Efficient and safe plant essential oil mosquito repellent and preparation method thereof

Abstract

The invention discloses an efficient and safe plant essential oil mosquito repellent and a preparation method thereof, and belongs to the field of repellent. The efficient and safe plant essential oil mosquito repellent comprises a core essential oil component, a solvent and an emulsifier, the core essential oil component comprises at least two of mint essential oil, perilla essential oil, lemongrass essential oil, folium artemisiae argyi essential oil, cinnamon essential oil and rhizoma acori graminei essential oil, and the total mass fraction of the core essential oil component is 0.5-2.5% of the total mass of the repellent; the solvent is an ethanol aqueous solution, and the volume fraction of ethanol in the aqueous solution is 5-20%; the mass fraction of the emulsifier is 0.1-5% of the total mass of the composition; the plant-source repellent has the advantages of efficient repelling, safety, environmental protection and controllable process, fills the blank that plant-source repellents in the prior art are difficult to balance the effect and safety, and provides a green alternative scheme for mosquito prevention and control.

Description

Technical Field

[0001] This invention relates to the field of repellent technology, and in particular to a highly efficient and safe plant essential oil mosquito repellent and its preparation method. Background Technology

[0002] Mosquitoes, as widely distributed public health pests, not only infest humans and animals and cause skin inflammation by biting and sucking blood, but also transmit a variety of highly contagious diseases such as malaria, dengue fever, Japanese encephalitis, and lymphatic filariasis, posing a serious threat to human health. This is especially true in tropical and subtropical regions and in hot and humid summer environments, where mosquitoes pose a more prominent threat. Therefore, developing highly effective and safe mosquito repellents is an important requirement for ensuring public health safety and the quality of people's daily lives.

[0003] In the long-term struggle between humans and mosquitoes, chemically synthesized repellents (such as DEET and IR3535) have become mainstream products due to their rapid effectiveness. However, the safety of these chemical agents has always been controversial. Long-term or improper use may irritate human skin and respiratory system, especially posing a significant potential risk to infants and sensitive groups. At the same time, long-term use of chemical repellents alone can easily lead to mosquito resistance, reducing the control effect. Moreover, chemical residues can pollute the ecological environment such as soil and water, which is contrary to the concept of green and environmentally friendly development.

[0004] my country has a long tradition of repelling mosquitoes through plant-based methods such as burning mugwort and wearing sachets, providing a solid practical foundation for the research and development of plant essential oil repellents. Modern research shows that plant essential oils have become a research hotspot in the field of chemical mosquito control due to their advantages such as being green and environmentally friendly, low in toxicity and residue, and not easily causing mosquitoes to develop resistance. To date, more than 500 species of plants with mosquito-repelling and mosquito-killing activities have been discovered worldwide. These plants are mostly concentrated in families such as Lamiaceae, Asteraceae, and Lauraceae. my country has a vast territory and diverse climate, with abundant mosquito-repelling plant resources, providing a sufficient raw material guarantee for the development of plant essential oils.

[0005] However, the research and application of plant essential oil mosquito repellents still face many problems that urgently need to be solved: First, some highly active essential oils have stability defects, such as cinnamon essential oil, which is prone to separation in aqueous solution, affecting the product's effectiveness; second, some essential oils are skin irritants, limiting their application in sensitive populations; third, existing compound formulations are mostly simple mixtures, lacking systematic optimization of component ratios and synergistic mechanisms, resulting in insufficient long-lasting repellency and affecting the product's targeting and applicability. Summary of the Invention

[0006] The purpose of this invention is to solve the problems existing in the prior art by proposing a highly efficient and safe plant essential oil mosquito repellent and its preparation method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A highly effective and safe plant essential oil mosquito repellent includes core essential oil components, solvents, and emulsifiers; The core essential oil components include at least two of peppermint essential oil, perilla essential oil, lemongrass essential oil, mugwort essential oil, cinnamon essential oil, and calamus essential oil, and the total mass fraction of the core essential oil components is 0.5%-2.5% of the total mass of the repellent; The solvent is an aqueous solution of ethanol, and the volume fraction of ethanol in the aqueous solution is 5%-20%. The mass fraction of the emulsifier is 0.1%-5% of the total mass of the composition.

[0008] Preferably, the composition further includes a synergistic ingredient and a cooling and soothing ingredient, wherein the synergistic ingredient is at least one of vitamin E, tea polyphenols, and rosemary extract, and the mass fraction of the synergistic ingredient is 0.05%-2% of the total mass of the composition; and the cooling and soothing ingredient is one of natural menthol and limonene, and the mass fraction of the cooling and soothing ingredient is 0.1%-1% of the total mass of the composition.

[0009] Furthermore, when the core essential oil components include peppermint oil and perilla oil: The volume ratio of peppermint essential oil to perilla essential oil is 1:1, and the total volume of peppermint essential oil and perilla essential oil accounts for 20%-40% of the total volume of the core essential oil components.

[0010] Furthermore, the cinnamon essential oil undergoes a de-irritation treatment, which involves mixing the cinnamon essential oil with anhydrous sodium sulfate and allowing it to stand for 2 to 4 hours, followed by filtration to obtain low-irritation cinnamon essential oil.

[0011] Furthermore, the emulsifier is selected from at least one or more of PEG-40 hydrogenated castor oil, polyglycerol fatty acid esters, Tween 80, and Span 60 to form a compound.

[0012] Furthermore, when the emulsifier is a compound of PEG-40 hydrogenated castor oil and polyglycerol fatty acid ester, the mass ratio of the two is (1-3):1.

[0013] A method for preparing a highly effective and safe plant essential oil mosquito repellent comprises the following steps: Step 1: Weigh the core essential oil components according to the proportions, mix them evenly, and obtain the mixed essential oil; Step 2: Add an aqueous ethanol solution to the mixed essential oils and stir until initially dissolved; Step 3: Then add the emulsifier and stir at 20-30℃ for 10-20 minutes to obtain the premixed solution; Step 4: Perform ultrasonic emulsification on the premixed liquid. The ultrasonic power is 100-300W and the ultrasonic time is 5-15min to obtain a stable emulsion. Step 5: After ultrasonic emulsification in step 4, add the synergistic and cooling / soothing ingredients, and stir for 5-10 minutes until completely dispersed; Step 6: Adjust the pH of the system to 5.5-7.0, let it stand to degas, and then obtain the mosquito repellent.

[0014] Furthermore, the repellency effect of the repellent agent prepared in step six was verified by the following scheme: A. An suction blood-sucking device is used, which is equipped with two parallel blood-sucking units. The surface of the unit is covered with a Parafilm artificial membrane, and constant-temperature pig blood is added under the membrane to simulate human blood. B. Place 300 test mosquitoes into the test chamber of the device. Spray one side of the blood-sucking unit with 1-2 pumps of repellent, 0.1-0.2 ml per pump, as the experimental group. Spray the other side with an equal amount of 5% ethanol aqueous solution as the blank group. C. Starting from the start of spraying, record the number of mosquitoes remaining on the surface of the two artificial films within 2 minutes every 0.5 hours, and continue the test for 3.5 hours. D. Plot the avoidance effect curve of the avoidance agent with time as the horizontal axis and the number of times it lands as the vertical axis.

[0015] Furthermore, the test mosquitoes in step B need to undergo an attack power screening experiment, the specific method of which is as follows: Using the above-mentioned attractive blood-sucking device, without the treatment of repellent in a single blood-sucking unit, if ≥20 out of 300 test mosquitoes remain within 2 minutes and the blood-sucking rate is ≥80%, the attack power is qualified. Unqualified test insects are prohibited from being used in the repellency experiment.

[0016] Furthermore, when the prepared repellent contains peppermint oil and perilla oil: In step two, the volume fraction of ethanol in the ethanol-water solution is limited to 5%, and the volume ratio of the mixed essential oil to the ethanol-water solution is 1:19. In step three, the emulsifier used is PEG-40 hydrogenated castor oil, and the amount of emulsifier added is 1%-1.5% of the total mass of the composition. The stirring temperature is 25-28℃ and the stirring speed is 300-400r / min. In step four, the ultrasonic emulsification power is 200-250W, the ultrasonic time is 8-12min, and the system temperature is controlled to not exceed 30℃ during the ultrasonic process by using an ice-water bath. The particle size of the emulsion after ultrasonication is 100-500nm.

[0017] Compared with the prior art, the present invention provides a highly efficient and safe plant essential oil mosquito repellent and its preparation method, which has the following beneficial effects: 1. The preparation method of this highly efficient and safe plant essential oil mosquito repellent, through the preparation of two core formulas, compound essential oil 1 and compound essential oil 2, and the corresponding ultrasonic emulsification preparation process, solves the problems of slow onset and insufficient long-term effect of existing plant essential oil repellents. Compound essential oil 1 can achieve rapid onset of effect in 0.5 hours, and compound essential oil 2 can achieve stable repellency in 3 hours, with a repellency rate of ≥92% for both, and is effective against mosquito species that transmit mainstream diseases. Secondly, by de-irritating cinnamon essential oil and simplifying the composition of compound essential oil 2, low irritation and high compatibility are achieved, covering both the general population and sensitive populations. The optimized ultrasonic emulsification parameters and emulsifier compounding scheme solve the instability defects of single essential oils, making it suitable for laboratory preparation and industrial mass production.

[0018] The parts of this device not covered herein are the same as or can be implemented using existing technologies. This invention can balance high efficiency, safety and environmental protection, and controllable process, filling the gap in the existing technology where plant-derived repellents are difficult to balance efficacy and safety, and providing a green alternative for mosquito control. Attached Figure Description

[0019] Figure 1 A schematic diagram illustrating the changing trend of lemongrass essential oil; Figure 2 A schematic diagram illustrating the changing trend of Artemisia argyi essential oil; Figure 3 This is a schematic diagram illustrating the changing trends of peppermint essential oil. Figure 4 This is a schematic diagram illustrating the changing trend of perilla essential oil. Figure 5 A schematic diagram illustrating the changing trends of patchouli essential oil; Figure 6 This is a schematic diagram illustrating the changing trends of cinnamon essential oil. Figure 7 A schematic diagram illustrating the changing trend of Acorus calamus essential oil; Figure 8 This is a schematic diagram illustrating the changing trends of eucalyptus essential oil. Figure 9 This is a schematic diagram illustrating the changing trend of ginger essential oil. Figure 10 This is a schematic diagram illustrating the changing trend of catnip essential oil. Figure 11 A schematic diagram illustrating the changing trend of Cyperus rotundus essential oil; Figure 12 A schematic diagram illustrating the changing trend of camphor wood essential oil; Figure 13 This is a schematic diagram illustrating the changing trend of clove essential oil. Figure 14 A schematic diagram showing the changing trend of 15% DEET; Figure 15 A schematic diagram illustrating the changing trends of plant-based mosquito repellents; Figure 16 This is a schematic diagram illustrating the changing trends of the blank control group; Figure 17 A diagram summarizing the repellent effects of plant essential oils; Figure 18 This is a schematic diagram illustrating the changing trend of compound essential oil 1; Figure 19 This is a schematic diagram illustrating the changing trend of compound essential oil 2. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0022] Reference Figure 1 - As shown in the figure, in order to address the shortcomings of the prior art, this application first focuses on the core needs of natural, efficient, and low-irritation products, and conducts a large-scale mosquito repellency screening experiment on single plant essential oils. No synergistic ingredients, cooling and soothing ingredients, or compound adjuvants were added during the experiment. Only single plant essential oils were used as test objects, and a unified experimental standard was adopted (referring to GB / T13917.9-2009 "Indoor Efficacy Test and Evaluation of Sanitary Insecticides for Pesticide Registration - Part 9 Repellents") to systematically detect the repellency activity of different plant essential oils against target mosquito species.

[0023] The specific screening experiment was conducted as follows: More than 20 kinds of plant essential oils from Lamiaceae, Asteraceae, Lauraceae, and other families that have been reported to have mosquito-repellent potential were selected, including lemongrass essential oil, artemisia essential oil, cinnamon essential oil, calamus essential oil, peppermint essential oil, perilla essential oil, eucalyptus essential oil, ginger essential oil, and catnip essential oil. Each essential oil was prepared into a single-ingredient test solution according to the ratio of "0.5ml essential oil + 0.5ml ethanol + 19ml water", without the addition of emulsifiers or other substances. Qualified test insects and test models were screened through an attack power experiment. The repellency effect of each single essential oil was dynamically monitored for 3.5 hours, and the number of times mosquitoes landed at each time point was recorded. The repellency rate was calculated, and the repellency effect curve was plotted. The test model used an attractive blood-sucking device, and Parafilm artificial membrane combined with constant-temperature pig blood was used to simulate human skin.

[0024] Reference Figure 1 Regarding lemongrass essential oil, the experimental data are as follows:

[0025] To ensure the scientific validity and reliability of the screening results and avoid misjudgments due to accidental fluctuations in the experiments, this application uses one-way ANOVA to statistically verify the repulsion test data for all single essential oils, as detailed below:

[0026] The content in the abstract is a visual substitute for the adjusted P-value: “ "This indicates that the adjusted P-value is <0.001, which is Level 1, proving that the difference is extremely significant. Specifically, it shows that more than 99.9% of the change in the number of mosquito landings at this time point is due to the repellent effect of the essential oil. Random fluctuations, such as the probability of random changes in mosquito activity, are less than 0.1%, demonstrating the extremely high stability and reliability of the repellent effect." "This represents a p-value of 0.001 ≤ P < 0.01, which is the second level, indicating a highly significant difference. Specifically, it means that over 99% of the change in the number of mosquito landings at this time point is due to the repellent effect of the essential oil, with the probability of occasional fluctuations between 0.1% and 1%, demonstrating a high degree of stability in the repellent effect." "0.01 ≤ P < 0.05" represents the third level, indicating a significant difference. Specifically, it means that more than 95% of the change in the number of mosquito landings at this time point is due to the repellency effect of the essential oil, with the probability of random fluctuations between 1% and 5%. The repellency effect has statistical reliability. "ns" represents the fourth level, indicating a non-significant difference. Specifically, it means that the change in the number of mosquito landings at this time point is mainly due to random fluctuations in the experiment, and it cannot be confirmed that it is due to the repellency effect of the essential oil.

[0027] Reference Figure 2 Regarding mugwort essential oil, the experimental data are as follows:

[0028] The one-way ANOVA is detailed below:

[0029] The content of the abstract is the same as described above.

[0030] Reference Figure 3 Regarding peppermint essential oil, the experimental data are as follows:

[0031] The one-way ANOVA is detailed below:

[0032] The content of the abstract is the same as described above.

[0033] Reference Figure 4 Regarding perilla essential oil, the experimental data are as follows:

[0034] The one-way ANOVA is detailed below:

[0035] The content of the abstract is the same as described above.

[0036] Reference Figure 5 The experimental data for patchouli essential oil are as follows:

[0037] The one-way ANOVA is detailed below:

[0038] The content of the abstract is the same as described above.

[0039] Reference Figure 6 Regarding cinnamon essential oil, the experimental data are as follows:

[0040] The one-way ANOVA is detailed below:

[0041] The content of the abstract is the same as described above.

[0042] Reference Figure 7 The experimental data for Acorus calamus essential oil are as follows:

[0043] The details of the one-way ANOVA are as follows:

[0044] The content of the abstract is the same as described above.

[0045] Reference Figure 8 Regarding eucalyptus essential oil, the experimental data are as follows:

[0046] The one-way ANOVA is detailed below:

[0047] The content of the abstract is the same as described above.

[0048] Reference Figure 9Regarding ginger essential oil, the experimental data are as follows:

[0049] The one-way ANOVA is detailed below:

[0050] The content of the abstract is the same as described above.

[0051] Reference Figure 10 The experimental data for catnip essential oil are as follows:

[0052] The one-way ANOVA is detailed below:

[0053] The content of the abstract is the same as described above.

[0054] Reference Figure 11 The experimental data for Cyperus rotundus essential oil are as follows:

[0055] The one-way ANOVA is detailed below:

[0056] The content of the abstract is the same as described above.

[0057] Reference Figure 12 Regarding camphor wood essential oil, the experimental data are as follows:

[0058] The one-way ANOVA is detailed below:

[0059] The content of the abstract is the same as described above.

[0060] Reference Figure 13 Regarding clove essential oil, the experimental data are as follows:

[0061] The one-way ANOVA is detailed below:

[0062] The content of the abstract is the same as described above.

[0063] Reference Figures 14-15 Based on the aforementioned single essential oil, this application also includes two positive control groups. Positive control group 1 uses 15% DEET, and the specific experimental data are as follows:

[0064] The one-way ANOVA is as follows:

[0065] Positive control group 2 used commercially available plant-based mosquito repellent. Specific experimental data are as follows:

[0066] The one-way ANOVA is detailed below:

[0067] The content of the abstracts in positive control group 1 and positive control group 2 is the same as described above.

[0068] Reference Figure 16 A blank control group was set up synchronously. The experimental data of the blank control group are as follows:

[0069] The one-way ANOVA is detailed below:

[0070] The content of the abstract is the same as described above.

[0071] Reference Figure 17 Based on the above experimental results, it was found that the repellent effects of several essential oils, including lemongrass, mugwort, cinnamon, and calamus, were significant. The results of comparing these essential oils with the blank group and the control group are as follows:

[0072] Through extensive statistical analysis of experimental data, the inventors discovered that while most single essential oils possess a certain repellency effect, they have significant limitations. For example, the repellency rates of eucalyptus oil, ginger oil, and camphor oil are only maintained at 60%-75%, and their effects rapidly diminish after 2 hours. In contrast, six essential oils—citronella oil, mugwort oil, cinnamon oil, calamus oil, peppermint oil, and perilla oil—exhibit significant repellency advantages: their average repellency rate within 3.5 hours is ≥85%. Among them, lemongrass oil and cinnamon oil achieve peak repellency rates of over 92% against Aedes albopictus, while calamus oil and mugwort oil demonstrate outstanding long-lasting repellency, maintaining a repellency rate of ≥88% after 3 hours. Peppermint oil and perilla oil, on the other hand, take effect quickly, achieving a repellency rate of 90% within 0.5 hours.

[0073] Further research revealed that the active ingredients of these six superior essential oils are concentrated in terpenes, alcohols, ketones, and other substances, and their mechanisms of action are complementary—the volatile components of lemongrass and cinnamon essential oils can quickly form a spatial barrier, peppermint and perilla essential oils can enhance the inhibitory effect on mosquitoes' sense of smell, and artemisia and calamus essential oils can prolong the repellency effect. However, there are still problems to be solved when using them alone: ​​cinnamon essential oil is prone to separation in aqueous solution, affecting its effectiveness; although the repellency rate of a single essential oil is higher than that of other plant essential oils, there is still room for improvement compared to commercially available chemical repellents; some essential oils have mild skin irritation, such as cinnamon essential oil, which limits the applicable population.

[0074] Based on the findings of the above single-component screening experiments, the core repellency value of the six essential oils was clarified, and the shortcomings of using them individually were identified. The technical solution of this invention is proposed: using these six essential oils as core components, a synergistic effect is achieved through scientific compounding. At the same time, the solvent ratio is optimized, suitable emulsifiers are screened, and the preparation process is improved to solve the problems of stability and irritation, ultimately forming a highly efficient, safe, and long-lasting plant essential oil mosquito repellent.

[0075] Example 1: Refer to Figures 1-19 This application discloses a highly efficient and safe plant essential oil mosquito repellent, comprising a core essential oil component, a solvent, and an emulsifier; The core essential oil components include peppermint essential oil, perilla essential oil, lemongrass essential oil, mugwort essential oil, and cinnamon essential oil, and the total mass fraction of the core essential oil components is 0.5%-2.5% of the total mass of the repellent. The solvent is an aqueous solution of ethanol, and the volume fraction of ethanol in the aqueous solution is 5%-20%. The mass fraction of the emulsifier is 0.1%-5% of the total mass of the composition.

[0076] It also includes synergistic and cooling soothing ingredients. The synergistic ingredient is at least one of vitamin E, tea polyphenols, and rosemary extract. In this embodiment, a mixture of vitamin E and tea polyphenols is selected. The mass fraction of the synergistic ingredient is 0.05%-2% of the total mass of the composition. The cooling soothing ingredient is one of natural menthol and limonene. In this embodiment, natural menthol is selected. The mass fraction of the cooling soothing ingredient is 0.1%-1% of the total mass of the composition.

[0077] The volume ratio of peppermint essential oil to perilla essential oil is 1:1, and the total volume of peppermint essential oil and perilla essential oil accounts for 20%-40% of the total volume of the core essential oil components.

[0078] The cinnamon essential oil undergoes a de-irritation treatment, which involves mixing cinnamon essential oil with anhydrous sodium sulfate and allowing it to stand for 2 to 4 hours, followed by filtration to obtain low-irritation cinnamon essential oil.

[0079] The emulsifier is selected from at least one or more of PEG-40 hydrogenated castor oil, polyglycerol fatty acid ester, Tween 80, and Span 60 to form a compound. In this embodiment, a compound formed by mixing PEG-40 hydrogenated castor oil and polyglycerol fatty acid ester is selected; the mass ratio of the two is (1-3):1.

[0080] In this embodiment, a method for preparing a highly efficient and safe plant essential oil mosquito repellent involves the following steps: Step 1: Weigh the core essential oil components according to the proportions, mix them evenly, and obtain the mixed essential oil; In this step, take 5 drops of lemongrass essential oil, 5 drops of mugwort essential oil, 5 drops of peppermint essential oil, 5 drops of perilla essential oil, and 2 drops of cinnamon essential oil, totaling about 1 ml.

[0081] Step 2: Add an ethanol-water solution to the mixed essential oils and stir until initially dissolved. Specifically, add 1 ml of ethanol and then 18 ml of water. Step 3: Then add the emulsifier and stir at 20°C for 20 minutes to obtain the premixed solution; Step 4: The premixed liquid is subjected to ultrasonic emulsification treatment with an ultrasonic power of 200W and an ultrasonic time of 10min to obtain a stable emulsion. Step 5: After ultrasonic emulsification in step 4, add the synergistic and cooling / soothing ingredients, and stir for 8 minutes until completely dispersed; Step 6: Adjust the pH of the system to 5.5-7.0, let it stand to degas, and then obtain the mosquito repellent.

[0082] The repellency effect of the repellent prepared in step six was verified by the following scheme: A. An suction blood-sucking device is used, which is equipped with two parallel blood-sucking units. The surface of the unit is covered with a Parafilm artificial membrane, and constant-temperature pig blood is added under the membrane to simulate human blood. B. Place 300 test mosquitoes into the test chamber of the device. Spray the repellent agent 1-2 times on one side of the blood-sucking unit, 0.1-0.2 ml per pump, as the experimental group. Spray an equal amount of 5% ethanol aqueous solution on the other side as the blank group. C. Starting from the start of spraying, record the number of mosquitoes remaining on the surface of the two artificial films within 2 minutes every 0.5 hours, and continue the test for 3.5 hours. D. Plot the avoidance effect curve of the avoidance agent with time as the horizontal axis and the number of times it lands as the vertical axis.

[0083] The test mosquitoes in step B need to undergo an attack power screening test. The specific method is as follows: Using the above-mentioned attractive blood-sucking device, without the treatment of repellent in a single blood-sucking unit, if ≥20 out of 300 test mosquitoes remain within 2 minutes and the blood-sucking rate is ≥80%, the attack power is qualified. Unqualified test insects are prohibited from being used in the repellency experiment.

[0084] When the prepared repellent contains peppermint oil and perilla oil: In step two, the volume fraction of ethanol in the ethanol-water solution is limited to 5%, and the volume ratio of the mixed essential oil to the ethanol-water solution is 1:19. In step three, the emulsifier used is PEG-40 hydrogenated castor oil, and the amount of emulsifier added is 1%-1.5% of the total mass of the composition. The stirring temperature is 25-28℃ and the stirring speed is 300-400r / min. In step four, the ultrasonic emulsification power is 200-250W, the ultrasonic time is 8-12min, and the system temperature is controlled to not exceed 30℃ during the ultrasonic process by using an ice-water bath. The particle size of the emulsion after ultrasonication is 100-500nm.

[0085] Based on the above preparation method, compound essential oil 1 was prepared, and the experimental data of compound essential oil 1 are as follows:

[0086] The one-way ANOVA is detailed below:

[0087] Example 2: Refer to Figures 1-19 This application discloses a highly efficient and safe plant essential oil mosquito repellent, comprising a core essential oil component, a solvent, and an emulsifier; The core essential oil components include peppermint essential oil, perilla essential oil, mugwort essential oil, and calamus essential oil, and the total mass fraction of the core essential oil components is 0.5%-2.5% of the total mass of the repellent. The solvent is an aqueous solution of ethanol, and the volume fraction of ethanol in the aqueous solution is 5%-20%. The mass fraction of the emulsifier is 0.1%-5% of the total mass of the composition.

[0088] It also includes synergistic and cooling soothing ingredients. The synergistic ingredient is at least one of vitamin E, tea polyphenols, and rosemary extract. In this embodiment, a mixture of vitamin E and tea polyphenols is selected. The mass fraction of the synergistic ingredient is 0.05%-2% of the total mass of the composition. The cooling soothing ingredient is one of natural menthol and limonene. In this embodiment, natural menthol is selected. The mass fraction of the cooling soothing ingredient is 0.1%-1% of the total mass of the composition.

[0089] The volume ratio of peppermint essential oil to perilla essential oil is 1:1, and the total volume of peppermint essential oil and perilla essential oil accounts for 20%-40% of the total volume of the core essential oil components.

[0090] The emulsifier is selected from at least one or more of PEG-40 hydrogenated castor oil, polyglycerol fatty acid ester, Tween 80, and Span 60 to form a compound. In this embodiment, a compound formed by mixing PEG-40 hydrogenated castor oil and polyglycerol fatty acid ester is selected; the mass ratio of the two is (1-3):1.

[0091] In this embodiment, a method for preparing a highly efficient and safe plant essential oil mosquito repellent involves the following steps: Step 1: Weigh the core essential oil components according to the proportions, mix them evenly, and obtain the mixed essential oil; In this step, take 10 drops of mugwort essential oil, 5 drops of peppermint essential oil, 5 drops of perilla essential oil, and 10 drops of calamus essential oil.

[0092] Step 2: Add an ethanol-water solution to the mixed essential oils and stir until initially dissolved. Specifically, add 1 ml of ethanol and then 18 ml of water. Step 3: Then add the emulsifier and stir at 30°C for 20 minutes to obtain the premixed solution; Step 4: The premixed liquid is subjected to ultrasonic emulsification treatment with an ultrasonic power of 200W and an ultrasonic time of 15min to obtain a stable emulsion. Step 5: After ultrasonic emulsification in step 4, add the synergistic and cooling / soothing ingredients, and stir for 10 minutes until completely dispersed; Step 6: Adjust the pH of the system to 5.5-7.0, let it stand to degas, and then obtain the mosquito repellent.

[0093] The repellency effect of the repellent prepared in step six was verified by the following scheme: A. An suction blood-sucking device is used, which is equipped with two parallel blood-sucking units. The surface of the unit is covered with a Parafilm artificial membrane, and constant-temperature pig blood is added under the membrane to simulate human blood. B. Place 300 test mosquitoes into the test chamber of the device. Spray one side of the blood-sucking unit with 1-2 pumps of repellent, 0.1-0.2 ml per pump, as the experimental group. Spray the other side with an equal amount of 5% ethanol aqueous solution as the blank group. C. Starting from the start of spraying, record the number of mosquitoes remaining on the surface of the two artificial films within 2 minutes every 0.5 hours, and continue the test for 3.5 hours. D. Plot the avoidance effect curve of the avoidance agent with time as the horizontal axis and the number of times it lands as the vertical axis.

[0094] The test mosquitoes in step B need to undergo an attack power screening test. The specific method is as follows: Using the above-mentioned attractive blood-sucking device, without the treatment of repellent in a single blood-sucking unit, if ≥20 out of 300 test mosquitoes remain within 2 minutes and the blood-sucking rate is ≥80%, the attack power is qualified. Unqualified test insects are prohibited from being used in the repellency experiment.

[0095] Based on the above preparation method, compound essential oil 2 was prepared, and the experimental data of compound essential oil 2 are as follows:

[0096] The one-way ANOVA is detailed below:

[0097] The abstracts for Compound Essential Oil 1 and Compound Essential Oil 2 contain the same information as described above.

[0098] In summary, the two core formulations, Compound Essential Oil 1 and Compound Essential Oil 2, prepared in this application, along with the corresponding ultrasonic emulsification preparation process, solve the problems of slow onset and insufficient long-term effectiveness of existing plant essential oil repellents. Compound Essential Oil 1 can achieve rapid onset of action within 0.5 hours, while Compound Essential Oil 2 can achieve stable repellency within 3 hours, with repellency rates of ≥92% for both, and are effective against mosquito species that transmit mainstream diseases. Secondly, by de-irritating cinnamon essential oil and simplifying the composition of Compound Essential Oil 2, low irritation and high compatibility are achieved, covering both the general population and sensitive populations. The optimized ultrasonic emulsification parameters and emulsifier compounding scheme solve the stability defects of single essential oils, making them suitable for laboratory preparation and industrial mass production.

[0099] In summary, the compound essential oil and its preparation method provided by this invention take into account high efficiency, safety and environmental protection, and controllable process, filling the gap in the existing technology where plant-derived repellents are difficult to balance efficacy and safety, and providing a green alternative for mosquito control.

[0100] In practical use, Compound Essential Oil 1 can be made into a portable spray for immediate protection in outdoor camping, park activities, and areas with high mosquito density. It utilizes its 0.5-hour rapid onset of action to quickly establish a mosquito barrier. Compound Essential Oil 2 can be made into an indoor slow-release agent for use in bedrooms, offices, children's rooms, and other spaces where people spend a lot of time. It relies on its 3-hour stable repellency ability to reduce the need for frequent re-spraying.

[0101] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A highly effective and safe plant essential oil mosquito repellent, characterized in that, Including core essential oil components, solvents, and emulsifiers; The core essential oil components include at least two of peppermint essential oil, perilla essential oil, lemongrass essential oil, mugwort essential oil, cinnamon essential oil, and calamus essential oil, and the total mass fraction of the core essential oil components is 0.5%-2.5% of the total mass of the repellent; The solvent is an aqueous solution of ethanol, and the volume fraction of ethanol in the aqueous solution is 5%-20%. The mass fraction of the emulsifier is 0.1%-5% of the total mass of the composition.

2. The highly efficient and safe plant essential oil mosquito repellent according to claim 1, characterized in that, It also includes synergistic and cooling soothing ingredients. The synergistic ingredient is at least one of vitamin E, tea polyphenols, and rosemary extract, and the mass fraction of the synergistic ingredient is 0.05%-2% of the total mass of the composition. The cooling soothing ingredient is one of natural menthol and limonene, and the mass fraction of the cooling soothing ingredient is 0.1%-1% of the total mass of the composition.

3. The highly efficient and safe plant essential oil mosquito repellent according to claim 2, characterized in that, When the core essential oil components include peppermint oil and perilla oil: The volume ratio of peppermint essential oil to perilla essential oil is 1:1, and the total volume of peppermint essential oil and perilla essential oil accounts for 20%-40% of the total volume of the core essential oil components.

4. The highly efficient and safe plant essential oil mosquito repellent according to claim 3, characterized in that, The cinnamon essential oil undergoes a de-irritation treatment, which involves mixing cinnamon essential oil with anhydrous sodium sulfate and allowing it to stand for 2 to 4 hours, followed by filtration to obtain low-irritation cinnamon essential oil.

5. The highly efficient and safe plant essential oil mosquito repellent according to claim 4, characterized in that, The emulsifier is selected from at least one or more of PEG-40 hydrogenated castor oil, polyglycerol fatty acid esters, Tween 80, and Span 60 to form a compound.

6. The highly efficient and safe plant essential oil mosquito repellent according to claim 5, characterized in that, When the emulsifier is a compound of PEG-40 hydrogenated castor oil and polyglycerol fatty acid ester, the mass ratio of the two is (1-3):

1.

7. A method for preparing a highly efficient and safe plant essential oil mosquito repellent as described in any one of claims 2-6, characterized in that, Follow these steps: Step 1: Weigh the core essential oil components according to the proportions, mix them evenly, and obtain the mixed essential oil; Step 2: Add an aqueous ethanol solution to the mixed essential oils and stir until initially dissolved; Step 3: Then add the emulsifier and stir at 20-30℃ for 10-20 minutes to obtain the premixed solution; Step 4: Perform ultrasonic emulsification on the premixed liquid. The ultrasonic power is 100-300W and the ultrasonic time is 5-15min to obtain a stable emulsion. Step 5: After ultrasonic emulsification in step 4, add the synergistic and cooling / soothing ingredients, and stir for 5-10 minutes until completely dispersed; Step 6: Adjust the pH of the system to 5.5-7.0, let it stand to degas, and then obtain the mosquito repellent.

8. The preparation method of a highly efficient and safe plant essential oil mosquito repellent according to claim 7, characterized in that, The repellency effect of the repellent prepared in step six was verified by the following scheme: A. An suction blood-sucking device is used, which is equipped with two parallel blood-sucking units. The surface of the unit is covered with a Parafilm artificial membrane, and constant-temperature pig blood is added under the membrane to simulate human blood. B. Place 300 test mosquitoes into the test chamber of the device. Spray one side of the blood-sucking unit with 1-2 pumps of repellent, 0.1-0.2 ml per pump, as the experimental group. Spray the other side with an equal amount of 5% ethanol aqueous solution as the blank group. C. Starting from the start of spraying, record the number of mosquitoes remaining on the surface of the two artificial films within 2 minutes every 0.5 hours, and continue the test for 3.5 hours. D. Plot the avoidance effect curve of the avoidance agent with time as the horizontal axis and the number of times it lands as the vertical axis.

9. The preparation method of a highly efficient and safe plant essential oil mosquito repellent according to claim 8, characterized in that, The test mosquitoes in step B need to undergo an attack power screening test. The specific method is as follows: Using the above-mentioned attractive blood-sucking device, without the treatment of repellent in a single blood-sucking unit, if ≥20 out of 300 test mosquitoes remain within 2 minutes and the blood-sucking rate is ≥80%, the attack power is qualified. Unqualified test insects are prohibited from being used in the repellency experiment.

10. The highly efficient and safe plant essential oil mosquito repellent and its preparation method according to claim 7, characterized in that, When the prepared repellent contains peppermint oil and perilla oil: In step two, the volume fraction of ethanol in the ethanol-water solution is limited to 5%, and the volume ratio of the mixed essential oil to the ethanol-water solution is 1:

19. In step three, the emulsifier used is PEG-40 hydrogenated castor oil, and the amount of emulsifier added is 1%-1.5% of the total mass of the composition. The stirring temperature is 25-28℃ and the stirring speed is 300-400r / min. In step four, the ultrasonic emulsification power is 200-250W, the ultrasonic time is 8-12min, and the system temperature is controlled to not exceed 30℃ during the ultrasonic process by using an ice-water bath. The particle size of the emulsion after ultrasonication is 100-500nm.

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