Three-pool electrodialysis device and method for recovering eutectic solvent

Abstract

The invention discloses a three-pool electrodialysis device and method for recovering a deep eutectic solvent. The method comprises the following steps: putting a deep eutectic extracting solution sample to be recovered into a sample pool; starting a direct-current power supply, electrifying the anode and the cathode, and performing electrodialysis on the eutectic extracting solution sample; detecting the concentration of a hydrogen bond acceptor in an anion receiving tank in real time, and detecting the concentration of a hydrogen bond donor in a cation receiving tank in real time until the concentration of the hydrogen bond acceptor and the concentration of the hydrogen bond donor are not changed any more, obtaining a hydrogen bond acceptor recovery solution in the anion receiving tank, hydrogen bond donor recovery liquid is obtained in the cation receiving pool; respectively distilling the hydrogen bond acceptor recovery liquid and the hydrogen bond donor recovery liquid, and removing moisture to obtain a recovered hydrogen bond acceptor and a recovered hydrogen bond acceptor; and mixing the recovered hydrogen bond acceptor and the recovered hydrogen bond acceptor according to the ratio of the initial eutectic solvent to obtain the recovered eutectic solvent.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrodialysis separation and recovery, and particularly relates to a three-chamber electrodialysis device and method for recovering deep eutectic solvents. Background Art

[0002] At present, organic solvents such as methanol, ethanol, and chloroform are mostly used as extraction solvents for the extraction of components of traditional Chinese medicine (or plants). However, organic solvents have disadvantages such as flammability, volatility, toxicity, high solvent consumption, and easy residue, and long-term use will cause serious harm to the human body and the environment.

[0003] Deep eutectic solvents (DES) are a new type of green solvent. No additional organic reagents need to be added during the synthesis of DES, and the sources of hydrogen bond donors and hydrogen bond acceptors are abundant. Because of its advantages such as low toxicity, good biodegradability, environmental protection, and simple preparation, it has quickly become a popular research object in the chemical field and shown great application potential in the fields of green chemistry and materials science. Using green solvents to replace traditional organic solvents can effectively reduce environmental pollution and potential harm to human health.

[0004] The green, efficient, and non-toxic advantages of deep eutectic solvents have made them more and more widely used in the extraction of active ingredients of plants. However, there are also disadvantages such as difficult separation of solvents from extracted components and difficult recycling and reuse of solvents. Currently, the methods for separating and recovering deep eutectic solvents are mostly macroporous resin adsorption methods. However, the macroporous resin adsorption method has disadvantages such as complex pretreatment and regeneration of resins, limited adsorption selectivity, and the need to elute the required compounds using organic solvents, which does not meet the requirements of green chemistry. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the prior art and provide a three-chamber electrodialysis method for recovering deep eutectic solvents, which can achieve the recovery of deep eutectic solvents, has a high recovery rate, and meets the requirements of green chemistry.

[0006] The present invention also provides a three-chamber electrodialysis device for recovering deep eutectic solvents, which has a simple structure and can reduce the recovery cost.

[0007] The technical solution provided by the present invention is as follows:

[0008] A three-chamber electrodialysis device for recovering deep eutectic solvents, comprising:

[0009] A DC power supply;

[0010] An anion receiving chamber;

[0011] An anode, which is placed in the anion receiving chamber and is connected to the positive electrode of the DC power supply;

[0012] Cation receiving cell;

[0013] A cathode, which is placed in the cation receiving cell and connected to the negative electrode of the DC power supply;

[0014] A sample cell, which is arranged between the anion receiving cell and the cation receiving cell, and both ends of the sample cell are communicated with the anion receiving cell and the cation receiving cell respectively;

[0015] An anion exchange membrane, which is arranged at the communication place between the anion receiving cell and the sample cell;

[0016] A cation exchange membrane, which is arranged at the communication place between the cation receiving cell and the sample cell.

[0017] A three-chamber electrodialysis method for recovering deep eutectic solvents, using the three-chamber electrodialysis device for recovering deep eutectic solvents, includes the following steps:

[0018] Step 1: Put the deep eutectic extraction liquid sample to be recovered into the sample cell;

[0019] Wherein, the deep eutectic extraction liquid sample is a mixed extraction liquid containing extraction components and deep eutectic solvents obtained by extracting traditional Chinese medicine or plant components using deep eutectic solvents;

[0020] Step 2: Turn on the DC power supply to energize the anode and the cathode, and perform electrodialysis on the deep eutectic extraction liquid sample;

[0021] Real-time detect the concentration of hydrogen bond acceptors in the anion receiving cell, and real-time detect the concentration of hydrogen bond donors in the cation receiving cell. Until the concentrations of the hydrogen bond acceptors and the hydrogen bond donors no longer change, a hydrogen bond acceptor recovery liquid is obtained in the anion receiving cell, and a hydrogen bond donor recovery liquid is obtained in the cation receiving cell;

[0022] Step 3: Distill the hydrogen bond acceptor recovery liquid and the hydrogen bond donor recovery liquid respectively to remove water, and obtain the recovered hydrogen bond acceptors and the recovered hydrogen bond donors;

[0023] Step 4: Mix and prepare the recovered hydrogen bond acceptors and the recovered hydrogen bond donors according to the ratio of the initial deep eutectic solvents to obtain the recovered deep eutectic solvents.

[0024] Preferably, in the step 1, it further includes:

[0025] Dilute the deep eutectic extraction liquid sample, and use the diluted deep eutectic extraction liquid sample as the deep eutectic extraction liquid sample to be recovered.

[0026] Preferably, the method for diluting the eutectic extraction liquid sample is as follows:

[0027] Add deionized water to the eutectic extraction liquid sample, and the dilution factor is 1.5 to 3 times.

[0028] Preferably, the preparation method of the eutectic solvent is as follows:

[0029] Mix choline chloride and malic acid at a molar ratio of 1:1, and then add deionized water; heat and stir at 70 °C for 1 h to 2 h to obtain the eutectic solvent;

[0030] Among them, the mass of the added deionized water is 35% of the mass of the eutectic solvent.

[0031] Preferably, when electro-dialysis is performed on the eutectic extraction liquid sample, the voltage is a constant voltage, and the value range of the voltage is 20 V to 40 V.

[0032] Preferably, the anode uses a ruthenium-iridium electrode, and the cathode uses a titanium electrode.

[0033] The beneficial effects of the present invention are as follows:

[0034] The three-chamber electro-dialysis method for recovering the eutectic solvent provided by the present invention has a higher recovery rate compared with the traditional method, does not produce by-products, and has a higher energy utilization rate.

[0035] The three-chamber electro-dialysis device for recovering the eutectic solvent provided by the present invention has a simple structure, saves space, is convenient for installation, and can reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of the three-chamber electro-dialysis device for recovering the eutectic solvent described in the present invention. DETAILED DESCRIPTION

[0037] The following further describes the present invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0038] As Figure 1 shown, the present invention provides a three-chamber electro-dialysis device for recovering a eutectic solvent, including: a DC power supply 110, an anion receiving chamber 120, an anode 130, a cation receiving chamber 140, a cathode 150, a sample chamber 160, an anion exchange membrane 170, and a cation exchange membrane 180.

[0039] The anode 130 is placed in the anion receiving chamber 120 and is connected to the positive pole of the DC power supply 110 through a wire. The cathode 150 is placed in the cation receiving chamber 140 and is connected to the negative pole of the DC power supply 110 through a wire.

[0040] The sample cell 160 is disposed between the anion receiving cell 120 and the cation receiving cell 140, and both ends of the sample cell 160 are respectively communicated with the anion receiving cell 120 and the cation receiving cell 140. An anion exchange membrane 170 is disposed at the communicating part between the anion receiving cell 120 and the sample cell 160. A cation exchange membrane 180 is disposed at the communicating part between the cation receiving cell 140 and the sample cell 160. The anion receiving cell 120 recovers the hydrogen bond acceptor part in the deep eutectic solvent, and the cation receiving cell 140 recovers the hydrogen bond donor part in the deep eutectic solvent.

[0041] The present invention also provides a three-cell electrodialysis method for recovering a deep eutectic solvent, and uses the three-cell electrodialysis device for recovering a deep eutectic solvent provided by the present invention to recover the deep eutectic solvent. The specific implementation process is as follows.

[0042] 1. Put the deep eutectic extraction liquid sample to be recovered into the sample cell.

[0043] Wherein, the deep eutectic extraction liquid sample is a mixed extraction liquid containing the extraction component and the deep eutectic solvent obtained by extracting traditional Chinese medicine or plant components using the deep eutectic solvent.

[0044] As a preference, in one embodiment, before being put into the sample cell, it further includes diluting the mixed extraction liquid containing the extraction component and the deep eutectic solvent obtained after extracting traditional Chinese medicine or plant components. Then, the diluted deep eutectic extraction liquid sample is used as the deep eutectic extraction liquid sample to be recovered and put into the sample cell.

[0045] As a preference, the method for diluting the deep eutectic extraction liquid sample is: adding deionized water to the deep eutectic extraction liquid sample, and the dilution multiple is 1.5 to 3 times.

[0046] By diluting the used deep eutectic extraction liquid sample, it can avoid the pollution of the anion exchange membrane and the cation exchange membrane caused by the deep eutectic extraction with too high a concentration, and affect the anion exchange membrane and the cation exchange membrane. By reasonably setting the dilution multiple, the recovery efficiency and the recovery rate can be improved.

[0047] 2. Turn on the DC power supply to energize the anode and the cathode, and perform electrodialysis on the deep eutectic extraction liquid sample.

[0048] Wherein, when performing electrodialysis on the deep eutectic extraction liquid sample, the voltage is a constant voltage, and the value range of the voltage is 20V to 40V.

[0049] During the process of electrodialysis, the concentration of the hydrogen bond acceptor in the anion receiving pool is detected in real time, and the concentration of the hydrogen bond donor in the cation receiving pool is detected in real time. When the concentrations of both the hydrogen bond acceptor and the hydrogen bond donor no longer change, it is determined that the electrodialysis process is completed, and the DC power supply is turned off. At this time, the hydrogen bond acceptor recovery liquid is obtained in the anion receiving pool, and the hydrogen bond donor recovery liquid is obtained in the cation receiving pool.

[0050] III. The hydrogen bond acceptor recovery liquid and the hydrogen bond donor recovery liquid are respectively distilled to evaporate the water, and then subjected to nitrogen blowing to obtain the recovered hydrogen bond acceptor and the recovered hydrogen bond acceptor.

[0051] IV. The recovered hydrogen bond acceptor and the recovered hydrogen bond acceptor are mixed and prepared according to the initial eutectic solvent ratio and method to obtain the recovered eutectic solvent.

[0052] In one embodiment, the preparation method of the eutectic solvent is as follows: choline chloride and malic acid are mixed at a molar ratio of 1:1, and deionized water is added; heated and stirred at 70 °C for 1 h to 2 h to obtain the eutectic solvent. Among them, the mass of the added deionized water is 35% of the mass of the eutectic solvent.

[0053] In this embodiment, the anode uses a ruthenium-iridium electrode, and the cathode uses a titanium electrode.

[0054] Choline hydroxide (hydrogen bond donor) is recovered in the cation receiving pool, and malic acid (hydrogen bond acceptor) is recovered in the anion receiving pool. After adding hydrochloric acid to the recovered choline hydroxide, water and hydrochloric acid are removed by a rotary evaporator, and after nitrogen blowing, the recovered choline chloride (solid) is obtained; the anion receiving pool distills the recovered malic acid to remove water, and after nitrogen blowing, the recovered malic acid (solid) is obtained. The recovered choline chloride and the recovered malic acid are mixed at a molar ratio of 1:1, deionized water is added, and heated and stirred at 70 °C for 1 h to 2 h to obtain the recovered eutectic solvent. Among them, the mass of the added deionized water is 35% of the mass of the recovered eutectic solvent.

[0055] The following further describes the three-chamber electrodialysis method for recovering eutectic solvents provided by the invention in combination with specific embodiments.

[0056] Example 1

[0057] (1) Take traditional Chinese medicine Paeonia lactiflora Pall., dry it in a constant temperature oven at 70 °C until it reaches a constant weight, crush the dried traditional Chinese medicine Paeonia lactiflora Pall. into powder with a high-speed pulverizer, and sieve it through an 80-mesh sieve for low-temperature storage for later use.

[0058] (2) Mix choline chloride and malic acid at a molar ratio of 1:1, and add deionized water (the mass of deionized water added is 35% of the mass of the eutectic solvent), then heat and stir at 70 °C for 1 h - 2 h until a stable and transparent eutectic solvent is formed. Add the powder of Paeonia lactiflora Pall. to the eutectic solvent at room temperature, and the ratio of the powder of Paeonia lactiflora Pall. to the eutectic solvent is fixed at 1:15 (g·mL -1 ). Then, under the condition of a temperature of 45 °C, continuously extract by ultrasonic for 70 min and then perform suction filtration to remove impurities, obtaining a mixed extract containing the extracted component (total flavonoids) and the eutectic solvent. Use the sodium nitrite (NaNO2)-aluminum nitrate (Al(NO3)3) colorimetric method and substitute it into the rutin standard curve to determine that the total flavonoid extraction rate is 4.52 mg·g -1 .

[0059] (3) Dilute the mixed extract obtained in (2) 1.5 times with deionized water, put it into a sample cell, and perform electrodialysis under the condition of 25 V. Recover choline hydroxide at the cathode (cation receiving cell) and malic acid at the anode (anion receiving cell). Add hydrochloric acid to the recovered choline hydroxide, use a rotary evaporator to remove water and hydrochloric acid, and after nitrogen blowing, obtain the recovered choline chloride; distill off the water from the malic acid recovered in the anion receiving cell to obtain the recovered malic acid. After detection, in this example, the recovery rate of choline chloride is 89%, and the recovery rate of malic acid is 70%.

[0060] (4) Re-mix the recovered choline chloride solution and the recovered malic acid according to the initial molar ratio of 1:1 to prepare a DES, and extract the powder of Paeonia lactiflora Pall. prepared in (1). The measured extraction amount of the total flavonoid extraction rate is 4.06 mg·g -1 .

[0061] Example 2

[0062] (1) Take traditional Chinese medicine Scutellaria baicalensis Georgi, dry it in a constant temperature oven at 70 °C until constant weight, crush the dried traditional Chinese medicine Scutellaria baicalensis Georgi into powder with a high-speed crusher, and pass through an 80-mesh sieve and store it at low temperature for later use.

[0063] (2) Mix choline chloride and malic acid at a molar ratio of 1:1, and add deionized water (the mass of deionized water added is 35% of the mass of the eutectic solvent), then heat and stir at 70 °C for 1 h - 2 h until a stable and transparent eutectic solvent is formed. Add the powder of traditional Chinese medicine Scutellaria baicalensis Georgi to the eutectic solvent at room temperature, and the solid-liquid ratio of the sample is fixed at 1:15 (g·mL -1 ). Then, under the condition of a temperature of 45 °C, continuously extract by ultrasonic for 70 min and then perform suction filtration to remove impurities, obtaining a mixed extract containing the extracted component (total flavonoids) and the eutectic solvent. Use the sodium nitrite (NaNO2)-aluminum nitrate (Al(NO3)3) colorimetric method and substitute it into the rutin standard curve to determine that the total flavonoid extraction rate is 4.77 mg·g-1 。

[0064] (3) Dilute the extract 2-fold with deionized water, place it in a sample cell, and perform electrodialysis under the condition of 20 V. Recover choline hydroxide at the cathode (cationic), and recover malic acid at the anode (anionic receiving cell). Add hydrochloric acid to the recovered choline hydroxide, remove water and hydrochloric acid using a rotary evaporator, and after nitrogen blowing, obtain the recovered choline chloride; distill off the water from the malic acid recovered in the anionic receiving cell, and after nitrogen blowing, obtain the recovered malic acid. Finally, it is measured that the recovery rate of choline chloride is 67%, and the recovery rate of malic acid is 58%.

[0065] (4) Re-mix the recovered choline chloride and the recovered malic acid according to the initial molar ratio of 1:1 to prepare DES and extract the Scutellaria baicalensis stem powder prepared in (1). The total flavonoid extraction rate is measured to be 4.25 mg·g -1 。

[0066] Example 3

[0067] (1) Take the whole plant of Commelina communis, dry it in a constant temperature oven at 70 °C until constant weight, crush the dried whole plant of Commelina communis into powder with a high-speed crusher, and sieve it through an 80-mesh sieve for low-temperature storage for later use.

[0068] (2) Mix choline chloride and malic acid in a molar ratio of 1:1, and add deionized water (the mass of deionized water added is 35% of the mass of the eutectic solvent), then heat and stir at 70 °C for 1 h - 2 h until a stable and transparent eutectic solvent is formed. Add the Commelina communis whole plant powder to the eutectic solvent at room temperature, and the solid-liquid ratio of the sample is fixed at 1:15 (g·mL -1 ), then under the condition of a temperature of 45 °C, continuously extract by ultrasound for 70 min and then filter to remove impurities to obtain a mixed extract of the extraction component (total flavonoids) and the eutectic solvent. The total flavonoid extraction rate is measured to be 4.12 mg·g by the sodium nitrite (NaNO2)-aluminum nitrate (Al(NO3)3) colorimetric method substituting into the rutin standard curve -1 。

[0069] (3) Dilute the mixed extract obtained in (2) 2-fold with deionized water, place it in a sample cell, and perform electrodialysis under the condition of 25 V. Recover choline hydroxide at the cathode (cationic receiving cell), and recover malic acid at the anode (anionic receiving cell). Add hydrochloric acid to the recovered choline hydroxide, remove water and hydrochloric acid using a rotary evaporator, and after nitrogen blowing, obtain the recovered choline chloride; distill off the water from the malic acid recovered in the anionic receiving cell, and after nitrogen blowing, obtain the recovered malic acid. Finally, it is measured that the recovery rate of choline chloride is 67%, and the recovery rate of malic acid is 70%.

[0070] (4) Re - mix the recycled choline chloride and recycled malic acid according to the initial molar ratio of 1:1 to prepare DES, and extract the whole - plant powder of Commelina communis prepared in (1). The total flavonoid extraction rate is measured to be 3.02 mg·g -1 .

[0071] Example 4

[0072] (1) Take Cirsium japonicum, dry it in a constant - temperature oven at 70 °C until constant weight, crush the dried Cirsium japonicum into powder with a high - speed crusher, and pass it through an 80 - mesh sieve for low - temperature storage for later use.

[0073] (2) Mix choline chloride and malic acid in a molar ratio of 1:1, and add deionized water (the mass of deionized water added is 35% of the mass of the eutectic solvent), then heat and stir at 70 °C for 1 h - 2 h until a stable and transparent eutectic solvent is formed. Add the Cirsium japonicum powder to the eutectic solvent at room temperature, and fix the sample solid - liquid ratio at 1:15 (g·mL -1 ), then under the condition of a temperature of 45 °C, continuously extract by ultrasonic wave for 70 min and then filter to remove impurities to obtain a mixed extract containing the extracted components (total flavonoids) and the eutectic solvent. Use the sodium nitrite (NaNO2) - aluminum nitrate (Al(NO3)3) colorimetric method and substitute it into the rutin standard curve to measure the total flavonoid extraction rate as 4.56 mg·g -1 .

[0074] (3) Dilute the mixed extract obtained in (2) 1.5 times with deionized water, put it into a sample cell, and perform electrodialysis under the condition of 20 V. Recover choline hydroxide at the cathode (cation receiving cell) and malic acid at the anode (anion receiving cell). Add hydrochloric acid to the recovered choline hydroxide, use a rotary evaporator to remove water and hydrochloric acid, and after nitrogen blowing, obtain the recycled choline chloride; distill the water from the malic acid recovered in the anion receiving cell and after nitrogen blowing, obtain the recycled malic acid. Finally, it is measured that the recovery rate of choline chloride is 56% and the recovery rate of malic acid is 46%.

[0075] (4) Re - mix the recycled choline chloride solution and recycled malic acid according to the initial molar ratio of 1:1 to prepare DES, and extract the Cirsium japonicum powder prepared in (1). The total flavonoid extraction rate is measured to be 3.18 mg·g -1 .

[0076] Example 5

[0077] (1) Take the stems of Paeonia lactiflora, dry them in a constant - temperature oven at 70 °C until constant weight, crush the dried stems of Paeonia lactiflora into powder with a high - speed crusher, and pass it through an 80 - mesh sieve for low - temperature storage for later use.

[0078] (2) Mix choline chloride and malic acid in a molar ratio of 1:1, and add deionized water (the mass of the added deionized water is 35% of the mass of the eutectic solvent), then heat and stir at 70 °C for 1 h to 2 h until a stable and transparent eutectic solvent is formed. Add the peony stem powder to the eutectic solvent at room temperature, and fix the solid-liquid ratio of the sample at 1:15 (g·mL -1 ), and then, under the condition of a temperature of 45 °C, continuously extract by ultrasonic wave for 70 min and then filter to remove impurities to obtain a mixed extract containing the extraction components (total flavonoids) and the eutectic solvent. The nitrite (NaNO2)-aluminum nitrate (Al(NO3)3) colorimetric method is used and substituted into the rutin standard curve to determine that the total flavonoid extraction rate is 4.89 mg·g -1 .

[0079] (3) Dilute the mixed extract obtained in (2) 3 times with deionized water, and perform electrodialysis under the condition of 20 V. Recover choline hydroxide at the cathode (cation receiving cell) and malic acid at the anode (anion receiving cell). Add hydrochloric acid to the recovered choline hydroxide, use a rotary evaporator to remove water and hydrochloric acid, and after nitrogen blowing, obtain the recovered choline chloride; distill the malic acid recovered in the anion receiving cell to remove water, and after nitrogen blowing, obtain the recovered malic acid. Finally, it is measured that the recovery rate of choline chloride is 65% and the recovery rate of malic acid is 52%.

[0080] (4) Re-mix the recovered choline chloride solution and the recovered malic acid according to the initial molar ratio of 1:1 to prepare a DES, and extract the peony stem powder prepared in (1), and measure that the total flavonoid extraction rate is 3.21 mg·g -1 .

[0081] In each of the above examples, the recovery rate of choline chloride (malic acid) refers to the percentage of the mass of the recovered choline chloride (malic acid) after electrodialysis in the mass of malic acid in the mixed extract.

[0082] The determination methods used in each of the above examples and comparative examples are described as follows:[[]]END]]

[0083] The total flavonoid content is determined by the nitrite-aluminum nitrate method:

[0084] The calculation formula for the total flavonoid extraction rate is:

[0085] Total flavonoid extraction rate (mg·g -1 ) = C·D·V / M

[0086] In the formula: C is the total flavonoid concentration of the test solution, mg·mL -1 ; D is the solution dilution factor; V is the volume of the DES solvent, mL; M is the total mass of the peony stems used for extraction, g.

[0087] The content of malic acid was determined by ultraviolet spectrophotometry:

[0088] The calculation formula for the recovery rate of malic acid is:

[0089]

[0090] In the formula, C is the concentration of malic acid, μg / m; D is the dilution factor during the determination by ultraviolet spectrophotometry; V is the total volume of the malic acid solution, mL; m: the mass of the remaining malic acid after DES extraction.

[0091] The content of choline chloride was determined with reference to the national standard GB / T 6432-2018:

[0092] The calculation formula for the recovery rate of choline chloride is:

[0093]

[0094] In the formula, V2: the amount of HCL consumed during titration, mL; V1: the amount of HCL consumed in the blank experiment, mL; C: the concentration of HCL, mol / L; the molecular weight of nitrogen atom, g / mol; F: the average coefficient for converting nitrogen to choline chloride; m': the mass of the sample taken for the determination of the sample, g / mL; V3: the volume of the digestion solution for distillation, mL; V: the total volume of the sample digestion solution, mL; V': the total volume of the recovered choline chloride solution, mL; M': the mass of the remaining choline chloride after DES extraction, g.

[0095] The present invention utilizes the principle of electrodialysis. The electrolyte components such as choline chloride and malic acid in the mixed extraction solution containing the extraction components (total flavonoids) and the deep eutectic solvent migrate through the anion and cation exchange membranes under the action of an electric field, while other neutral extraction components (such as flavonoid compounds, etc.) in the mixed extraction solution will remain in the sample pool due to their non-electrolyte properties, so that the deep eutectic solvent can be recovered while separating the extraction components of traditional Chinese medicine (plants).

[0096] It can be seen from Examples 1-5 that through the three-chamber electrodialysis method for recovering the deep eutectic solvent provided by the present invention, the recovery rate is relatively high; in addition, the reconstituted deep eutectic solvent after recovery can still be reused and maintains good reuse performance. 70% ethanol was used to extract the total flavonoids from the traditional Chinese medicine powder in Examples 1-5 as a control experiment, and the average extraction rate of the total flavonoids was 2.12 mg·g -1 , it can be seen that the reconstituted deep eutectic solvent after recovery has a significantly higher extraction effect on the total flavonoids than 70% ethanol on the extraction of the total flavonoids. This further proves that the reconstituted deep eutectic solvent after recovery still has good reuse performance.

[0097] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those skilled in the art, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated examples described herein.

Claims

1. A three-cell electrodialysis device for recycling deep eutectic solvents, characterized in that, Comprising: A DC power supply; An anion receiving cell; An anode, which is placed in the anion receiving cell and connected to the positive pole of the DC power supply; A cation receiving cell; A cathode, which is placed in the cation receiving cell and connected to the negative pole of the DC power supply; A sample cell, which is arranged between the anion receiving cell and the cation receiving cell, and both ends of the sample cell are communicated with the anion receiving cell and the cation receiving cell respectively; An anion exchange membrane, which is arranged at the communication place between the anion receiving cell and the sample cell; A cation exchange membrane, which is arranged at the communication place between the cation receiving cell and the sample cell.

2. A three-cell electrodialysis method for recovering deep eutectic solvents, characterized in that, Using the three-chamber electrodialysis device for recovering deep eutectic solvents as described in claim 1, comprising the following steps: Step 1, putting the deep eutectic extraction liquid sample to be recovered into the sample cell; Wherein, the deep eutectic extraction liquid sample is: a mixed extraction liquid containing the extraction components and the deep eutectic solvent obtained after using the deep eutectic solvent to extract traditional Chinese medicine or plant components; Step 2, turning on the DC power supply to energize the anode and the cathode, and performing electrodialysis on the deep eutectic extraction liquid sample; Real-time detecting the concentration of the hydrogen bond acceptor in the anion receiving cell and real-time detecting the concentration of the hydrogen bond donor in the cation receiving cell. Until the concentrations of the hydrogen bond acceptor and the hydrogen bond donor no longer change, a hydrogen bond acceptor recovery liquid is obtained in the anion receiving cell, and a hydrogen bond donor recovery liquid is obtained in the cation receiving cell; Step 3, respectively distilling the hydrogen bond acceptor recovery liquid and the hydrogen bond donor recovery liquid to remove moisture, obtaining the recovered hydrogen bond acceptor and the recovered hydrogen bond acceptor; Step 4, mixing and preparing the recovered hydrogen bond acceptor and the recovered hydrogen bond acceptor according to the ratio of the initial deep eutectic solvent to obtain the recovered deep eutectic solvent.

3. The three-cell electrodialysis method for recycling deep eutectic solvents according to claim 2, characterized in that, In the said Step 1, it further includes: Diluting the deep eutectic extraction liquid sample, and using the diluted deep eutectic extraction liquid sample as the deep eutectic extraction liquid sample to be recovered.

4. The three-chamber electrodialysis method for recycling deep eutectic solvents according to claim 3, characterized in that, The method for diluting the deep eutectic extraction liquid sample is: Adding deionized water to the deep eutectic extraction liquid sample, and the dilution multiple is 1.5 to 3 times.

5. The three-chamber electrodialysis method for recovering deep eutectic solvents according to any one of claims 2-4, characterized in that The preparation method of the deep eutectic solvent is: Mixing choline chloride and malic acid in a molar ratio of 1:1, and then adding deionized water; heating and stirring at 70 °C for 1 h to 2 h to obtain the deep eutectic solvent; Wherein, the mass of the added deionized water is 35% of the mass of the deep eutectic solvent.

6. The three-chamber electrodialysis method for recycling deep eutectic solvents according to claim 5, characterized in that, When performing electrodialysis on the deep eutectic extraction liquid sample, the voltage is a constant voltage, and the value range of the voltage is 20 V to 40 V.

7. The three-chamber electrodialysis method for recycling eutectic solvents according to claim 6, characterized in that, The anode adopts a ruthenium-iridium electrode, and the cathode adopts a titanium electrode.

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