Preparation method of vitamin B12 for removing cyanide residues

Abstract

The invention provides a preparation method of vitamin B12 for removing cyanide residues, and relates to the technical field of preparation of vitamin B12. The preparation method comprises the following steps: (1) adding sodium thiosulfate and potassium ferrocyanide into a to-be-converted solution, flocculating and filtering to obtain a filtrate I; (2) adding a cyanide treating agent composed of polyaluminum chloride and diatomite into the filtrate I, filtering, and concentrating the filtrate to obtain a concentrated solution; and (3) adsorbing the concentrated solution through macroporous resin, and resolving the concentrated solution through an acetone aqueous solution to obtain the vitamin B12. According to the preparation method provided by the invention, sodium thiosulfate and potassium ferrocyanide are jointly used, so that the conversion rate of the vitamin B12 is increased, meanwhile, the content of cyanide in the vitamin B12 is effectively reduced through treatment of a combined cyanide treatment agent consisting of polyaluminum chloride and diatomite, and the effects of safety and environmental protection are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of vitamin B12, and in particular relates to a method for preparing vitamin B12 by removing cyanide residues. Background Art

[0002] Vitamin B12, referred to as VB12, also known as cyanocobalamin, is an important vitamin and a necessary coenzyme in the synthesis of ribonucleic acid and deoxyribonucleic acid. It is mainly found in animal foods, such as liver, kidney, pig heart, lean meat, fish, milk and egg yolk. In industrial production, denitrifying Pseudomonas is generally used for aerobic fermentation to produce adenosylcobalamin fermentation broth, and then vitamin B12 is obtained through extraction, transformation and purification. Among them, the process of removing the deoxyadenosylcobalamin group from the cobalt atom in the adenosylcobalamin molecule and combining it with the -CN group to become cyanocobalamin is called conversion. In general production processes, conversion is achieved by adding potassium cyanide or sodium cyanide, but since sodium cyanide and potassium cyanide are highly toxic drugs, they have high safety risks and high management costs, and waste gas, waste water, waste solids and other pollutants will be generated during the conversion. In this regard, Chinese invention patent application CN101736061A discloses a method for producing vitamin B12 by using ferrocyanide complex to achieve conversion, but it requires the addition of a defoamer, which pollutes the feed liquid and is not easy to remove, and there is also a problem of low conversion rate. For this reason, Chinese invention patent application CN116284191A discloses a method for preparing vitamin B12, in which the liquid to be converted is converted into vitamin B12 using sodium nitrite and potassium ferrocyanide, which solves the problem of low conversion rate of vitamin B12 in the prior art, but the patent does not pay attention to the content of cyanide in the product, and the safety and environmental protection need to be further improved.

[0003] Therefore, there is an urgent need to develop a method for preparing vitamin B12 that is safe, environmentally friendly, has a low cyanide content and a high vitamin B12 conversion rate. Summary of the invention

[0004] The present invention aims at the problems existing in the prior art and provides a preparation method of vitamin B12 with cyanide residue removed. The conversion rate of vitamin B12 is improved by the combined use of sodium thiosulfate and potassium ferrocyanide, and the combined cyanide treatment agent composed of polyaluminium chloride and diatomaceous earth is used to effectively reduce the cyanide content in the product, thereby achieving the effects of safety and environmental protection.

[0005] The first aspect of the present invention relates to a method for preparing vitamin B12 by removing cyanide residues, the method comprising the following steps: (1) adding sodium thiosulfate and potassium ferroxanthracene to the liquid to be converted, flocculating and filtering to obtain filtrate I; (2) adding a cyanide treatment agent composed of polyaluminium chloride and diatomaceous earth to the filtrate I, filtering, and concentrating the filtrate to obtain a concentrated solution; (3) adsorbing the concentrated solution with a macroporous resin and analyzing it with an acetone aqueous solution to obtain vitamin B12.

[0006] Preferably, in step (1), the mass volume ratio of potassium ferroxanthate to the liquid to be converted is 1.5-2.5 mg:1 mL.

[0007] Preferably, in step (1), the mass ratio of sodium thiosulfate to potassium ferroxanthate is 1:2-3.

[0008] Preferably, in step (1), before adding sodium thiosulfate, the pH of the liquid to be converted is adjusted to 3-4 using 5% by mass hydrochloric acid.

[0009] Preferably, the liquid to be converted in step (1) is a fermentation liquid primary extract concentrate, which is obtained by destroying the bacterial cell structure of the fermentation liquid, dissolving it in water, filtering, adsorbing, eluting, and concentrating it.

[0010] Preferably, in step (1), a flocculant is added during flocculation, and a filter aid is added during filtration.

[0011] More preferably, the mass volume ratio of the flocculant to the liquid to be converted is 0.1-0.3 mg:1 mL.

[0012] Further preferably, the mass volume ratio of the filter aid to the liquid to be converted is 0.05-0.2 mg:1 mL.

[0013] Preferably, the flocculant is polyaluminium chloride, and the filter aid is diatomaceous earth.

[0014] Preferably, the composition of the cyanide treating agent in step (2) is: 35-40 parts of diatomaceous earth and 5-15 parts of polyaluminium chloride.

[0015] Preferably, in step (2), the mass volume ratio of the cyanide treatment agent to the filtrate I is 3-8 mg:100 mL.

[0016] Preferably, the volume concentration of the acetone aqueous solution in step (3) is 50-70%.

[0017] The working principle and beneficial effects of the present invention are as follows: (1) The present invention provides a method for preparing vitamin B12, wherein the conversion rate of vitamin B12 is improved by using sodium thiosulfate and potassium ferroxanthate in combination with the liquid to be converted, and the yield is above 90%; (2) A combined cyanide treatment agent composed of polyaluminium chloride and diatomaceous earth is used in the preparation process, which effectively reduces the cyanide content in the product and achieves a safe and environmentally friendly effect. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The conversion liquids in the following examples and comparative examples were prepared by the following method: the fermentation liquid was heated to 100°C, the bacterial cell structure was destroyed at pH = 3.5, and then dissolved in water, filtered, and the filtrate was collected. The obtained filtrate was adsorbed and eluted using an adsorption resin, and the liquid was collected, and the obtained liquid was concentrated to obtain the conversion liquid.

[0020] Embodiment 1: A method for preparing vitamin B12 with cyanide residue removed, the method comprising the following steps: (1) After adjusting the pH value of 100 mL of the solution to be converted to 4.0 with 5% hydrochloric acid, 50 mg of sodium thiosulfate and 150 mg of potassium ferrocyanide were added. After the reaction, 10 mg of polyaluminium chloride was added for flocculation, and 5 mg of diatomaceous earth was added for filtration to obtain filtrate I. (2) Add cyanide treatment agent (35 parts of diatomaceous earth and 15 parts of polyaluminium chloride) to filtrate I, the mass volume ratio of cyanide treatment agent to filtrate I is 5 mg:100 mL, filter, concentrate the filtrate to obtain a concentrated solution; (3) The concentrated solution is loaded onto a macroporous resin and eluted first with water and then with a 50% by volume acetone aqueous solution. The acetone aqueous solution elution portion is collected to obtain vitamin B12.

[0021] The eluate from step (3) was measured by high performance liquid chromatography, where the content of vitamin B12 was 4569.4 μg / mL and the content of cyanide was 11.4 μg / L.

[0022] Embodiment 2: A method for preparing vitamin B12 with cyanide residue removed, the method comprising the following steps: (1) After adjusting the pH value of 100 mL of the solution to be converted to 4.0 with 5% hydrochloric acid, 125 mg of sodium thiosulfate and 250 mg of potassium ferrocyanide were added. After the reaction, 10 mg of polyaluminium chloride was added for flocculation, and 5 mg of diatomaceous earth was added for filtration to obtain filtrate I. (2) Add cyanide treatment agent (35 parts of diatomaceous earth and 15 parts of polyaluminium chloride) to filtrate I, the mass volume ratio of cyanide treatment agent to filtrate I is 3 mg:100 mL, filter, concentrate the filtrate to obtain a concentrated solution; (3) The concentrated solution is loaded onto a macroporous resin and eluted first with water and then with a 50% by volume acetone aqueous solution. The acetone aqueous solution elution portion is collected to obtain the amount of vitamin B12.

[0023] The eluate from step (3) was measured by high performance liquid chromatography, where the content of vitamin B12 was 4751.3 μg / mL and the content of cyanide was 22.9 μg / L.

[0024] Embodiment 3: A method for preparing vitamin B12 with cyanide residue removed, the method comprising the following steps: (1) After adjusting the pH value of 100 mL of the solution to be converted to 4.0 with 5% hydrochloric acid, 50 mg of sodium thiosulfate and 150 mg of potassium ferrocyanide were added. After the reaction, 30 mg of polyaluminium chloride was added for flocculation. Then, 20 mg of diatomaceous earth was added for filtration to obtain filtrate I. (2) Add cyanide treatment agent (35 parts of diatomaceous earth and 15 parts of polyaluminium chloride) to filtrate I, the mass volume ratio of cyanide treatment agent to filtrate I is 8 mg:100 mL, filter, and concentrate the filtrate to obtain a concentrated solution; (3) The concentrated solution is loaded onto a macroporous resin and eluted first with water and then with a 50% by volume acetone aqueous solution. The acetone aqueous solution elution portion is collected to obtain the amount of vitamin B12.

[0025] The eluate of step (3) was measured by high performance liquid chromatography, wherein the content of vitamin B12 was 4591.7 μg / mL, and the content of cyanide in step (4) was 8.6 μg / L.

[0026] Comparative Example 1: A method for preparing vitamin B12 with cyanide residue removed, the method comprising the following steps: (1) After adjusting the pH value of 100 mL of the solution to be converted to 4.0 with 5% hydrochloric acid, 150 mg of potassium ferroxene was added, and after the reaction, 10 mg of polyaluminium chloride was added for flocculation, and 5 mg of diatomaceous earth was added for filtration to obtain filtrate I; (2) Add cyanide treatment agent (35 parts of diatomaceous earth and 15 parts of polyaluminium chloride) to filtrate I, the mass volume ratio of cyanide treatment agent to filtrate I is 5 mg:100 mL, filter, concentrate the filtrate to obtain a concentrated solution; (3) The concentrated solution is loaded onto a macroporous resin and eluted first with water and then with a 50% by volume acetone aqueous solution. The acetone aqueous solution elution portion is collected to obtain vitamin B12.

[0027] The contents of related substances were determined by high performance liquid chromatography, wherein the content of vitamin B12 in the eluate of step (3) was 3488.6 μg / mL, and the content of cyanide in step (4) was 11.1 μg / L.

[0028] Comparative Example 2: A method for preparing vitamin B12 with cyanide residue removed, the method comprising the following steps: (1) After adjusting the pH value of 100 mL of the solution to be converted to 4.0 with 5% hydrochloric acid, 30 mg of sodium thiosulfate and 170 mg of potassium ferrocyanide were added. After the reaction, 10 mg of polyaluminium chloride was added for flocculation, and 5 mg of diatomaceous earth was added for filtration to obtain filtrate I. (2) Add cyanide treatment agent (35 parts of diatomaceous earth and 15 parts of polyaluminium chloride) to filtrate I, the mass volume ratio of cyanide treatment agent to filtrate I is 5 mg:100 mL, filter, concentrate the filtrate to obtain a concentrated solution; (3) The concentrated solution is loaded onto a macroporous resin and eluted first with water and then with a 50% by volume acetone aqueous solution. The acetone aqueous solution elution portion is collected to obtain vitamin B12.

[0029] The eluate of step (3) was measured by high performance liquid chromatography, wherein the content of vitamin B12 was 3856.9 μg / mL, and the content of cyanide in step (4) was 13.4 μg / L.

[0030] Comparative Example 3: A method for preparing vitamin B12 with cyanide residue removed, the method comprising the following steps: (1) After adjusting the pH value of 100 mL of the solution to be converted to 4.0 with 5% hydrochloric acid, 50 mg of sodium thiosulfate and 150 mg of potassium ferrocyanide were added. After the reaction, 10 mg of polyaluminium chloride was added for flocculation, and 5 mg of diatomaceous earth was added for filtration to obtain filtrate I. (2) Concentrating the filtrate I to obtain a concentrated solution; (3) The concentrated solution is loaded onto a macroporous resin and eluted first with water and then with a 50% by volume acetone aqueous solution. The acetone aqueous solution elution portion is collected to obtain vitamin B12.

[0031] The contents of related substances were determined by high performance liquid chromatography, wherein the content of vitamin B12 in the eluate of step (3) was 4532.8 μg / mL, and the content of cyanide in step (4) was 176.4 μg / L.

[0032] According to the results of the determination of the content of vitamin B12 in the eluent of Examples 1-3 and Comparative Examples 1-3 and the content of cyanide in the wastewater, it can be seen that the combined use of sodium thiosulfate and potassium ferrocyanide in the liquid to be converted improves the conversion rate of vitamin B12; at the same time, the combined cyanide treatment agent composed of polyaluminium chloride and diatomaceous earth is used for treatment, which effectively reduces the content of cyanide in the product vitamin B12, thereby achieving a safe and environmentally friendly effect.

[0033] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing vitamin B12 from which cyanide residues are removed, the method comprising the following steps: (1) Adding sodium thiosulfate and potassium ferroxene to the liquid to be converted, flocculating and filtering to obtain filtrate I; (2) Adding a cyanide treatment agent consisting of polyaluminium chloride and diatomaceous earth to the filtrate I, filtering, and concentrating the filtrate to obtain a concentrated solution; (3) The concentrated solution is adsorbed by macroporous resin and analyzed by acetone aqueous solution to obtain vitamin B12.

2. The preparation method according to claim 1, characterized in that: In the step (1), the mass volume ratio of potassium ferroxanthate to the liquid to be converted is 1.5-2.5 mg:1 mL.

3. The preparation method according to claim 1, characterized in that: In the step (1), the mass ratio of sodium thiosulfate to potassium ferroxanthate is 1:2-3.

4. The preparation method according to claim 1, characterized in that: In the step (1), before adding sodium thiosulfate, the pH of the liquid to be converted is adjusted to 3-4 using 5% by mass hydrochloric acid.

5. The preparation method according to claim 1, characterized in that: The liquid to be converted in step (1) is a fermentation liquid primary extract concentrate, which is obtained by destroying the bacterial cell structure of the fermentation liquid, dissolving it in water, filtering, adsorbing, eluting and concentrating it.

6. The preparation method according to claim 1, characterized in that: In the step (1), a flocculant is added during flocculation, and a filter aid is added during filtration.

7. The preparation method according to claim 6, characterized in that: The flocculant is polyaluminium chloride, and the filter aid is diatomaceous earth.

8. The preparation method according to claim 1, characterized in that: The composition of the cyanide treating agent in step (2) is: 35-40 parts of diatomaceous earth and 5-15 parts of polyaluminium chloride.

9. The preparation method according to claim 1, characterized in that: In the step (2), the mass volume ratio of the cyanide treatment agent to the filtrate I is 3-8 mg:100 mL.

10. The preparation method according to claim 1, characterized in that: The volume concentration of the acetone aqueous solution in step (3) is 50-70%.