E-liquid with low tsnas content and preparation method thereof

Abstract

The present application relates to a kind of electronic cigarette tobacco with low TSNAs content and its preparation method, the component of the electronic cigarette tobacco, glycerol is 30-40 parts by weight;Propylene glycol is 30-48 parts by weight;Deionized water is 5-10 parts by weight;Tobacco extract is 2-6 parts by weight;Nicotine is 1-2 parts by weight;Tobacco essence is 1-4 parts by weight;Flavoring additive is 0.5-1.0 parts by weight;Antioxidant is 2-3 parts by weight.The tobacco of the present application can effectively reduce the content of TSNAs, reduce the carcinogenic risk of electronic cigarette smoking and other smoking hazards;Help to enhance the tobacco aroma of electronic cigarette tobacco, improve the taste of smoking.

Description

Technical Field

[0001] This invention belongs to the field of electronic cigarette e-liquid technology, and in particular relates to the technical field of an electronic cigarette e-liquid with low TSNA content and its preparation method. Background Technology

[0002] E-cigarette liquids are composed of propylene glycol, glycerin, nicotine, tobacco extracts, and other additives. The addition of nicotine extracted from tobacco may introduce a large amount of nicotine compounds, the composition and content of which have a significant impact on the sensory and safety aspects of tobacco. Simultaneously, nicotine compounds can directly stimulate the human central nervous system, producing physiological responses. Tobacco alkaloids are easily metabolized into nitrosamines during tobacco processing and other processes. These nitrosamines then combine with nitrites to form tobacco-specific nitrosamines (TSNAs), which are highly carcinogenic. Currently, eight TSNAs have been identified: N-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), N-nitrosoanabasine (NAB), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), 4-(methylnitrosamino)-4-(3-pyridyl)-1-butanol (iso-NNAL), and 4-(methylnitrosamino)-4-3-pyridyl)butanol. The compounds include iso-NNAC (acid), 4-(methylnitrosamino)-4-(3-pyridyl)-butanal (NNA), among which NNN, NNK, NAB, and NAT are present in higher amounts and have stronger carcinogenicity.

[0003] NNN and NNK are major derivatives of nicotine and are the most abundant and most potent alkylating agent tobacco carcinogens among TSNAs. The International Agency for Research on Cancer (IARC) classifies them as Group 1 carcinogens. Although e-cigarettes contain less TSNAs than traditional tobacco, they still accumulate with long-term use. Furthermore, during inhalation, nitrites in saliva and nitrogen oxides in inhaled smoke also contribute to the formation of TSNAs, further increasing the risk of cancer. Currently, efforts are primarily focused on optimizing tobacco fermentation or distillation processes to reduce TSNA formation.

[0004] This application discovers that adding antioxidants such as vitamin C can reduce their content. During inhalation, vitamin C in the human body's serum can also combine with a certain amount of oxidative carcinogens such as nitric oxide, nitrosamines, and formaldehyde in the cigarette smoke, thereby transforming them into non-toxic compounds or non-mutagenic substances that are eliminated from the body. Tobacco products are free radical generators, and vitamins can inhibit the generation of free radicals, protecting somatic cells from damage and further reducing the risk of cancer. A search revealed that existing inventions, including an electronic cigarette e-liquid containing tea extract and its preparation method (CN104397871 B), an antioxidant electronic cigarette e-liquid and its preparation method (CN114617287 A), and an electronic cigarette e-liquid containing tea extract and traditional Chinese medicine extract and its preparation method (CN106387989 A), while involving vitamin C, do not elaborate on or demonstrate its function in reducing TSNA content.

[0005] The national mandatory standard for e-cigarettes, GB 41700-2022, stipulates that the atomized product should contain nicotine with a purity greater than 99%. Therefore, the formation of nicotine derivatives NNN and NNK is unavoidable. Consequently, it is necessary to optimize the e-liquid composition to minimize the reaction between nicotine and nitrites, and to remove TSNAs from tobacco extracts to reduce their content, thus developing an e-cigarette e-liquid with low TSNA content. Summary of the Invention

[0006] This invention aims to address the aforementioned problems and deficiencies by providing an e-cigarette e-liquid with low TSNA content and its preparation method. Based on compliance with GB 41700-2022, this invention involves treating tobacco extracts with liquid-phase adsorption of TSNAs, then adding the treated tobacco extract to the e-liquid and improving the e-liquid formulation to develop an e-cigarette e-liquid with low TSNA content, thereby reducing the risk of cancer.

[0007] The present invention is implemented using the following technical solution.

[0008] An e-cigarette liquid with low TSNA content comprises the following components in the following weight ratios: glycerin: 30-40 parts; propylene glycol: 30-48 parts; deionized water: 5-10 parts; tobacco extract: 2-6 parts; nicotine: 1-2 parts; tobacco flavoring: 1-4 parts; flavoring additives: 0.5-1.0 parts; antioxidants: 2-3 parts;

[0009] By employing the above technical solution, when nicotine is added to e-liquid, antioxidants such as vitamin C are added to promote the adsorption of nitrites from different sources, thereby reducing the content of TSNAs formed by the reaction of nicotine and nitrites. Furthermore, the added tobacco extract undergoes liquid-phase adsorption of TSNAs, directly reducing the TSNA content in the e-liquid. By directly or indirectly reducing the TSNA content in e-liquid through these two methods, the carcinogenic risk from vaping can be lowered.

[0010] Preferably, it is formulated from the following raw materials in parts by weight: glycerin: 35-40 parts; propylene glycol: 45-50 parts; deionized water: 5-8 parts; tobacco extract: 2-6 parts; nicotine: 1-2 parts; tobacco flavoring: 1%-2 parts; aroma additives: 0.5-1.0 parts; antioxidants: 2.5-3 parts;

[0011] Preferably, the tobacco extract is obtained by extracting the following raw materials in parts by weight: 1-5 parts tobacco leaves, 10-40 parts deionized water, 1.2-4.8 parts vitamin C, 5-10 parts adsorbent, 10-30 parts ethyl acetate, and 1-5 parts alcohol.

[0012] As a preferred embodiment, the tobacco extract is treated with liquid-phase adsorption TSNAs as follows: Dried Burley tobacco is added to deionized water containing 12% (by mass) vitamin C and soaked at 65°C in the dark for 24 hours. The solution is then filtered and separated to obtain filtrate A. Adsorbent is added at a solid-liquid ratio of 5:1, and the mixture is stirred in a water bath at 30°C in the dark for 1 hour. The mixture is then centrifuged to obtain supernatant B. Supernatant B is extracted three times with ethyl acetate to obtain extract C. Extract C is dried under reduced pressure, concentrated, and then dissolved in alcohol to obtain the tobacco extract.

[0013] By adopting the above technical solution, when performing liquid-phase adsorption and extraction of tobacco extracts, the aim is to reduce the content of TSNAs without reducing the content of main components and aroma substances. Ethyl acetate extraction can effectively remove impurities such as macromolecular proteins, inorganic salts, organic acid salts, and pigments, avoiding the generation of spicy, bitter, and irritating tastes, while increasing the aroma and taste of e-liquid.

[0014] Preferably, the weight ratio of glycerol to propylene glycol is 1:(1-1.2).

[0015] Preferably, the aroma additive is prepared by dissolving 500 mg of solanone and 750 mg of megastigmatrienone in 100 ml of alcohol.

[0016] By employing the above technical solutions, the specific gravity of glycerin is reduced, thereby decreasing the amount of water absorbed by glycerin in saliva after inhalation, lowering the concentration of nitrite, slowing its reaction rate with nicotine, and reducing the content of NNN and NNK. Adding flavoring substances can further enhance the tobacco aroma of e-cigarette liquids and improve the inhalation experience.

[0017] A method for preparing e-cigarette liquid with low TSNA content includes the following preparation steps:

[0018] S1: Weigh out glycerin, propylene glycol, and tobacco extract and mix them evenly to prepare a mother liquor;

[0019] S2: Dissolve nicotine and antioxidants in deionized water, then add them to the mother liquor and dissolve them completely to obtain a mixed solution;

[0020] S3: Weigh out the tobacco flavoring and aroma additives and add them to the mixture. Stir well and age for 24 hours to obtain e-cigarette oil with low TSNA content.

[0021] The beneficial effects of this invention are as follows:

[0022] (1) The e-cigarette e-liquid of this application improves the existing e-liquid formula, slows down the TSNAs content produced after inhalation, or directly reduces the TSNAs content of the e-liquid itself, thereby reducing the carcinogenic risk of inhaling e-cigarettes.

[0023] (2) The e-cigarette liquid of this application contains antioxidants such as vitamin C, which helps to adsorb toxic and harmful substances such as carbon monoxide, nitrosamines, and formaldehyde in the smoke aerosol and supplement the deficiency of vitamin C in the serum.

[0024] (3) The e-cigarette liquid of this application helps to enhance the tobacco aroma of the e-cigarette liquid and improve the smoking experience.

[0025] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the preparation method steps of the present invention. Detailed Implementation

[0027] The following embodiments are only a part of the technical solutions of the present invention and are not intended to limit all the technical solutions of the present invention. The embodiments of the present invention are provided to further explain and illustrate the details of the technical solutions of the present invention.

[0028] The raw materials used in this application are as follows: vegetable glycerol (VG) (Procter & Gamble); propylene glycol (PG) (Dow Chemical Company); deionized water (Wahaha); vitamin C was provided by Beijing Puxitang Biotechnology Co., Ltd.; H-type mordenite (SiO2 / Al2O3=25) was provided by Tianjin Nanhua Catalyst Co., Ltd.; the remaining reagents were all commercially available AR grade; nicotine, tobacco flavoring, aroma additives (purity >99%), burley tobacco leaves (Example 1) and modified burley tobacco shreds (Example 2) were provided by Yunnan Tobacco Science Research Institute.

[0029] Example 1

[0030] (1) Preparation of tobacco extract

[0031] Burley tobacco leaves were shredded and sterilized under ultraviolet light. 100g of shredded tobacco was added to 1000mL of deionized water containing 12g of vitamin C and soaked at 65℃ in the dark for 24 hours. The solution was filtered to obtain extract A. Extract A was diluted to 1000mL, and 100mL of extract A was added in portions to 500g of adsorbent (H-type mordenite zeolite) and stirred in a 30℃ water bath in the dark for 1 hour. The mixture was then centrifuged at 5000rpm for 10 minutes to obtain supernatant B. 1000mL of supernatant B was extracted three times with 3000mL of ethyl acetate. The three extracts were combined, dried under reduced pressure, and concentrated. The concentrated solids were then diluted at a ratio of 1:1 with alcohol to obtain the tobacco extract.

[0032] (2) Preparation of an e-liquid with low TSNA content

[0033] Weigh out 40g of glycerin, 45g of propylene glycol, and 5g of tobacco extract, mix them evenly, and prepare a mother liquor for later use; weigh out 1g of nicotine and 200mg of vitamin C, dissolve them in 50mL of deionized water, and then add them to the mother liquor and dissolve them completely to obtain a mixed solution; weigh out 500mg of tobacco flavoring and 500mg of aroma additives, add them to the mixed solution, stir evenly, and age for 24h to obtain e-cigarette oil with low TSNA content 1.

[0034] Example 2

[0035] (1) Preparation of tobacco extract

[0036] Weigh 100g of prepared Burley tobacco shreds and add them to 1000mL of deionized water containing 12g of vitamin C. Soak in the solution at 65℃ in the dark for 24 hours, then filter to obtain extract A. Adjust the volume of extract A to 1000mL, and add 500g of adsorbent (H-type mordenite) to 100mL of extract A in portions. Stir and adsorb in a 30℃ water bath in the dark for 1 hour, then centrifuge at 5000rpm for 10 minutes to obtain supernatant B. Take 1000mL of supernatant B and extract three times with 3000mL of ethyl acetate. Combine the three extracts, dry under reduced pressure, and concentrate. Then dilute with a solid-to-ethanol ratio of 1:1 to obtain the tobacco extract.

[0037] The modulation method described in this invention is a conventional existing technology, consistent with the modulation methods of commercially available cigarettes. Commercially available cigarette modulation methods generally include the following steps: fresh tobacco leaves are roasted, fermented, trimmed and shredded, and flavored. The modulation method described in this invention does not contain any special parameters and does not constitute a technical limitation to the invention's innovation. It is only used here as a comparative condition for distinguishing between those with and without modulation treatment, for subsequent TSNA content analysis.

[0038] (2) Preparation of an e-liquid with low TSNA content

[0039] Weigh out 40g of glycerin, 45g of propylene glycol, and 5g of tobacco extract, mix them evenly, and prepare a mother liquor for later use; weigh out 1g of nicotine and 200mg of vitamin C, dissolve them in 50mL of deionized water, and then add them to the mother liquor to dissolve them completely to obtain a mixed solution; weigh out 500mg of tobacco flavoring and 500mg of aroma additives, add them to the mixed solution, stir evenly, and age for 24h to obtain e-cigarette oil with low TSNA content 2.

[0040] Comparative Example 1

[0041] Following the e-cigarette oil preparation steps of Example 1, the tobacco extract was prepared without using an adsorbent (H-type mordenite) for liquid-phase adsorption of TSNAs; the remaining raw materials, amounts, and preparation methods were exactly the same.

[0042] Comparative Example 2

[0043] Following the e-cigarette oil preparation steps of Example 2, no adsorbent (H-type mordenite) was used for liquid-phase adsorption of TSNAs when preparing the tobacco extract; the other raw materials, amounts, and preparation methods were exactly the same.

[0044] Comparative Example 3

[0045] Following the e-cigarette oil preparation steps of Example 1, activated carbon was used as an adsorbent for liquid-phase adsorption of TSNAs when preparing the tobacco extract. The other raw materials, amounts, and preparation methods were exactly the same.

[0046] Comparative Example 4

[0047] Following the e-cigarette oil preparation steps of Example 2, activated carbon was used as an adsorbent for liquid-phase adsorption of TSNAs when preparing the tobacco extract. The other raw materials, amounts, and preparation methods were exactly the same.

[0048] TSNAs content determination

[0049] The prepared e-liquid was added to an electronic cigarette, and aerosol collection was performed using a 10-channel linear vaporizer. The collection conditions were as follows: 44mm diameter Cambridge filters were placed in the collector with the rough side facing the incoming vapor. The vaporizer was operated with a suction volume of 55mL, one puff every 30 seconds, each puff lasting 3 seconds, and 20 puffs per sample (2 filters per sample). The two Cambridge filters used to collect the aerosols were placed in a 50mL graduated centrifuge tube, and 20mL of 0.1mol·L⁻¹ centrifuge solution was added. -1 Ammonium acetate solution and 20 μL of mixed internal standard solution were ultrasonically extracted for 40 min, filtered through a 0.22 μm polytetrafluoroethylene filter membrane to obtain the test solution, which was then injected into UPLC-QTOF-MS for analysis to determine the contents of four TSNAs in Examples 1 and 2 and Comparative Examples 1, 2, 3, and 4.

[0050] Table 1. Content determination results (ng·20 puffs) -1 )

[0051] Example 1 0.266 0.073 0.036 0.166 Example 2 0.377 0.111 0.045 0.193 Comparative Example 1 0.544 0.106 0.071 0.258 Comparative Example 2 0.797 0.149 0.121 0.289 Comparative Example 3 0.503 0.100 0.060 0.241 Comparative Example 4 0.547 0.032 0.057 0.082

[0052] As shown in Table 1, when the above-described vaping method was used on six e-cigarette e-liquids, the contents of the four TSNAs in Examples 1 and 2 were significantly lower than those in Comparative Examples 1 and 2. This indicates that after liquid-phase adsorption of TSNAs, the content of the corresponding substances in the e-liquid is significantly reduced, which can effectively reduce the release of harmful substances in the aerosol and significantly mitigate the harm of smoking. Furthermore, we found that the content of the four TSNAs in tobacco extracts prepared from unprocessed tobacco leaves was significantly higher than that in tobacco extracts prepared from flavored tobacco leaves, regardless of whether TSNAs were adsorbed. This may be due to the accumulation of a large amount of harmful substances such as TSNAs during the processing. In Comparative Examples 3 and 4, activated carbon adsorption effectively reduced the content of NNK and NAB in the e-liquid, further demonstrating that liquid-phase adsorption of TSNAs in tobacco extracts can effectively reduce the release of harmful substances in e-cigarette aerosols, thus reducing harm and lowering the risk of cancer for smokers.

[0053] The above descriptions are merely some specific embodiments of the present invention (since the present invention encompasses numerical ranges, the embodiments cannot be exhaustive; the scope of protection described in the present invention includes the numerical range and other technical aspects of the present invention). Specific content or common knowledge known in the solutions is not described in detail here (including but not limited to abbreviations, acronyms, and units conventionally used in the art). It should be noted that the above embodiments do not limit the present invention in any way. For those skilled in the art, all technical solutions obtained by equivalent substitution or equivalent transformation fall within the scope of protection of the present invention. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. An e-cigarette liquid with low TSNA content, characterized in that, The e-cigarette liquid comprises the following components: Tobacco extract, glycerin, propylene glycol, deionized water, nicotine, tobacco flavorings, aroma additives, and antioxidants; The tobacco extract is obtained by extracting burley tobacco shreds, and the raw materials for preparing the tobacco extract include burley tobacco shreds, deionized water, vitamin C, adsorbent, ethyl acetate and alcohol; The adsorbent is H-type mordenite zeolite; The aroma-enhancing additive is prepared by dissolving 500 mg of solanone and 750 mg of megastigmatrienone in 100 mL of alcohol; The method for preparing the e-cigarette liquid with low TSNA content includes the following steps: S1. Weigh out glycerin, propylene glycol and tobacco extract and mix them evenly to prepare a mother liquor; S2. Dissolve nicotine and antioxidant in deionized water, then add to the mother liquor and mix thoroughly to obtain a mixture; S3. Add tobacco flavoring and aroma additives to the mixture, stir evenly, and age for 24 hours to obtain the e-cigarette e-liquid with low TSNA content. The method for preparing the tobacco extract includes: The tobacco leaves are shredded, dried, and then subjected to ultraviolet sterilization. The treated tobacco leaves were added to deionized water containing 12% vitamin C and soaked at 65°C in the dark for 24 hours. The solution was then filtered and separated to obtain filtrate A. H-type mordenite was added to filtrate A at a solid-liquid ratio of 5:1, and stirred in a 30°C water bath in the dark for 1 hour. Then, the supernatant B was obtained by centrifugation. The supernatant B was extracted three times with ethyl acetate to obtain extract C; Extract C was dried under reduced pressure, concentrated, and then dissolved in alcohol to obtain the tobacco extract.

2. The e-cigarette liquid with low TSNA content according to claim 1, characterized in that, The components of the e-cigarette liquid, by weight, include: 30-40 parts glycerin; 30-48 parts of propylene glycol; 5-10 parts deionized water; 2-6 parts of tobacco extract; Nicotine 1-2 parts; 1-4 parts of tobacco flavoring; Flavoring additives: 0.5–1.0 parts; 2-3 parts antioxidant.

3. The e-cigarette liquid with low TSNA content according to claim 2, characterized in that, The components of the e-cigarette liquid, by weight, include: 35-40 parts glycerin; 45-48 parts of propylene glycol; 5-8 parts deionized water; 2-6 parts of tobacco extract; Nicotine 1-2 parts; 1-2 parts of tobacco flavoring; Flavoring additives: 0.5–1.0 parts; Antioxidant 2.5 to 3 parts.

4. The e-cigarette liquid with low TSNA content according to claim 1, characterized in that, The tobacco extract, by weight, comprises: 1-5 parts of Burley tobacco; 10-40 parts deionized water; Vitamin C 1.2–4.8 servings; 5-10 parts of adsorbent; 10-30 parts of ethyl acetate; 1 to 5 parts alcohol.

5. The e-cigarette liquid with low TSNA content according to claim 1, characterized in that, The weight ratio of glycerol to propylene glycol is 1: (1 to 1.2).

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