Method for separating caulis sinomenii alkaloid by microfiltration-ultrafiltration-nanofiltration-electrodialysis integrated membrane technology

Abstract

The invention belongs to the technical field of traditional Chinese medicine separation and purification, and discloses a method for separating caulis sinomenii alkaloid by a microfiltration-ultrafiltration-nanofiltration-electrodialysis integrated membrane technology. An ultrafiltration membrane electrodialysis device is adopted, the ultrafiltration membrane electrodialysis device comprises an anode plate, a cathode plate and a membrane stack arranged between the anode plate and the cathode plate, and the membrane stack is formed by connecting n groups of electrodialysis units in series, the device sequentially comprises an anode, an anode chamber, [a cation exchange membrane, an acid chamber, an anion exchange membrane, a feeding chamber, an ultrafiltration membrane and a product chamber] n, a cation exchange membrane, a cathode chamber and a cathode from the anode to the cathode. According to the method, the maximum recovery rate of sinomenine hydrochloride can reach 84.1%, the recovery rate of magnoflorine can reach 68.2%, the method is a simple and efficient multi-membrane integrated separation method with low energy consumption and small pollution, and a new thought is provided for separation and purification in the field of traditional Chinese medicine alkaloids.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of traditional Chinese medicine separation and purification, and particularly relates to a method for separating alkaloids in Caulis Sinomenii by integrated membrane technology of microfiltration-ultrafiltration-nanofiltration-electrodialysis. BACKGROUND

[0002] Caulis Sinomenii is the dried stem of Caulis Sinomenii and Sinomenium acutum of the family Menispermaceae, mainly produced in Henan, Shaanxi, Jiangxi and other provinces and cities, and has pharmacological effects of anti-inflammatory, analgesic, immunosuppressive, anti-tumor, anti-angiocardiopathy and the like. Alkaloids are one of main functional components of Caulis Sinomenii, including more than 50 kinds of alkaloids such as sinomenine, bis-sinomenine, magnoflorine, cepharanthine, tetrahydropalmatine, berberine and corydine. Among them, sinomenine accounts for 80% of the total alkaloid content of Caulis Sinomenii, and is often used in the form of hydrochloride in clinical practice. Song Bencao Tujing proposed that it can treat “wind”, and has been called a magic drug for “wind” disease ever since, such as a representative drug “Zhengqing Fengtongning”, which has a hydrochloride content of 90%.

[0003] At present, the methods for preparing alkaloids in Caulis Sinomenii mainly include ethanol reflux method, alkalization reflux method and acid water extraction method, among which the acid water extraction method is most widely used. Subsequent separation and purification is carried out through steps such as calcium salt precipitation, chloroform extraction and acidification to obtain alkaloids in Caulis Sinomenii. However, the above-mentioned traditional methods have the disadvantages of large consumption of organic reagents, low efficiency, complicated steps and the like in the extraction or separation and purification process, and the treatment of waste residues and waste liquid is easy to cause environmental pollution, and the cost is high, which needs to be further researched to realize green production.

[0004] Membrane separation technology separates mixed solutions by means of the characteristics of membranes, and is a biological membrane separation with high selectivity. With the continuous development of pharmaceutical processes, pressure-driven membranes such as microfiltration, ultrafiltration and nanofiltration have been widely used in different unit operations of traditional Chinese medicine water extract, and have become a feasible alternative to many traditional methods of traditional Chinese medicine processing with the advantages of high efficiency, low energy consumption, environmental safety and the like. In the process of electrically driven membrane separation, charged particles migrate directionally under the driving of a direct current electric field and selectively permeate the membrane to realize selective removal, concentration and conversion of ions in the solution, and efficiently separate different charged components in the solution. However, the recovery rate and efficiency of membrane separation technology in treating alkaloids in Caulis Sinomenii are low.

[0005] Therefore, how to provide a method for separating alkaloids in Caulis Sinomenii by integrated membrane technology of microfiltration-ultrafiltration-nanofiltration-electrodialysis is a technical problem to be solved by those skilled in the art. SUMMARY

[0006] In view of the above, the present application provides a method for separating sinomenine alkaloids by microfiltration-ultrafiltration-nanofiltration-electrodialysis integrated membrane technology.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: The method for separating sinomenine alkaloids by microfiltration-ultrafiltration-nanofiltration-electrodialysis integrated membrane technology adopts an ultrafiltration membrane electrodialysis device, wherein the ultrafiltration membrane electrodialysis device comprises an anode plate, a cathode plate, and a membrane stack arranged between the anode plate and the cathode plate, the membrane stack is composed of n groups of electrodialysis units connected in series, and the device sequentially comprises, from the anode to the cathode, an anode-anode chamber-[cation exchange membrane-acid chamber-anion exchange membrane- feed chamber-ultrafiltration membrane-product chamber]n-cation exchange membrane-cathode chamber-cathode. The method for separating sinomenine alkaloids comprises the following steps: S1, taking sinomenine powder, adding hydrochloric acid aqueous solution, and extracting to obtain a crude extract in an ultrasonic wave, and filtering with gauze to obtain a water extract; S2, sending the water extract into a microfiltration ceramic membrane for microfiltration treatment to obtain a permeate 1; S3, sending the permeate 1 into an ultrafiltration membrane A for ultrafiltration treatment to remove macromolecular impurities, and obtaining a permeate 2; S4, sending the permeate 2 into an ultrafiltration membrane B for ultrafiltration treatment to retain small molecular effective components, and obtaining a permeate 3; S5, sending the permeate 3 into a nanofiltration membrane for nanofiltration treatment to obtain a concentrated solution; S6, adding the concentrated solution into the ultrafiltration membrane electrodialysis device for separation and purification, and obtaining sinomenine alkaloids in the product chamber.

[0008] Preferably, the value of n is 1-1000.

[0009] Preferably, in the step S2, the pore size of the microfiltration ceramic membrane is 20-200 nm, and the microfiltration pressure is 0.1-0.5 MPa.

[0010] Preferably, in the step S3, the pore size of the ultrafiltration membrane A is 5-20 kDa, and the ultrafiltration pressure is 0.2-0.8 MPa.

[0011] Preferably, in the step S4, the pore size of the ultrafiltration membrane B is 1-5 kDa, and the ultrafiltration pressure is 0.2-0.8 MPa.

[0012] Preferably, in the step S5, the pore size of the nanofiltration membrane is 150-300 Da, and the nanofiltration pressure is 0.8-1.2 MPa.

[0013] Preferably, in the step S5, the concentration multiple of the nanofiltration is 2-8.

[0014] Preferably, the specific operation of the step S6 is as follows: different concentrations of hydrochloric acid aqueous solution are added into the acid chamber and the product chamber respectively, sulfuric acid solution is added into the anode chamber and the cathode chamber respectively, the concentrated solution obtained in the step S5 is added into the feed chamber, and power is applied to operate.

[0015] Preferably, in the step S6, when the conductivity of the feed chamber and the product chamber decreases to 5 mS / cm, 2 mol / L hydrochloric acid is added dropwise into the feed chamber and the product chamber.

[0016] Preferably, in the step S6, the concentration of the hydrochloric acid aqueous solution in the acid chamber is 0.02-0.1 mol / L, and the concentration of the hydrochloric acid aqueous solution in the product chamber is 0.05-0.2 mol / L.

[0017] Preferably, in the step S6, the concentration of the sulfuric acid solution is 0.1-0.6 mol / L.

[0018] Preferably, in the step S6, the pore size of the ultrafiltration membrane is 1-10 kDa.

[0019] Preferably, in the step S6, the linear velocity of the solution in each chamber is 3 cm / s.

[0020] Preferably, in the step S6, the ultrafiltration membrane electrodialysis device is operated in a constant voltage mode, and the voltage is 20-50 V.

[0021] Preferably, the ultrafiltration membrane electrodialysis device further comprises a liquid storage tank corresponding to each of the anode chamber, the cathode chamber, the acid chamber, the feed chamber and the product chamber, and a circulating pump; the anode chamber, the cathode chamber, the acid chamber, the feed chamber and the product chamber are each provided with a feed inlet and a discharge outlet, each chamber is communicated with the corresponding liquid storage tank through a pipeline, and a self-circulation loop is formed by the respective circulating pumps.

[0022] Compared with the prior art, the application has the following beneficial effects: The application adopts microfiltration-ultrafiltration-nanofiltration-electrodialysis membrane integrated technology to directly perform membrane separation on the water extract of traditional Chinese medicine, and the process is simple. The microfiltration membrane can remove particles, colloids and the like in the water extract of traditional Chinese medicine, the 10 kDa ultrafiltration membrane can remove large molecular organic matters such as proteins and polysaccharides in the water extract of traditional Chinese medicine, the 1 kDa ultrafiltration membrane can effectively retain small molecular organic matters such as alkaloids and flavones in the water extract of traditional Chinese medicine, and the nanofiltration can effectively concentrate the target alkaloids. Meanwhile, the application avoids using too much organic solvent in the separation process. Secondly, the ultrafiltration membrane is added to the traditional electrodialysis device to realize effective transmission and screening of the charged alkaloids of traditional Chinese medicine by using the advantage of large pore size. The hydrochloric acid recovered from the nanofiltration permeate and the acid chamber can be reused for the extraction of the water extract after dilution, thereby solving the problem of difficult treatment of part of waste liquid. The separation and purification method provided by the application is an economical, simple, efficient and environment-friendly production method, and provides a new idea for green production of traditional Chinese medicine. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced, and the drawings in the description are only some embodiments of the present application.

[0024] Figure 1 The application is a circulating process flow chart for separating alkaloids of Sinomenium acutum.

[0025] Figure 2 The application is a structure schematic diagram of an ultrafiltration membrane electrodialysis device. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0027] In the embodiments, the microfiltration ceramic membrane used in the pressure-driven membrane process is an Al2O3 tubular ceramic membrane (membrane area: 0.12 m 2 , model: 1812) produced by Jiangsu Jiugu High-tech Co., Ltd. 2 The ultrafiltration membrane is a PES roll-type ultrafiltration membrane (membrane area: 0.3 m 2, model: 1812). The ion exchange membrane used in the ultrafiltration membrane electrodialysis device is CGU cation exchange membrane and AGU anion exchange membrane produced by Japan ASTOM Company, and the ultrafiltration membrane is PES flat ultrafiltration membrane produced by Beijing Kailaiyang Membrane Technology Co., Ltd.

[0028] Take the powder of Sinomenium acutum, add 0.1 M hydrochloric acid aqueous solution according to the solid-liquid ratio of 1:70, and extract the crude extract under the condition of ultrasonic temperature of 50℃ for 30 min. Filter with gauze to obtain the water extract. The concentration of sinomenine hydrochloride in the obtained water extract is 0.19 g / L, and the concentration of magnoflorine is 0.07 g / L.

[0029] Example 1 The pressure-driven membrane device adopts a microfiltration-ultrafiltration-nanofiltration integrated membrane process for treatment. The treatment method is as follows: the water extract is microfiltered under 0.2 MPa through a 20 nm microfiltration ceramic membrane, and the permeate 1 is taken; the permeate 1 is ultrafiltered under 0.2 MPa through a 10 kDa roll-type ultrafiltration membrane, and the permeate 2 is taken; the permeate 2 is ultrafiltered under 0.8 MPa through a 1 kDa roll-type ultrafiltration membrane, and the permeate 3 is taken; finally, the permeate 3 is nanofiltered and concentrated 3 times under 1.0 MPa through a 200-300 Da roll-type nanofiltration membrane, and the retentate, i.e. the concentrated liquid, is taken; the permeate 4 obtained by nanofiltration is recycled with hydrochloric acid and returned to the ultrasonic extraction as the reagent raw material.

[0030] The electrically driven membrane process adopts Figure 2 The ultrafiltration membrane electrodialysis device shown in the figure, the ultrafiltration membrane electrodialysis device includes an anode plate, a cathode plate and a membrane stack placed between the anode plate and the cathode plate, the membrane stack is composed of n groups of electrodialysis units connected in series, the device is sequentially arranged from the anode to the cathode as follows: anode-anode chamber-[cation exchange membrane-acid chamber-anion exchange membrane- feed chamber-ultrafiltration membrane-product chamber]n-cation exchange membrane-cathode chamber, the number of repeated units n is 3, and the effective area of all single membranes is 20 cm 2 , wherein the anode and the cathode are both made of titanium coated with ruthenium. The anode chamber, the cathode chamber, the acid chamber, the feed chamber and the product chamber are all provided with a feed inlet and a discharge outlet, each chamber is connected with its corresponding liquid storage tank through a pipeline, and a self-circulation loop is formed by the respective circulating pumps.

[0031] An anode chamber and a cathode chamber were formed between the anode plate and the cathode plate and the adjacent membranes, and the two chambers were connected in series. 200 mL of 0.3 mol / L sulfuric acid was introduced as an electrode solution, 200 mL of 0.02 mol / L hydrochloric acid solution was introduced into the acid chamber, 200 mL of 3-fold concentrated solution after treatment by the integrated membrane process was introduced into the feed chamber, and 200 mL of 0.05 mol / L hydrochloric acid solution was introduced into the product chamber. During the experiment, the linear velocity of the solution in each compartment was 3 cm / s, the experiment was operated in a constant voltage mode, the voltage was set to 30 V, and the molecular weight cut-off of the ultrafiltration membrane was 1000 Da.

[0032] During the experiment, the device was operated for 60 min. Finally, the yield of sinomenine hydrochloride in the product chamber was 14.5%, the yield of magnoflorine was 13.7%, and the energy consumption was 0.58 kWh / g.

[0033] Example 2 The pressure-driven membrane device and the ultrafiltration membrane electrodialysis device used in this example were the same as those in Example 1.

[0034] An anode chamber and a cathode chamber were formed between the anode plate and the cathode plate and the adjacent membranes, and the two chambers were connected in series. 200 mL of 0.3 mol / L sulfuric acid was introduced as an electrode solution, 200 mL of 0.02 mol / L hydrochloric acid solution was introduced into the acid chamber, 200 mL of 3-fold concentrated solution after treatment by the integrated membrane process was introduced into the feed chamber, and 200 mL of 0.05 mol / L hydrochloric acid solution was introduced into the product chamber. During the experiment, the linear velocity of the solution in each compartment was 3 cm / s, the experiment was operated in a constant voltage mode, the voltage was set to 30 V, and the molecular weight cut-off of the ultrafiltration membrane was 3500 Da.

[0035] During the experiment, the device was operated for 60 min. Finally, the yield of sinomenine hydrochloride in the product chamber was 22.5%, the yield of magnoflorine was 19.5%, and the energy consumption was 0.36 kWh / g.

[0036] Example 3 The pressure-driven membrane device and the ultrafiltration membrane electrodialysis device used in this example were the same as those in Example 1.

[0037] An anode chamber and a cathode chamber were formed between the anode plate and the cathode plate and the adjacent membranes, and the two chambers were connected in series. 200 mL of 0.3 mol / L sulfuric acid was introduced as an electrode solution, 200 mL of 0.02 mol / L hydrochloric acid solution was introduced into the acid chamber, 200 mL of 3-fold concentrated solution after treatment by the integrated membrane process was introduced into the feed chamber, and 200 mL of 0.05 mol / L hydrochloric acid solution was introduced into the product chamber. During the experiment, the linear velocity of the solution in each compartment was 3 cm / s, the experiment was operated in a constant voltage mode, the voltage was set to 30 V, and the molecular weight cut-off of the ultrafiltration membrane was 5000 Da.

[0038] During the experiment, the device ran for 60 min. Finally, the yield of sinomenine hydrochloride in the product chamber was 23.6%, the yield of magnoflorine was 22.6%, and the energy consumption was 0.33 kWh / g.

[0039] Example 4 The pressure-driven membrane device and the ultrafiltration membrane electrodialysis device used in this example were the same as those in Example 1.

[0040] An anode chamber and a cathode chamber were formed between the anode plate and the cathode plate and the adjacent membranes, and the two chambers were connected in series. 200 mL of 0.3 mol / L sulfuric acid was introduced as an electrode solution, 200 mL of 0.02 mol / L hydrochloric acid solution was introduced into the acid chamber, 200 mL of 3-fold concentrated solution after treatment by the integrated membrane process was introduced into the feed chamber, and 200 mL of 0.05 mol / L hydrochloric acid solution was introduced into the product chamber. During the experiment, the linear velocity of the solution in each compartment was 3 cm / s, the experiment was operated in a constant voltage mode, the voltage was set to 20 V, and the molecular weight cut-off of the ultrafiltration membrane was 5000 Da.

[0041] During the experiment, the device ran for 60 min. Finally, the yield of sinomenine hydrochloride in the product chamber was 23.6%, the yield of magnoflorine was 22.6%, and the energy consumption was 0.33 kWh / g.

[0042] Example 5 The pressure-driven membrane device and the ultrafiltration membrane electrodialysis device used in this example were the same as those in Example 1.

[0043] An anode chamber and a cathode chamber were formed between the anode plate and the cathode plate and the adjacent membranes, and the two chambers were connected in series. 200 mL of 0.3 mol / L sulfuric acid was introduced as an electrode solution, 200 mL of 0.02 mol / L hydrochloric acid solution was introduced into the acid chamber, 200 mL of 3-fold concentrated solution after treatment by the integrated membrane process was introduced into the feed chamber, and 200 mL of 0.05 mol / L hydrochloric acid solution was introduced into the product chamber. During the experiment, the linear velocity of the solution in each compartment was 3 cm / s, the experiment was operated in a constant voltage mode, the voltage was set to 40 V, and the molecular weight cut-off of the ultrafiltration membrane was 5000 Da.

[0044] During the experiment, due to the high voltage, the ion migration was too fast, the current density was low in the later stage, and the experiment could not be maintained. The device ran for 57.5 min. Finally, the yield of sinomenine hydrochloride in the product chamber was 23.2%, the yield of magnoflorine was 21.7%, and the energy consumption was 0.41 kWh / g.

[0045] Example 6 The pressure-driven membrane device and the ultrafiltration membrane electrodialysis device used in this example are the same as those in Example 1.

[0046] The anode plate and the cathode plate form an anode chamber and a cathode chamber with the adjacent membranes, and the two chambers are connected in series. 200 mL of 0.3 mol / L sulfuric acid is introduced as an electrode solution, 200 mL of 0.02 mol / L hydrochloric acid solution is introduced into the acid chamber, 200 mL of 6-fold concentrated solution after the integrated membrane process is introduced into the feed chamber, and 200 mL of 0.05 mol / L hydrochloric acid solution is introduced into the product chamber. During the experiment, the linear velocity of the solution in each compartment is 3 cm / s, the experiment adopts a constant voltage operation mode, the voltage is set to 30 V, and the molecular weight cut-off of the ultrafiltration membrane is 5000 Da.

[0047] During the experiment, due to the high voltage, the ion migration is too fast, the current density is low in the later stage, and the experiment cannot be maintained. The running time of the device is 50 min. Finally, the yield of sinomenine hydrochloride in the product chamber is 21.1 %, the yield of magnoflorine is 20.4 %, and the energy consumption is 0.46 kWh / g.

[0048] Example 7 The pressure-driven membrane device adopts the microfiltration-ultrafiltration-nanofiltration integrated membrane process for treatment. The treatment method is as follows: the water extract is microfiltered under 0.2 MPa through a 20 nm microfiltration ceramic membrane, and the permeate 1 is taken; the permeate 1 is ultrafiltered under 0.2 MPa through a 10 kDa roll-type ultrafiltration membrane, and the permeate 2 is taken; the permeate 2 is ultrafiltered under 0.8 MPa through a 1 kDa roll-type ultrafiltration membrane, and the permeate 3 is taken; finally, the permeate 3 is nanofiltered and concentrated 6 times under 1.0 MPa through a 200-300 Da roll-type nanofiltration membrane, and the retentate, i.e. the concentrated solution, is taken.

[0049] The ultrafiltration membrane electrodialysis device used in this example is the same as that in Example 1.

[0050] The anode plate and the cathode plate form an anode chamber and a cathode chamber with the adjacent membranes, and the two chambers are connected in series. 200 mL of 0.3 mol / L sulfuric acid is introduced as an electrode solution, 200 mL of 0.02 mol / L hydrochloric acid solution is introduced into the acid chamber, 200 mL of 6-fold concentrated solution after the integrated membrane process is introduced into the feed chamber, and 200 mL of 0.05 mol / L hydrochloric acid solution is introduced into the product chamber. During the experiment, the linear velocity of the solution in each compartment is 3 cm / s, the experiment adopts a constant voltage operation mode, the voltage is set to 30 V, and the molecular weight cut-off of the ultrafiltration membrane is 5000 Da.

[0051] During the experiment, the ion migration was too fast due to the high concentration gradient, and the current density was low in the later stage, which could not maintain the experiment running. The device running time was 52.5 min. Finally, the yield of sinomenine hydrochloride in the product chamber was 12.9%, the yield of magnoflorine was 10.9%, and the energy consumption was 0.28 kWh / g.

[0052] Example 8 The pressure-driven membrane device and the ultrafiltration membrane electrodialysis device used in this example were the same as those in Example 7.

[0053] The anode chamber and the cathode chamber were formed between the anode plate and the cathode plate and the adjacent membrane, and the two chambers were connected in series. 200 mL of 0.3 mol / L sulfuric acid was used as the electrode solution, 200 mL of 0.02 mol / L hydrochloric acid solution was used in the acid chamber, 200 mL of 6-fold concentrated solution after integrated membrane process was used in the feed chamber, and 200 mL of 0.05 mol / L hydrochloric acid solution was used in the product chamber. During the experiment, the linear velocity of the solution in each compartment was 3 cm / s, the experiment was operated in a constant voltage mode, the voltage was set to 30 V, and the molecular weight cut-off of the ultrafiltration membrane was 5000 Da.

[0054] During the experiment, the inorganic ion migration was too fast, which led to a low current density in the later stage, and the EDUF could not maintain the separation of alkaloids. Therefore, when the conductivity of the feed chamber and the product chamber decreased to 5 mS / cm, 4 mL of 2 mol / L hydrochloric acid was added to the feed chamber and the product chamber, respectively, and the device running time ended after 330 min. Finally, the yield of sinomenine hydrochloride in the product chamber was 84.1%, the yield of magnoflorine was 68.2%, and the energy consumption was 0.47 kWh / g.

[0055] The experimental conditions, product recovery rate and energy consumption described in Examples 1-8 are shown in Table 1: Table 1 Experimental conditions and results of Examples 1-8

[0056] As can be seen from the above examples, the method has obvious effect on the separation and purification of sinomenine alkaloids. As can be seen from Examples 1-3, the increase of the pore size of the ultrafiltration membrane in the ultrafiltration membrane electrodialysis is conducive to the separation of sinomenine alkaloids; under the same pore size, low voltage leads to low current density, and thus low recovery rate of alkaloids, while high voltage leads to too fast migration of inorganic ions, and the alkaloids cannot be effectively migrated; meanwhile, under the same pore size and the same voltage, high feed concentration leads to high concentration gradient, which promotes the migration of inorganic ions and alkaloids. Therefore, as shown in Example 8, under the conditions of 5000 Da, 40 V, 6 times of nanofiltration concentration, and continuous operation for 330 min, the maximum recovery rate of sinomenine hydrochloride in sinomenine can reach 84.1%, and the recovery rate of magnoflorine can reach 68.2%.

[0057] The above examples are only used to illustrate the technical solutions of the present application, but not limit the same; although the present application has been described in detail with reference to the foregoing examples, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for separating alkaloids from *Sinomenium acutum* using an integrated membrane technology combining microfiltration, ultrafiltration, nanofiltration, and electrodialysis, characterized in that... An ultrafiltration membrane electrodialysis device is used, which includes an anode plate, a cathode plate, and a membrane stack placed between the anode plate and the cathode plate. The membrane stack is composed of n sets of electrodialysis units connected in series. The device is arranged from anode to cathode as follows: anode-anode chamber-[cation exchange membrane-acid chamber-anion exchange membrane-feed chamber-ultrafiltration membrane-product chamber]n-cation exchange membrane-cathode chamber-cathode; The method for separating alkaloids from *Sinomenium acutum* includes the following steps: S1. Take the powder of *Sinomenium acutum*, add hydrochloric acid aqueous solution, extract it with ultrasound to obtain crude extract, filter it with gauze to obtain aqueous extract. S2. The aqueous extract is fed into a microfiltration ceramic membrane for microfiltration treatment to obtain permeate 1. S3. Permeate 1 is fed into ultrafiltration membrane A for ultrafiltration treatment to remove macromolecular impurities and obtain permeate 2. S4. Permeate 2 is fed into ultrafiltration membrane B for ultrafiltration treatment to retain small molecule effective components and obtain permeate 3. S5. Permeate 3 is fed into a nanofiltration membrane for nanofiltration treatment to obtain concentrated solution; S6. The concentrate is added to an ultrafiltration membrane electrodialysis device for separation and purification, and the alkaloids of *Sinomenium acutum* are obtained in the product chamber.

2. The method according to claim 1, characterized in that, The value of n ranges from 1 to 1000.

3. The method according to claim 1, characterized in that, The specific operation of step S6 is as follows: add hydrochloric acid aqueous solutions of different concentrations to the acid chamber and the product chamber respectively, add sulfuric acid solution to the anode chamber and the cathode chamber respectively, add the concentrated solution obtained in step S5 to the feed chamber, and then turn on the power to run.

4. The method according to claim 3, characterized in that, In step S6, when the conductivity of the feed chamber and the product chamber drops to 5 mS / cm, 2 mol / L hydrochloric acid is added dropwise to the feed chamber and the product chamber.

5. The method according to claim 3, characterized in that, In step S6, the concentration of hydrochloric acid aqueous solution in the acid chamber is 0.02~0.1 mol / L, and the concentration of hydrochloric acid aqueous solution in the product chamber is 0.05~0.2 mol / L.

6. The method according to claim 3, characterized in that, In step S6, the concentration of the sulfuric acid solution is 0.1~0.6 mol / L.

7. The method according to claim 3, characterized in that, In step S6, the pore size of the ultrafiltration membrane is 1~10 kDa.

8. The method according to claim 3, characterized in that, In step S6, the linear velocity of the solution flow in each chamber is 3 cm / s.

9. The method according to claim 3, characterized in that, In step S6, the ultrafiltration membrane electrodialysis device operates in constant voltage mode with a voltage of 20~50 V.

10. The method according to claim 1, characterized in that, The ultrafiltration membrane electrodialysis device also includes storage tanks and circulation pumps corresponding to the anode chamber, cathode chamber, acid chamber, feed chamber, and product chamber, respectively. The anode chamber, cathode chamber, acid chamber, feed chamber, and product chamber are each provided with a feed inlet and a discharge outlet. Each chamber is connected to the corresponding storage tank through a pipeline and forms a self-circulating loop powered by its respective circulation pump.

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