Method for reducing aldehydes and ketones in glycerol

Abstract

The invention discloses a method for reducing aldehydes and ketones in glycerol, which comprises the following steps: taking glycerol to be treated as a raw material, and dissolving the glycerol in a solvent to obtain a mixed solution; adding sodium borohydride and sodium methoxide into the obtained mixed solution, and stirring for reaction to obtain a product solution; filtering the obtained product solution to obtain filtrate; and carrying out reduced pressure distillation on the obtained filtrate to obtain a final product. According to the invention, the reduction effect of the specific reducibility of sodium borohydride on aldehyde ketone substances is utilized, so that the aldehyde ketone substances in the glycerol finished product can be effectively reduced. The process is simple, and the obtained glycerol product is high in purity and good in stability and can be widely applied to preparation production and medicine formulas.

Description

Technical Field

[0001] The invention belongs to the technical field of refining and purifying compounds, and in particular relates to a method for reducing aldehydes and ketones in glycerol. Background Art

[0002] Glycerol, also known as glycerol, is an organic compound with the chemical formula C3H8O3. It is a simple polyol compound. It is a colorless, odorless, sweet, viscous liquid and non-toxic. The glycerol backbone is found in lipids called glycerides. It is widely used in FDA-approved wound and burn treatments due to its antibacterial and antiviral properties. Conversely, it is also used as a bacterial culture medium. It can be used as an effective marker to measure liver disease. Due to its three hydroxyl groups, glycerol is miscible with water and is hygroscopic.

[0003] Glycerol is a common polyol that exists widely in various organisms in nature. It plays an important role in sugar metabolism and cell signal transduction, and participates in various biochemical reactions in organisms. In addition, glycerol is also widely used in industrial production, especially in the manufacture of daily chemicals, food and medicine. They can not only be used as moisturizers and stabilizers, but also have special biological activity functions in some cases.

[0004] The structural characteristics of glycerol determine its chemical properties and application value. Because it contains multiple hydroxyl groups, glycerol can play a variety of roles in chemical reactions, such as forming hydrogen bonds and participating in esterification reactions. These characteristics make glycerol irreplaceable in the fields of cosmetics, medicines, and food additives. For example, in cosmetics, glycerol can be used as a moisturizer to help the skin retain moisture; in the food industry, glycerol can be used as a sweetener or stabilizer to improve the taste and quality of food. In short, glycerol plays an important role in many fields due to its unique structure and properties.

[0005] In addition, glycerol is also widely used in pharmaceutical technology. With the development of modern medicine, some drug formulations have put forward requirements for aldehydes and ketones. In order to reduce adverse reactions to the human body and slow down the degradation of the preparations, the content of aldehydes and ketones needs to be controlled within an extremely low range. In order to meet the needs of preparations, the relevant preparation raw materials need to have more stringent control over this indicator and control the content of aldehydes and ketones in glycerol within an extremely low range.

[0006] Sodium borohydride is an inorganic compound with the chemical formula NaBH4. It is a white to off-white crystalline powder with strong hygroscopicity. Its alkaline solution is brown-yellow. It is one of the most commonly used reducing agents. Normally, sodium borohydride cannot reduce esters, amides, carboxylic acids and nitrile compounds, but when there is a heteroatom at the α position of the carbonyl group of the ester, it can reduce the ester. It is usually used as a reducing agent for aldehydes, ketones, and acyl chlorides, a foaming agent in the plastics industry, a bleaching agent for papermaking, and a hydrogenating agent for the manufacture of dihydrostreptomycin in the pharmaceutical industry. Summary of the invention

[0007] The primary purpose of the present invention is to provide a method for reducing aldehydes and ketones in glycerol, so as to utilize the specific reducing property of sodium borohydride to reduce the aldehydes and ketones content in the glycerol product.

[0008] To this end, the present invention provides the following technical solutions.

[0009] One aspect of the present invention provides a method for reducing aldehydes and ketones in glycerol, the method comprising the following steps:

[0010] Taking the glycerol to be treated as a raw material, dissolving the glycerol in a solvent to obtain a mixed solution;

[0011] Adding sodium borohydride and sodium methoxide to the obtained mixed solution, stirring for reaction, and obtaining a product solution;

[0012] The obtained product solution is filtered to obtain a filtrate;

[0013] The obtained filtrate was distilled under reduced pressure to obtain the final product.

[0014] In a preferred embodiment of the present invention, the solvent is methanol and / or ethanol;

[0015] In a preferred embodiment of the present invention, the amount of the solvent added is 0.5 to 1 times the mass of the glycerol.

[0016] In a preferred embodiment of the present invention, the amount of sodium borohydride added is 20 to 1000 ppm based on the mass of glycerol.

[0017] In a preferred embodiment of the present invention, the amount of sodium methoxide added is 0-0.5% of the mass of glycerol.

[0018] In a preferred embodiment of the present invention, the stirring reaction conditions are: temperature 20-40° C., time 1-4 h.

[0019] In a preferred embodiment of the present invention, the filtration is carried out using a 0.22 μm polytetrafluoroethylene filter membrane.

[0020] In a preferred embodiment of the present invention, the cutting temperature of the pre-decompression distillation fraction is 80-140° C., and the cutting time is 10-30 min.

[0021] In a preferred embodiment of the present invention, the receiving temperature of the vacuum distillation finished product is 120-180°C, and the receiving time of the finished product is 4-8h.

[0022] Another aspect of the present invention also provides a purified glycerol obtained according to the method as described above, wherein the content of aldehydes and ketones in the purified glycerol is less than 10 ppm.

[0023] By means of the above technical solution, the present invention has at least the following advantages:

[0024] The present invention utilizes the specific reducing property of sodium borohydride and the reducing effect on aldehydes and ketones, and uses sodium borohydride in the refining and purification of glycerol, thereby achieving the purpose of reducing the aldehyde and ketone content in the glycerol product. The glycerol product refined by the method of the present invention has high glycerol purity, and the aldehyde and ketone content therein is extremely low, which can reach less than 10ppm. The method of the present invention has simple process, and the obtained product has high purity and good stability, and is mainly used in preparations and drug formulations, thereby further reducing the side effects of downstream products.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION

[0026] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0027] Unless otherwise specified, the percentage content involved in the present invention refers to mass percentage for solid-liquid mixing and solid-solid mixing, and refers to volume percentage for liquid-liquid mixing.

[0028] Unless otherwise specified, the percentage concentrations referred to in the present invention all refer to the final concentration, which refers to the percentage of the added component in the system after the addition of the component.

[0029] The temperature parameters in the present invention, if not specifically limited, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the precision range controlled by the instrument.

[0030] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0031] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0032] Unless otherwise specified, the glycerol used in the present invention is commercially available food grade / industrial grade glycerol, and the commercially available glycerol samples used in the examples are all of the same kind.

[0033] Embodiment 1:

[0034] Take 100g of commercially available glycerol sample, add 50g of methanol to dissolve, and obtain a glycerol / methanol mixed solution. Add 0.1g of sodium borohydride to the obtained glycerol / methanol mixed solution, stir at room temperature for 1 hour to obtain a product solution. The obtained product solution is precisely filtered through a 0.22μm filter membrane to obtain a filtrate. The obtained filtrate is subjected to reduced pressure distillation at 100℃ for 30min to cut off the front fraction, and then subjected to reduced pressure distillation at 150℃ for 8 hours to receive the finished product to obtain a purified glycerol product. The content of aldehydes and ketones in the obtained purified glycerol product is shown in Table 1 after detection by high performance liquid chromatography.

[0035] Table 1 Composition and content of purified glyceraldehyde ketone

[0036]

[0037] Embodiment 2:

[0038] Take 100g of commercially available glycerol sample, add 50g of ethanol to dissolve, and obtain a glycerol / ethanol mixed solution. Add 0.05g of sodium borohydride to the obtained glycerol / ethanol mixed solution, stir at room temperature for 4 hours to obtain a product solution. The obtained product solution is precisely filtered through a 0.22μm filter membrane to obtain a filtrate. The obtained filtrate is subjected to reduced pressure distillation at 140℃ for 20min to cut off the front fraction, and then subjected to reduced pressure distillation at 180℃ for 4 hours to receive the finished product to obtain a purified glycerol product. The content of aldehydes and ketones in the obtained purified glycerol product is shown in Table 2 after detection by high performance liquid chromatography.

[0039] Table 2 Composition and content of purified glyceraldehyde ketone

[0040]

[0041] Embodiment 3:

[0042] Take 100g of commercially available glycerol sample, add 0.002g of sodium borohydride, then add 0.26g of sodium methoxide, stir at room temperature for 1 hour to obtain a product solution. The obtained product solution is finely filtered through a 0.22μm filter membrane to obtain a filtrate. The obtained filtrate is subjected to reduced pressure distillation at 120℃ for 30min to cut off the front fraction, and then subjected to reduced pressure distillation at 160℃ for 5 hours to receive the finished product to obtain a purified glycerol product. The content of aldehydes and ketones in the obtained purified glycerol product is shown in Table 3 after detection by high performance liquid chromatography.

[0043] Table 3 Composition and content of purified glyceraldehyde ketone

[0044]

[0045] Comparative Example 1:

[0046] Take 100g of commercially available glycerol sample, add 0.002g of sodium borohydride, stir at room temperature for 1 hour to obtain a product solution. The obtained product solution is precisely filtered through a 0.22μm filter membrane to obtain a filtrate. The obtained filtrate is subjected to reduced pressure distillation at 120℃ for 30min to cut off the front fraction, and then subjected to reduced pressure distillation at 160℃ for 5 hours to receive the finished product to obtain a purified glycerol product. The content of aldehydes and ketones in the obtained purified glycerol product is shown in Table 4 after detection by high performance liquid chromatography.

[0047] Table 4 Composition and content of purified glyceraldehyde ketone

[0048]

[0049] Comparative Example 2:

[0050] Take 100g of commercially available glycerol sample, add 50g of ethanol to dissolve, and obtain a glycerol / ethanol mixed solution. Add 1g of silica gel (purchased from Sinopharm Chemical Reagent Co., Ltd., specification: 200-300 mesh) to the obtained glycerol / ethanol mixed solution, stir at room temperature for 4 hours to obtain a product solution. The obtained product solution is finely filtered through a 0.22μm filter membrane to obtain a filtrate. The obtained filtrate is subjected to reduced pressure distillation at 140℃ for 20min to cut off the front fraction, and then subjected to reduced pressure distillation at 180℃ for 4 hours to receive the finished product to obtain a purified glycerol product. The content of aldehydes and ketones in the obtained purified glycerol product is shown in Table 5 after detection by high performance liquid chromatography.

[0051] Table 5 Composition and content of purified glyceraldehyde ketone

[0052]

[0053]

[0054] Comparative Example 3:

[0055] Take 100g of commercially available glycerol sample, add 50g of ethanol to dissolve, and obtain a glycerol / ethanol mixed solution. Add 5g of cationic adsorption resin (Tianjin Jinda Zhengtong, specification: D001) to the obtained glycerol / ethanol mixed solution, stir at room temperature for 4 hours to obtain a product solution. The obtained product solution is finely filtered through a 0.22μm filter membrane to obtain a filtrate. The obtained filtrate is subjected to reduced pressure distillation at 140℃ for 20min to cut off the front fraction, and then subjected to reduced pressure distillation at 180℃ for 4 hours to receive the finished product to obtain a purified glycerol product. The content of aldehydes and ketones in the obtained purified glycerol product is shown in Table 6 after detection by high performance liquid chromatography.

[0056] Table 6 Composition and content of purified glyceraldehyde ketone

[0057]

[0058] It can be seen from the results in Tables 1 to 6 that the content of aldehydes and ketones in the purified glycerol obtained by the methods of Examples 1 to 3 of the present invention is significantly lower than that of Comparative Examples 1 to 3. The above results show that the method of the present invention can effectively reduce the content of aldehydes and ketones in glycerol.

[0059] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for reducing aldehydes and ketones in glycerol, characterized in that: The method comprises the following steps: Taking the glycerol to be treated as a raw material, dissolving the glycerol in a solvent to obtain a mixed solution; Adding sodium borohydride and sodium methoxide to the obtained mixed solution, stirring for reaction, and obtaining a product solution; The obtained product solution is filtered to obtain a filtrate; The obtained filtrate was distilled under reduced pressure to obtain the final product.

2. The method according to claim 1, characterized in that The solvent is methanol and / or ethanol.

3. The method according to claim 1, characterized in that: The amount of the solvent added is 0.5 to 1 times the mass of the glycerol.

4. The method according to claim 1, characterized in that: The amount of sodium borohydride added is 20-1000ppm based on the mass of glycerol.

5. The method according to claim 1, characterized in that The amount of sodium methoxide added is 0-0.5% of the mass of glycerol.

6. The method according to claim 1, characterized in that The stirring reaction conditions are: temperature 20-40° C., time 1-4 h.

7. The method according to claim 1, characterized in that The filtration is carried out using a 0.22 μm polytetrafluoroethylene filter membrane.

8. The method according to claim 1, characterized in that The cutting temperature of the pre-distillation fraction under reduced pressure is 80-140° C., and the cutting time is 10-30 min.

9. The method according to claim 1, characterized in that: The receiving temperature of the reduced pressure distillation finished product is 120~180℃, and the receiving time of the finished product is 4~8h.

10. The purified glycerol obtained according to the method according to any one of claims 1 to 9, characterized in that The content of aldehydes and ketones in the purified glycerol is less than 10 ppm.

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