (5) placing the upper oil phase of step (3) into a reaction dish capable of accurately controlling the temperature, adding solvents in a mass ratio of 1:5 to mix, and obtaining a mixed solution; extracting the mixed solution at a pH of 9 and a temperature of 60° C. for 2.5 h, and separating the mixture with a separatory funnel to obtain a lower aqueous phase; (6) Collect the lower aqueous phase from step (5) and place it in a dry place for slow evaporation.

[0043] The method for determining the capsaicin content is the same as in Example 1.

[0044] Example 6: Determination of the extraction rate of capsaicin before and after The aqueous phase in step (3) was heated at 100°C until the water was almost completely evaporated, and then the 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 UV spectrophotometer at a wavelength of 280 nm to determine the capsaicin content. The pre-extraction rate was then calculated according to the following formula, and the result was as follows: Figures 3 to 6 shown.

[0045] .

[0046] The aqueous phase in step (5) was heated at 100°C until the water was almost completely evaporated, and then the 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 UV spectrophotometer at a wavelength of 280 nm to determine the capsaicin content. The post-extraction rate was then calculated according to the following formula, and the results were as follows: Figures 7-9 Shown

[0047] .

[0048] Comparative Example 1 (1) Place n-hexane in a container and perform ultrasonic treatment at a Span 20 concentration of 10 mm with the ultrasonic power controlled at 20 kHz for 20 min to obtain solution A; (2) adding dropwise 0.5 times the mass of a 0.5 mol / L NaCl solution to the liquid A obtained in step (1) at a shaking stirring rate of 300 rpm and a temperature of 20° C. to obtain a solution B; (3) Centrifuging the solution B obtained in step (2) at 6000 rpm for 10 min to obtain the supernatant to obtain a solution; The above solutions are unable to extract capsaicin.

[0049] Comparative Example 2 (1) Place n-hexane in a container and perform ultrasonic treatment at a concentration of 10 mm according to Span 80. The ultrasonic power is controlled at 20 kHz for 20 min to obtain solution A. (2) adding dropwise 0.5 times the mass of a 0.5 mol / L NaCl solution to the liquid A obtained in step (1) at a shaking stirring rate of 300 rpm and a temperature of 20° C. to obtain a solution B; (3) Centrifuging the solution B obtained in step (2) at 6000 rpm for 10 min to obtain the supernatant to obtain a solution; The above solutions are unable to extract capsaicin.

[0050] In the present application, Span 20 and Span 80 act synergistically. If only one of the substances is used, capsaicin cannot be extracted.

[0051] 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing reverse micelles for extracting capsaicin, characterized in that: The steps include: S1: Span 20 and Span 80 were added to n-hexane, and solution A was obtained after ultrasonic treatment; S2: adding NaCl solution to the liquid A obtained in step S1 under shaking and stirring to obtain solution B, centrifuging solution B, and obtaining a supernatant as a reverse micelle solution for extracting capsaicin.

2. A method for preparing reverse micelles for extracting capsaicin according to claim 1, characterized in that: In step S1, the concentration of Span 20 and Span 80 is 10-50 mmol / L; And / or, in step S1, the concentration ratio of Span 20 to Span 80 is 1:1 to 7:

3.

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

4. A method for preparing reverse micelles for extracting capsaicin according to claim 1, characterized in that: 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.

5. A method for preparing reverse micelles for extracting capsaicin according to claim 1, characterized in that: The temperature of the shaking stirring in step S2 is 20°C to 40°C, and the rotation speed is 300 rpm to 600 rpm; And / or, the centrifugal speed in step S2 is 6000 rpm to 8000 rpm, and the centrifugal time is 10 min to 20 min.

6. The reverse micelle prepared by the method for preparing reverse micelle for extracting capsaicin as described in any one of claims 1 to 5.

7. The method for using the reverse micelle according to claim 6, characterized in that: The steps include: A1: The reverse micelle solution is mixed with the waste liquid of the deodorization reaction for extraction, and the upper oil phase is obtained after separation; A2: The upper oil phase obtained in step A1 is mixed with a solvent to obtain a mixed solution; the mixed solution is extracted, and the lower aqueous phase is retained after separation, and the lower aqueous phase is evaporated and crystallized to obtain capsaicin.

8. The method for using the reverse micelle according to claim 7, characterized in that: The volume ratio of the deodorization reaction waste liquid to the reverse micelle solution in step A1 is 1:3 to 3:1; And / or, the waste liquid from the deodorization reaction is extracted with the reverse micelle solution at a pH of 6 to 11 and a temperature of 20° C. to 60° C. for 0.5 h to 2.5 h; Preferably, the extraction is carried out in a reaction vessel with accurately controlled temperature, reaching a set temperature of 20°C to 60°C within 5 min to 10 min, a pH value of 6 to 11, and a reaction time of 0.5 h to 2.5 h.

9. The method for using the reverse micelle according to claim 7, wherein: Step A2: the mass ratio of the upper oil phase to the solvent is 1:1 to 1:5; And / or, the solvent is one of distilled water or tap water.

10. The method for using the reverse micelle according to claim 7, characterized in that: The mixed solution in step A2 is extracted at a pH of 5 to 9 and a temperature of 20° C. to 60° C. for 0.5 to 2.5 hours, and the mixture is separated using a separatory funnel, and the lower aqueous phase is retained; The extraction reaction is carried out in a reaction vessel with accurate temperature control, reaching the set temperature of 20°C to 60°C within 5 min to 10 min, the pH value is 5 to 9, and the reaction time is 0.5h to 2.5h.

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