A method for removing plasticizers from natural vitamin E

Abstract

This application relates to the field of plasticizer removal technology, specifically a method for removing plasticizers from natural vitamin E, comprising the following steps: mixing natural vitamin E, an acidic catalyst, and methanol, maintaining a temperature of 100-200℃ and a pressure of 0.4-0.6MPa for a transesterification reaction for 1-3 hours, washing with deionized water 2-5 times to obtain a reaction solution; distilling the reaction solution to obtain plasticizer-free vitamin E; wherein the weight ratio of natural vitamin E, acidic catalyst, and methanol is 100:(1-4):(25-30); the transesterification reaction is carried out under a protective atmosphere; before mixing in step (1), a desiccant is added and / or dehydration under reduced pressure is performed to dry the natural vitamin E; the acidic catalyst is a mixture of sulfuric acid and benzenesulfonic acid. This application, through the combination of raw materials and reaction conditions, removes plasticizers from natural vitamin E without destroying vitamin E, thereby increasing the yield of natural vitamin E while reducing production costs, making it suitable for industrial production.

Description

Technical Field

[0001] This application relates to the field of plasticizer removal technology, specifically to a method for removing plasticizers from natural vitamin E. Background Technology

[0002] Plasticizers, also known as plasticizers or plasticizers, are polymeric additives that increase the plasticity of polymers when added to them. They are mainly used in the manufacture of various plastic products, such as food packaging materials, toys, medical blood bags, medical tubing, and vinyl flooring. The main components of plasticizers are phthalates, such as dibutyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP), and diisononyl phthalate (DINP). However, plasticizers are highly toxic to humans and other organisms. Studies by many scholars at home and abroad have shown that the toxicity of plasticizers is mainly manifested in five aspects: genotoxicity, embryotoxicity, reproductive toxicity, neurotoxicity, and immunotoxicity. In addition, phthalate compounds are also associated with diseases such as decreased lung function, obesity, diabetes, and hypothyroidism in adult men. Therefore, all countries have strict regulations on the content of plasticizers in food. The World Health Organization has set the tolerable daily intake of DEHP at 0.025 mg per kilogram. In June 2011, the former Ministry of Health of my country issued the "Letter from the General Office of the Ministry of Health on Notifying the Maximum Residue Limits of Phthalate Esters in Food and Food Additives (Health Office Supervision Letter

[2011] No. 551)," which stipulates that the maximum residue limits of di(2-ethylhexyl) phthalate, diisononyl phthalate, and di-n-butyl phthalate in food and food additives are 1.5 mg / kg, 9.0 mg / kg, and 0.3 mg / kg, respectively.

[0003] Vitamin E, also known as tocopherol or gestational vitamin, is a type of fat-soluble vitamin that is naturally found in food. It includes two main categories: tocopherols (α,β,γ,δ-tocopherol) and tocotrienols (α,β,γ,δ-tocotrienol). Vitamin E is one of the most important antioxidants and an important nutrient for the human body. However, it cannot be synthesized or is insufficiently supplied in the human body, so it needs to be extracted from plants rich in natural vitamin E. Natural vitamin E can be obtained from the deodorized distillate of vegetable oils such as soybean oil, which are rich in natural tocopherols, through a series of transformations, separations, distillations, and concentrations. However, while the deodorized distillate of vegetable oils is rich in vitamin E, it also contains plasticizers. Because plasticizers and vitamin E are very similar in polarity, solubility, and boiling point, it is difficult to completely separate plasticizers from tocopherols during the extraction and processing of natural vitamin E using general molecular distillation, solvent extraction, and adsorption separation techniques. This results in a high plasticizer content in the natural vitamin E product, which can reach 50-300 mg / kg, potentially affecting human health.

[0004] Currently, methods for removing plasticizers from natural vitamin E mainly include physical adsorption methods such as activated carbon or resin adsorption and solvent extraction, and chemical degradation methods such as catalytic hydrogenation or saponification under alkaline conditions. Using alkali to saponify esters, converting phthalates into harmless fatty acids, and then separating and purifying them, is a relatively effective method for removing plasticizers. However, vitamin E is a weak acid and is unstable and easily decomposed in alkali, resulting in less than ideal yields. Using strongly basic anion exchange resins to reduce plasticizers in vitamin E is a good method, but repeated use of the resin as an adsorbent can reduce its adsorption efficiency, affecting yield. Frequent resin replacement increases costs, making it unsuitable for large-scale industrial production. Summary of the Invention

[0005] This application aims to overcome at least one of the deficiencies of the prior art and provide a method for removing plasticizers from natural vitamin E. By combining raw materials and reaction conditions, plasticizers in natural vitamin E can be removed without destroying vitamin E, thereby increasing the yield of natural vitamin E while reducing production costs, making it suitable for industrial production.

[0006] In a first aspect, embodiments of this application provide a method for removing plasticizers from natural vitamin E, achieved through the following technical solution:

[0007] A method for removing plasticizers from natural vitamin E includes the following steps:

[0008] (1) Take natural vitamin E, acidic catalyst and methanol, keep the temperature at 100-200℃ and the pressure at 0.4-0.6MPa for 1-3 hours for transesterification, wash and get the reaction solution;

[0009] (2) The reaction solution was distilled to obtain vitamin E without plasticizers;

[0010] The weight ratio of the natural vitamin E, the acidic catalyst, and the methanol is 100:(1-4):(25-30).

[0011] A method for removing plasticizers from natural vitamin E according to an embodiment of this application has at least the following beneficial effects:

[0012] This application utilizes an acidic catalyst to induce a transesterification reaction between plasticizers and methanol, converting high-boiling-point plasticizers in natural vitamin E such as diisononyl phthalate, di(2-ethylhexyl) phthalate, and di-n-butyl phthalate into lower-boiling-point plasticizers such as dimethyl phthalate, isononol, 2-ethylhexanol, and n-butanol. This facilitates removal by distillation. After conversion into low-boiling-point impurities, the boiling point difference between the impurities and vitamin E is greater during distillation, reducing the risk of vitamin E loss. Furthermore, the lower boiling point reduces energy consumption during distillation.

[0013] This application removes plasticizers from natural vitamin E without the vitamin E participating in any chemical reaction, thus ensuring the natural quality of vitamin E. It also improves the production efficiency of vitamin E and increases the purity of the obtained plasticizer-free vitamin E.

[0014] The method for removing plasticizers from natural vitamin E presented in this application has a small process flow and is simple to operate, making it suitable for industrial production. It not only improves the purity of plasticizer-free vitamin E but also reduces production costs.

[0015] The washing process described in this application can remove additives, acidic catalysts, and other impurities from the reaction, thereby improving the purity of the obtained plasticizer-free vitamin E.

[0016] According to some embodiments of this application, the acidic catalyst includes at least one of sulfuric acid and organic sulfonic acid, for example, sulfuric acid. Sulfuric acid is inexpensive, readily available, easy to store, has a high boiling point and is not easily volatile, is simple to use, and is highly economical.

[0017] Furthermore, the acidic catalyst is a mixture of sulfuric acid and benzenesulfonic acid. Benzenesulfonic acid is a strong acid but lacks oxidizing properties; mixing sulfuric acid and benzenesulfonic acid can enhance the catalytic effect while reducing the occurrence of side reactions.

[0018] Furthermore, the weight ratio of the sulfuric acid to the benzenesulfonic acid is 1:(1-3), for example, the weight ratio of the sulfuric acid to the benzenesulfonic acid is 1:2.

[0019] Furthermore, the concentration of the sulfuric acid is 97.8-98.3%, for example, 98%. Concentrated sulfuric acid with a concentration of 98% has strong hygroscopic properties, enabling it to absorb water that may be generated during the reaction and improve the reaction conversion rate.

[0020] According to some embodiments of this application, the mixing method is stirring. Stirring can accelerate the mixing speed between raw materials, which is beneficial to the rapid progress of the reaction and reduces energy consumption in the reaction.

[0021] Furthermore, the stirring speed is 100-140 r / min, for example, the stirring speed is 120 r / min.

[0022] According to some embodiments of this application, the transesterification reaction is carried out under a protective gas atmosphere. The anaerobic environment of the protective gas can prevent vitamin E from being oxidized and destroyed during heating, which is beneficial for controlling the reaction process, reducing the occurrence of side reactions, and improving the purity of the obtained plasticizer-free vitamin E.

[0023] Furthermore, the protective gas is selected from nitrogen, helium, neon, and argon, for example, nitrogen. Nitrogen is widely available, has low production costs, and can create an anaerobic environment to prevent vitamin E from being oxidized and destroyed, thus reducing the occurrence of side reactions. Rare gases such as helium, neon, and argon are stable and do not readily participate in chemical reactions, which can reduce the formation of side reactions.

[0024] According to some embodiments of this application, the temperature of the transesterification reaction is 110-140°C. By setting the raw material composition and conditions such as reaction pressure and protective atmosphere, the heat utilization of this application is more efficient, and the transesterification reaction can be completed at 110-140°C, which helps to reduce energy consumption.

[0025] Furthermore, the temperature of the transesterification reaction is 120-130°C, for example, the temperature of the transesterification reaction is 120°C or 130°C.

[0026] According to some embodiments of this application, the pressure of the transesterification reaction is 0.45-0.55 MPa. A high-pressure environment is beneficial for promoting the transesterification reaction and increasing the reaction rate.

[0027] According to some embodiments of this application, the transesterification reaction takes 1.5-2.5 hours, for example, 2 hours. By selecting a suitable catalyst and setting reaction conditions suitable for this application, the transesterification reaction can be completed in 1.5-2.5 hours, improving production efficiency and reducing reaction consumption.

[0028] According to some embodiments of this application, before mixing in step (1), the natural vitamin E is further subjected to a drying process. Drying can reduce the water in the reaction system, promote the degree of transesterification reaction, and increase the conversion rate of diisononyl phthalate, di(2-ethylhexyl) phthalate, and di-n-butyl phthalate.

[0029] Furthermore, the drying process includes adding a desiccant and / or vacuum dehydration. Vacuum dehydration can improve drying efficiency while preventing the oxidation of vitamin E during the drying process.

[0030] Furthermore, the desiccant includes at least one of anhydrous calcium chloride and anhydrous magnesium sulfate. Anhydrous calcium chloride and anhydrous magnesium sulfate have strong drying capabilities and fast drying speeds, do not destroy vitamin E, and are also inexpensive, thus reducing production costs.

[0031] Furthermore, the amount of the desiccant used is 3-5% of the weight of the natural vitamin E, for example, 4% of the weight of the natural vitamin E.

[0032] According to some embodiments of this application, the washing in step (1) is performed 2-5 times, for example, 3 times. Multiple washings can better remove additives, acidic catalysts, and other impurities from the reaction, further improving the purity of the obtained plasticizer-free vitamin E.

[0033] According to some embodiments of this application, the washing temperature in step (1) is 50-100℃, for example, the washing temperature in step (1) is 80℃. Warm water washing allows for faster thermal motion of water molecules, which is beneficial for the diffusion of impurities. Furthermore, warm water can increase the solubility of impurity ions, thus improving the washing effect.

[0034] According to some embodiments of this application, the detergent used for washing in step (1) is water.

[0035] Furthermore, the washing agent used in step (1) is deionized water. Using deionized water, which does not contain ionic impurities, avoids introducing new impurities into the reaction solution and improves the purity of the obtained plasticizer-free vitamin E.

[0036] Further, the amount of detergent used in step (1) is 12.5-15% of the weight of natural vitamin E, for example, the amount of detergent used in step (1) is 15% of the weight of natural vitamin E.

[0037] According to some embodiments of this application, the distillation method in step (2) is molecular distillation. Molecular distillation operates at low temperatures and high vacuum, which can further avoid the decomposition of vitamin E by high-temperature heating. Moreover, the heating time is short, which can reduce the energy consumption during heating. At the same time, the separation efficiency is high, the separation process is physical separation, vitamin E is not easily contaminated, the original quality of natural vitamin E can be maintained, and it is not easy to cause the reaction and denaturation of vitamin E.

[0038] Furthermore, the molecular distillation includes primary molecular distillation and secondary molecular distillation. Primary molecular distillation mainly removes light phase components such as alcohols with low boiling points, while secondary molecular distillation removes dimethyl phthalate. Through two-stage molecular distillation, the purity of plasticizer-free vitamin E can be further improved.

[0039] Furthermore, the vacuum degree of the first-stage molecular distillation is 0.1-0.5 Pa.

[0040] Furthermore, the operating temperature of the primary molecular distillation is 160-200℃.

[0041] Furthermore, the vacuum degree of the secondary molecular distillation is 0.1-0.5 Pa.

[0042] Furthermore, the operating temperature of the secondary molecular distillation is 270-290°C.

[0043] According to some embodiments of this application, the weight ratio of the natural vitamin E, the acidic catalyst, and the methanol is 100:(3-4):(27-30), for example, the weight ratio of the natural vitamin E, the acidic catalyst, and the methanol is 100:3:27.

[0044] Secondly, embodiments of this application provide plasticizer-free vitamin E obtained by the above-described method for removing plasticizers from natural vitamin E.

[0045] The plasticizer-free vitamin E according to the embodiments of this application has at least the following beneficial effects:

[0046] The vitamin E obtained in this application, which is free of plasticizers, is less likely to cause harm to human health during use. It has high purity, can improve human resistance, prevent cancer, and when applied to products, can improve the antioxidant properties of the products, prevent spoilage and deterioration, and extend shelf life.

[0047] Thirdly, the embodiments of this application provide the application of the above-mentioned plasticizer-free vitamin E in food, medicine, or cosmetics. The plasticizer-free vitamin E obtained in this application does not contain plasticizers and will not harm human health when applied in the fields of food, medicine, or cosmetics. It can improve the antioxidant properties of food, cosmetics, and other products, and after being absorbed by the human body, it can prevent cancer and enhance immunity. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, a further detailed description will be provided below in conjunction with specific embodiments. The embodiments described herein are merely some examples of this application and should not be construed as limiting the scope of protection of this application.

[0049] Example 1

[0050] A method for removing plasticizers from natural vitamin E includes the following steps:

[0051] (1) Add 20g of anhydrous magnesium sulfate to 500g of natural vitamin E and dehydrate under reduced pressure. Take the treated natural vitamin E and mix it with 5g of 98% sulfuric acid, 10g of benzenesulfonic acid and 135g of methanol. Stir at a stirring speed of 120r / min, introduce nitrogen protective gas, and maintain the temperature at 120℃ and the pressure at 0.5MPa for 2h of ester exchange reaction. After the reaction is completed, wash it repeatedly 3 times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0052] (2) The obtained reaction solution was subjected to first-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and second-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E without plasticizer;

[0053] The obtained plasticizer-free vitamin E was tested, and the mass of the obtained plasticizer-free vitamin E was 464.3g, the yield of vitamin E was 92.86%, and plasticizers were not detected.

[0054] Example 2

[0055] A method for removing plasticizers from natural vitamin E includes the following steps:

[0056] (1) Add 24g of anhydrous magnesium sulfate to 600g of natural vitamin E and dehydrate and dry under reduced pressure. Take the treated natural vitamin E and mix it with 6g of 98% sulfuric acid, 12g of benzenesulfonic acid and 162g of methanol. Stir at a stirring speed of 120r / min, introduce nitrogen protective gas, and maintain the temperature at 120℃ and the pressure at 0.5MPa for 2h of ester exchange reaction. After the reaction is completed, wash it repeatedly 3 times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0057] (2) The obtained reaction solution was subjected to first-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and second-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E without plasticizer;

[0058] The obtained plasticizer-free vitamin E was tested, and the mass of the obtained plasticizer-free vitamin E was 553.62g, the yield of vitamin E was 92.27%, and plasticizers were not detected.

[0059] Example 3

[0060] A method for removing plasticizers from natural vitamin E includes the following steps:

[0061] (1) Add 20g of anhydrous magnesium sulfate to 500g of natural vitamin E and dehydrate under reduced pressure. Take the treated natural vitamin E and mix it with 5g of 98% sulfuric acid, 10g of benzenesulfonic acid and 135g of methanol. Stir at a stirring speed of 120r / min, introduce nitrogen protective gas, and maintain the temperature at 130℃ and the pressure at 0.5MPa for 2h of ester exchange reaction. After the reaction is completed, wash it repeatedly 3 times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0062] (2) The obtained reaction solution was subjected to first-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and second-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E without plasticizer;

[0063] The obtained plasticizer-free vitamin E was tested, and the mass of the obtained plasticizer-free vitamin E was 447.85g, the yield of vitamin E was 89.57%, and plasticizers were not detected.

[0064] Example 4

[0065] A method for removing plasticizers from natural vitamin E includes the following steps:

[0066] (1) Add 20g of anhydrous magnesium sulfate to 500g of natural vitamin E and dehydrate under reduced pressure. Take the treated natural vitamin E and mix it with 5g of 98% sulfuric acid, 10g of benzenesulfonic acid and 135g of methanol. Stir at a stirring speed of 120r / min, introduce nitrogen protective gas, and maintain the temperature at 120℃ and the pressure at 0.5MPa for 2.5h of transesterification reaction. After the reaction is completed, wash the mixture three times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0067] (2) The obtained reaction solution was subjected to first-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and second-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E without plasticizer;

[0068] The obtained plasticizer-free vitamin E was tested, and the mass of the obtained plasticizer-free vitamin E was 444.8g, the yield of vitamin E was 88.96%, and plasticizers were not detected.

[0069] Example 5

[0070] A method for removing plasticizers from natural vitamin E includes the following steps:

[0071] (1) Add 20g of anhydrous magnesium sulfate to 500g of natural vitamin E and dehydrate under reduced pressure. Take the treated natural vitamin E and mix it with 5g of 98% sulfuric acid, 15g of benzenesulfonic acid and 135g of methanol. Stir at a stirring speed of 120r / min, introduce nitrogen protective gas, and maintain the temperature at 120℃ and the pressure at 0.5MPa for 2h of ester exchange reaction. After the reaction is completed, wash it repeatedly 3 times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0072] (2) The obtained reaction solution was subjected to first-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and second-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E without plasticizer;

[0073] The obtained plasticizer-free vitamin E was tested, and the mass of the obtained plasticizer-free vitamin E was 448.4g, the yield of vitamin E was 89.68%, and plasticizers were not detected.

[0074] Example 6

[0075] A method for removing plasticizers from natural vitamin E includes the following steps:

[0076] (1) Add 20g of anhydrous magnesium sulfate to 500g of natural vitamin E and dehydrate under reduced pressure. Take the treated natural vitamin E and mix it with 10g of 98% sulfuric acid, 10g of benzenesulfonic acid and 150g of methanol. Stir at a stirring speed of 120r / min, introduce nitrogen protective gas, and maintain the temperature at 120℃ and the pressure at 0.5MPa for 2h of ester exchange reaction. After the reaction is completed, wash the mixture three times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0077] (2) The obtained reaction solution was subjected to first-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and second-stage molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E without plasticizer;

[0078] The obtained plasticizer-free vitamin E was tested, and the mass of the obtained plasticizer-free vitamin E was 459.1g, the yield of vitamin E was 91.82%, and plasticizers were not detected.

[0079] Comparative Example 1

[0080] A method for removing plasticizers from natural vitamin E includes the following steps:

[0081] (1) Add 20g of anhydrous magnesium sulfate to 500g of natural vitamin E and dehydrate under reduced pressure. Take the treated natural vitamin E and mix it with 5g of 98% sulfuric acid, 10g of benzenesulfonic acid and 75g of methanol. Stir at a stirring speed of 120r / min, introduce nitrogen protective gas, and maintain the temperature at 120℃ and the pressure at 0.5MPa for 2h of transesterification reaction. After the reaction is completed, wash the mixture three times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0082] (2) The obtained reaction solution was subjected to primary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and secondary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E after the reaction;

[0083] The obtained vitamin E after the reaction was tested. The mass of the obtained vitamin E after the reaction was 453.2g, and the yield of vitamin E was 90.64%. The concentrations of plasticizers di(2-ethylhexyl) phthalate were detected to be 8.6mg / kg, diisononyl phthalate 10.3mg / kg, and di-n-butyl phthalate 4.9mg / kg.

[0084] Comparative Example 2

[0085] A method for removing plasticizers from natural vitamin E includes the following steps:

[0086] (1) Add 20g of anhydrous magnesium sulfate to 500g of natural vitamin E and dehydrate under reduced pressure. Take the treated natural vitamin E and mix it with 5g of 98% sulfuric acid, 10g of benzenesulfonic acid and 135g of methanol. Stir at a stirring speed of 120r / min, introduce nitrogen protective gas, and maintain the temperature at 250℃ and the pressure at 0.5MPa for 2h of ester exchange reaction. After the reaction is completed, wash it repeatedly 3 times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0087] (2) The obtained reaction solution was subjected to primary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and secondary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E after the reaction;

[0088] The obtained vitamin E after the reaction was tested. The mass of the obtained vitamin E after the reaction was 418g, and the yield of vitamin E was 83.6%. The concentrations of plasticizers di(2-ethylhexyl) phthalate, diisononyl phthalate, and dibutyl phthalate were detected to be 4.5mg / kg, 6.6mg / kg, and 4.9mg / kg, respectively.

[0089] Comparative Example 3

[0090] A method for removing plasticizers from natural vitamin E includes the following steps:

[0091] (1) Add 20g of anhydrous magnesium sulfate to 500g of natural vitamin E and dehydrate under reduced pressure. Take the treated natural vitamin E and mix it with 5g of 98% sulfuric acid, 10g of benzenesulfonic acid and 135g of methanol. Stir at 120r / min and maintain the temperature at 120℃ and the pressure at 0.5MPa for 2h of transesterification reaction. After the reaction is completed, wash the mixture three times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0092] (2) The obtained reaction solution was subjected to primary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and secondary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E after the reaction;

[0093] The obtained vitamin E after the reaction was tested, and the mass of the obtained vitamin E was 381.75g, the yield of vitamin E was 76.35%, and no plasticizer was detected.

[0094] Comparative Example 4

[0095] A method for removing plasticizers from natural vitamin E includes the following steps:

[0096] (1) Mix 500g of natural vitamin E with 15g of 60% sulfuric acid and 135g of methanol and stir at a stirring speed of 120r / min. Purge with nitrogen protective gas and maintain the temperature at 120℃ and the pressure at 0.5MPa for 2h of transesterification reaction. After the reaction is completed, wash the mixture three times with 75ml of deionized water at 80℃ to obtain the reaction solution.

[0097] (2) The obtained reaction solution was subjected to primary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and secondary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain vitamin E after the reaction;

[0098] The obtained vitamin E after the reaction was tested. The mass of the obtained vitamin E after the reaction was 456.8g, and the yield of vitamin E was 91.36%. The concentrations of plasticizers di(2-ethylhexyl) phthalate were detected to be 3.1mg / kg, diisononyl phthalate 5.8mg / kg, and di-n-butyl phthalate 2.3mg / kg.

[0099] Comparative Example 5

[0100] A method for removing plasticizers from natural vitamin E includes the following steps:

[0101] (1) Take 500g of natural vitamin E and wash it repeatedly 3 times with 75ml of deionized water at 80℃ to obtain the washed natural vitamin E.

[0102] (2) The washed natural vitamin E was subjected to primary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 180 °C and secondary molecular distillation at a vacuum of 0.3 Pa and an operating temperature of 280 °C to obtain the treated vitamin E;

[0103] The obtained processed vitamin E was tested, and the mass of the processed vitamin E was 463.4 g, with a vitamin E yield of 92.68%. The concentrations of the plasticizers di(2-ethylhexyl) phthalate were detected to be 16.8 mg / kg, diisononyl phthalate 20.2 mg / kg, and di-n-butyl phthalate 18.4 mg / kg.

[0104] As can be seen from Examples 1-6 and Comparative Examples 1-5 of this application, the method for removing plasticizers from natural vitamin E in this application, through a specific combination of raw materials and reaction conditions, can not only remove plasticizers from natural vitamin E, but also improve the yield of vitamin E.

[0105] Compared with Example 1, Comparative Example 1 reduced the amount of methanol added. It can be seen that the concentration of plasticizers in the obtained vitamin E after the reaction was 8.6 mg / kg for di(2-ethylhexyl) phthalate, 10.3 mg / kg for diisononyl phthalate, and 4.9 mg / kg for di-n-butyl phthalate, all of which exceeded the standard. This indicates that the amount of methanol added was too small, which would lead to the plasticizers not being completely removed.

[0106] Compared with Example 1, Comparative Example 2 increased the temperature of the transesterification reaction. It can be seen that the concentration of plasticizers in the vitamin E after the reaction is 4.5 mg / kg for di(2-ethylhexyl) phthalate, 6.6 mg / kg for diisononyl phthalate, and 4.9 mg / kg for di-n-butyl phthalate. This indicates that adjusting the reaction temperature will change the reaction process and reduce the removal rate of plasticizers.

[0107] Compared with Example 1, no protective gas was introduced during the reaction in Comparative Example 3. It can be seen that the yield of vitamin E after the reaction was significantly reduced. This indicates that without the introduction of a protective gas, some vitamin E will be destroyed by the reaction, resulting in a decrease in the yield of vitamin E.

[0108] Compared with Example 1, Comparative Example 4 did not perform a pre-drying treatment on the natural vitamin E in the reaction. It can be seen that the concentration of plasticizers in the vitamin E after the reaction is 3.1 mg / kg for di(2-ethylhexyl) phthalate, 5.8 mg / kg for diisononyl phthalate, and 2.3 mg / kg for di-n-butyl phthalate. This indicates that the presence of water in the raw materials will affect the reaction process and reduce the removal rate of plasticizers.

[0109] Compared with Example 1, Comparative Example 5 did not undergo transesterification. It can be seen that the concentration of plasticizers in the treated vitamin E was 16.8 mg / kg for di(2-ethylhexyl) phthalate, 20.2 mg / kg for diisononyl phthalate, and 18.4 mg / kg for di-n-butyl phthalate. The content of plasticizers is significantly higher than the standards for food and food additives. This indicates that the present application can effectively remove plasticizers from natural vitamin E through transesterification by a specific combination of raw materials and reaction conditions.

[0110] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions or alterations can be made to these embodiments without departing from the principles and spirit of this application, and the technical solutions resulting from such changes, modifications, substitutions or alterations will all fall within the protection scope of this application.

Claims

1. A method for removing plasticizers from natural vitamin E, characterized in that, Includes the following steps: (1) Take natural vitamin E, acid catalyst and methanol, keep the temperature at 100-200℃ and the pressure at 0.4-0.6MPa for 1-3h transesterification reaction, wash with deionized water 2-5 times to obtain reaction solution; (2) The reaction solution was subjected to molecular distillation to obtain vitamin E without plasticizers; The weight ratio of the natural vitamin E, the acidic catalyst, and the methanol is 100:(1-4):(25-30). The transesterification reaction was carried out under a protective atmosphere; Before mixing in step (1), the natural vitamin E is dried by adding a desiccant and dehydrating under reduced pressure. The acid catalyst is a mixture of sulfuric acid and benzenesulfonic acid in a weight ratio of 1:(1-3); The molecular distillation includes primary molecular distillation and secondary molecular distillation, wherein the vacuum degree of the primary molecular distillation is 0.1-0.5 Pa and the operating temperature is 160-200℃, and / or the vacuum degree of the secondary molecular distillation is 0.1-0.5 Pa and the operating temperature is 270-290℃. The concentration of the sulfuric acid is 97.8-98.3%.

2. The method of claim 1, wherein the plasticizer is removed from natural vitamin E by the process of, The weight ratio of the natural vitamin E, the acidic catalyst, and the methanol is 100:(3-4):(27-30).

3. The method of claim 1, wherein the plasticizer is removed from natural vitamin E by, In step (1), the natural vitamin E, acid catalyst, and methanol are mixed by stirring at a speed of 100-140 r / min.

4. The method of claim 1, wherein the plasticizer is removed from natural vitamin E by, The protective gas is selected from nitrogen, helium, neon, and argon.

5. The method of claim 1, wherein the plasticizer is removed from natural vitamin E by the process comprising: The washing temperature in step (1) is 50-100℃.

6. The method for removing plasticizers from natural vitamin E according to claim 1, characterized in that, The desiccant is selected from at least one of anhydrous calcium chloride and anhydrous magnesium sulfate, and / or the amount of the desiccant is 3-5% of the weight of the natural vitamin E.

7. The method for removing plasticizers from natural vitamin E according to claim 1, characterized in that, The temperature of the transesterification reaction is 110-140℃.