A purification process of l-lysine

Abstract

The application discloses a kind of purification process of L-lysine, comprising the following steps: prepared L-lysine hydrochloride solution is passed through resin column, and is automatically collected, and L-lysine collection solution is obtained, after filtration, concentration, spray drying, vacuum drying, L-lysine finished product is obtained;Wherein, the mode of automatic collection is as follows: when the conductivity value is in ≥100us / cm, effluent is collected, when the conductivity drops to ≤100us / cm, collection is ended.The method overcomes the above-mentioned method and timeliness, equipment requirement is high, and the drawbacks such as labor intensity is big, ensure the timeliness and accuracy of process monitoring, and realize automatic control, and ensure that L-lysine yield and purity are higher.

Description

Technical Field

[0001] This invention belongs to the field of biochemical drug preparation and purification, and relates to amino acid purification technology. Background Technology

[0002] Lysine is a basic building block of proteins and a raw material for the synthesis of human hormones, enzymes, and antibodies. It participates in human metabolism and various physiological activities. Lysine is an essential amino acid and is present in virtually all amino acid infusion formulations. It can also be used as an adjunct to diuretics to treat aluminum poisoning caused by decreased blood chloride levels; it can react with acids (such as salicylic acid) to form salts, thus reducing adverse reactions; when used in combination with methionine, it can inhibit severe hypertension; and lysine is also an excellent thrombotic preventative agent. The demand for L-lysine is also increasing in other applications such as polypeptide synthesis chemistry, biochemical research, and the preparation of lysine derivatives.

[0003] Currently, L-lysine is generally supplied to the market in the form of L-lysine hydrochloride. Free L-lysine is highly hygroscopic, easily turns yellow and deteriorates due to its free amino group, and has a pungent, fishy odor, making it difficult to preserve for long periods. Consequently, relatively little L-lysine is available on the market. L-lysine hydrochloride, on the other hand, is more stable, less prone to deliquescence, and easier to store. However, in clinical applications, such as human injection of lysine hydrochloride, it cannot completely replace the function of lysine. Therefore, obtaining high-purity and stable L-lysine (base) is essential.

[0004] Free L-lysine can be prepared from L-lysine hydrochloride. Currently, the extraction process of L-lysine in China generally adopts the strong cation exchange method, and a small number of studies use the anion exchange method. The detection methods for process control include HPLC-ELSD and acid-base titration. HPLC-ELSD has high equipment requirements and high detection costs. Acid-base titration requires manual operation, which is labor-intensive and requires manual sampling, which is time-consuming and cannot be automated.

[0005] Chinese patent application CN 103787904 A discloses a method for preparing an L-lysine base solution. The method includes: passing a lysine hydrochloride solution onto an anion exchange resin at low temperature, converting the lysine hydrochloride into L-lysine (base), which flows out of the resin column. The collected permeate is the stock solution of L-lysine base. After adjusting the concentration and pH of the stock solution, it is dispensed into ampoules under nitrogen purging to obtain an injectable S-adenosylmethionine solvent. This preparation method only collects the fraction above 750 nm (8823B UV detector, 210 nm) in the 0.2A range. Although the applicant found that this method can maintain a high content and purity of L-lysine base, a significant amount of L-lysine is lost, resulting in a decreased yield. Summary of the Invention

[0006] This invention provides a purification process for L-lysine, which overcomes the drawbacks of the above methods, such as poor timeliness, high equipment requirements, and high labor intensity. It ensures the timeliness and accuracy of process monitoring and realizes automated control. While ensuring the preservation of L-lysine, it also effectively improves the yield.

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

[0008] A purification process for L-lysine includes the following steps:

[0009] The prepared L-lysine hydrochloride solution was passed through a resin column and automatically collected to obtain L-lysine collection liquid. The collection liquid was filtered, concentrated, spray-dried, and vacuum-dried to obtain the L-lysine product.

[0010] The automatic collection methods are as follows:

[0011] When the conductivity value is ≥100 μS / cm, the effluent is collected; when the conductivity drops to ≤100 μS / cm, the collection is stopped.

[0012] The biggest difference between this invention and traditional methods lies in applying conductivity to the L-lysine preparation process. Based on the correspondence between conductivity value and L-lysine content, the electromagnetic valve is switched on and off by the signal fed back from the monitored conductivity value, realizing the start and end of L-lysine collection and achieving automated control. Compared with ultraviolet detection methods, the collection endpoint can be determined more accurately, effectively improving the yield while ensuring purity.

[0013] A certain concentration of lysine hydrochloride exists in a neutral solution as negatively charged chloride ions and positively charged lysine. The chloride ions competitively displace the hydroxide ions on the strongly basic resin, allowing the lysine to pass directly through. The conductivity meter electrode is installed in the lysine solution outflow pipe, and the conductivity meter detects the conductivity value of the lysine. Based on the correspondence between conductivity and lysine content, a setting is made. When the conductivity value is higher than the set value, the solenoid valve opens to collect lysine; when it is lower than the set value, the solenoid valve closes to stop collection, thus achieving the purpose of automatic control.

[0014] In the production and purification process of L-lysine (base), conductivity is used to monitor the L-lysine content online. The electrical signal fed back from the conductivity monitoring controls the opening and closing of valves, thereby automating the start and end of the L-lysine purification process. The conductivity is particularly critical, as it affects the yield and purity of the final L-lysine product.

[0015] Preferably, the resin used in the resin column is a strongly basic anion exchange resin, and more preferably, UBA200 strongly basic anion exchange resin.

[0016] Preferably, the strongly basic anion exchange resin is pretreated to carry -OH groups. The pretreatment method is to pretreat with an alkaline solution.

[0017] Preferably, the mass percentage concentration of the L-lysine hydrochloride solution is 5.0% to 10.0%.

[0018] Preferably, the flow rate of the L-lysine hydrochloride solution through the resin column is 1–2 BV.

[0019] Preferably, the conductivity meter electrode is installed in the lysine solution outflow pipe. The conductivity value of lysine is detected by the conductivity meter. When the conductivity value is higher than the set conductivity value, the solenoid valve opens to collect lysine. When the conductivity value is lower than the set value, the solenoid valve closes to stop collecting.

[0020] Preferably, the concentration temperature of the L-lysine solution is 60-65°C.

[0021] Preferably, the spray drying conditions are an inlet air temperature of 120–125°C, an outlet air temperature of 90–100°C, and a feed rate controlled at 50–60 L / h.

[0022] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0023] The online control of the production process in this invention reduces the labor intensity of sampling and testing, saves testing costs, and eliminates the need for personnel on duty, thus reducing labor costs. The online conductivity detection equipment is commonly used, inexpensive, and readily available. At the same time, this method improves the yield and purity of L-lysine, with a column yield of over 95%, a total yield of 89%, and a product content (HPLC) of over 99%. Detailed Implementation

[0024] According to the present invention, a novel method for preparing L-lysine is shown below, and the present invention is described in more detail by examples, but is not limited thereto.

[0025] Example 1

[0026] (1) Resin treatment: 900L of UBA200 strong basic anion exchange resin was packed into a resin column. First, the column was repeatedly washed with purified water at 30-40℃ until the foam disappeared. Then, 1M NaOH solution was passed through the resin column at a flow rate of 1 column bed volume per hour for a total flow rate of 3 column bed volumes. The column was then rinsed with water until the pH value was below 9.0. Next, 1M sulfuric acid was passed through the column at a flow rate of 1 column bed volume per hour for a total flow rate of 3 column bed volumes. The column was then rinsed with water until the pH value was above 5.0. Finally, 1M NaOH was passed through the column at a flow rate of 1 column bed volume per hour for a total flow rate of 4 column bed volumes. The column was then rinsed with water until the pH value was neutral.

[0027] Sample loading amount: 125 kg of L-lysine hydrochloride (content ≥98.5%) on 900 L of UBA200 strong basic anion exchange resin.

[0028] Preparation of loading solution: Add an appropriate amount of purified water, add 125 kg of L-lysine hydrochloride to make a loading concentration of 7.5%, stir to dissolve and obtain the loading solution.

[0029] Collection: Set the conductivity meter to automatic control mode. Start collection when the conductivity value is ≥100 μS / cm and stop collection when the conductivity value is ≤100 μS / cm. Pass the prepared L-lysine hydrochloride solution through the resin column at a flow rate of 1 BV. When the conductivity value rises rapidly to ≥100 μS / cm, the solenoid valve of the L-lysine solution collection vessel opens to start automatic collection. After sample loading, wash with purified water at a flow rate of 1 BV. The wash solution is also automatically collected into the L-lysine (alkaline) solution collection vessel. When the conductivity drops to ≤100 μS / cm, the solenoid valve of the L-lysine (alkaline) solution collection vessel closes to end collection. Stir well to obtain the L-lysine (alkaline) collected solution. The L-lysine content is determined to be 3.65%, the chromatographic purity is 99.9%, and the column yield is 97.7%.

[0030] (2) The L-lysine collection solution obtained in step (1) is filtered with a 0.22um precision filter. The filtered L-lysine collection solution is concentrated under vacuum at 60-65℃ to a concentration of about 20% L-lysine. The concentration is then stopped to obtain L-lysine concentrate.

[0031] (3) The L-lysine concentrate obtained in step (2) is pumped into a spray dryer by a peristaltic pump. The inlet air temperature is 120℃ and the outlet air temperature is 90~100℃. Spray drying is carried out with the feed rate controlled at 60L / h. After drying, the spray-dried product is taken out from the hopper to obtain L-lysine spray-dried product.

[0032] (4) The L-lysine spray-dried product obtained in step (3) is put into a double cone dryer and mixed for 1 hour. Samples are taken for testing, and the loss on drying should be ≤4.0%. If the loss is unacceptable, the jacket temperature of the double cone dryer is controlled at 60-65℃, and the vacuum degree is ≥0.09Mpa. Samples are taken every 2 hours to measure the loss on drying until it meets the standard. 88 kg of L-lysine (base) product is obtained, with a total L-lysine yield of 88% and a content (HPLC external standard method) of 100.4%, meeting the quality standards. Some product residue remains in the spray drying tower and double cone dryer during the spray drying and double cone drying processes; this residue can be combined with the next batch for further processing.

[0033] Example 2

[0034] (1) Resin treatment: 900L of UBA200 strong basic anion exchange resin was packed into a resin column. First, the column was repeatedly washed with purified water at 30-40℃ until the foam disappeared. Then, 1M NaOH solution was passed through the resin column at a flow rate of 1 column bed volume per hour for a total flow rate of 3 column bed volumes. The column was then rinsed with water until the pH value was below 9.0. Next, 1M sulfuric acid was passed through the column at a flow rate of 1 column bed volume per hour for a total flow rate of 3 column bed volumes. The column was then rinsed with water until the pH value was above 5.0. Finally, 1M NaOH was passed through the column at a flow rate of 1 column bed volume per hour for a total flow rate of 4 column bed volumes. The column was then rinsed with water until the pH value was neutral.

[0035] Sample loading amount: 125 kg of L-lysine hydrochloride (content ≥98.5%) on 900 L of UBA200 strong basic anion exchange resin.

[0036] Preparation of loading solution: Add an appropriate amount of purified water, add 125 kg of L-lysine hydrochloride to make a loading concentration of 7.5%, stir to dissolve and obtain the loading solution.

[0037] Collection: Set the conductivity meter to automatic control mode. Start collection when the conductivity value is ≥150 μS / cm and stop collection when the conductivity value is ≤150 μS / cm. Pass the prepared L-lysine hydrochloride solution through the resin column at a flow rate of 1 BV. When the conductivity value rises rapidly to ≥150 μS / cm, open the solenoid valve of the L-lysine solution collection vessel to start automatic collection. After sample loading, wash with purified water at a flow rate of 1 BV. The wash solution is also automatically collected into the L-lysine (alkaline) solution collection vessel. When the conductivity drops to ≤150 μS / cm, close the solenoid valve of the L-lysine (alkaline) solution collection vessel to end collection. Stir well to obtain L-lysine (alkaline) collected solution. The L-lysine content is determined to be 3.91%, the chromatographic purity is 99.5%, and the column yield is 98.9%.

[0038] (2) The L-lysine collection solution obtained in step (1) is filtered with a 0.22um precision filter. The filtered L-lysine collection solution is concentrated under vacuum at 60-65℃ until the concentration is about 20% L-lysine. The concentration is then stopped to obtain L-lysine concentrate.

[0039] (3) The L-lysine concentrate obtained in step (2) is pumped into a spray dryer by a peristaltic pump. The inlet air temperature is 120℃ and the outlet air temperature is 90~100℃. Spray drying is carried out with the feed rate controlled at 60L / h. After drying, the spray-dried product is taken out from the hopper to obtain L-lysine spray-dried product.

[0040] (4) The L-lysine spray-dried product obtained in step (3) is put into a double cone dryer and mixed for 1 hour. Samples are taken for testing, and the loss on drying should be ≤4.0%. If the loss is unacceptable, the jacket temperature of the double cone dryer is controlled at 60-65℃, and the vacuum degree is ≥0.09Mpa for reduced pressure drying. Samples are taken every 2 hours to measure the loss on drying until it meets the requirements. 89 kg of L-lysine (base) product is obtained, with a total L-lysine yield of 89% and a content (HPLC external standard method) of 99.3%, meeting the quality standards. Some product residue remains in the spray drying tower and double cone dryer during the spray drying and double cone drying processes; this residue can be combined with the next batch for further processing.

Claims

1. A purification process for L-lysine, characterized in that, Includes the following steps: The prepared L-lysine hydrochloride solution was passed through a resin column and automatically collected to obtain L-lysine collection liquid. The collection liquid was filtered, concentrated, spray-dried, and vacuum-dried to obtain the L-lysine product. The automatic collection methods are as follows: When the conductivity value is ≥100 μS / cm, the effluent is collected; when the conductivity drops to ≤100 μS / cm, the collection is stopped. The resin used in the resin column is UBA200 strong basic anion exchange resin. The flow rate of L-lysine hydrochloride solution through the resin column is 1~2 BV; The conductivity meter electrode is installed in the lysine solution outflow pipe. The conductivity value of lysine is detected by the conductivity meter. When the conductivity value is higher than the set value, the solenoid valve opens to collect lysine. When the conductivity value is lower than the set value, the solenoid valve closes and the collection stops.

2. The purification process for L-lysine according to claim 1, characterized in that, The strongly basic anion exchange resin is pretreated to carry -OH radicals.

3. The purification process for L-lysine according to claim 1, characterized in that, The mass percentage concentration of the L-lysine hydrochloride solution is 5.0~10.0%.

4. The purification process for L-lysine according to claim 1, characterized in that, The concentration temperature of the L-lysine solution is 60-65℃.

5. The purification process for L-lysine according to claim 1, characterized in that, The spray drying conditions are: inlet air temperature 120℃~125℃, outlet air temperature 90~100℃, and feed rate controlled at 50~60L / h.