A slow-release mosquito attractant and its use

Abstract

This invention relates to the field of mosquito attraction technology, and particularly to a slow-release mosquito attractant and its application. The slow-release attractant comprises an active ingredient and a composite porous carrier. The active ingredient comprises the following components in parts by weight: 500-550 parts octanol, 280-350 parts lactic acid, 0.1-0.15 parts nonanal, and 0.1-0.15 parts urea. The active ingredient is uniformly adsorbed into the pores of the composite porous carrier through a loading process. This solution, by employing a specific ratio of active ingredients, forms a synergistic effect, significantly enhancing the attraction to mosquitoes. Octanol and lactic acid provide a scent background similar to human sweat, while nonanal further triggers the chemotactic behavior of mosquitoes. Urea helps regulate the solubility and stability of the mixture. This not only improves the initial attraction rate but also maintains the long-term attraction effect through the interaction between components, avoiding the adaptive decline problem that may occur with a single component, thus maintaining stable attraction performance even in complex environments.

Description

Technical Field

[0001] This invention relates to the field of mosquito attraction technology, and in particular to a slow-release mosquito attractant and its application. Background Technology

[0002] Mosquitoes are important vectors of disease transmission, and their effective control has always been a core issue in public health and household protection. Mosquito attractants play a crucial role in monitoring, trapping, and integrated pest management by mimicking human or animal body odor to attract target mosquito species. Current mosquito attractants are mostly formulated with chemical components, aiming to attract mosquitoes through odor signals. However, they generally suffer from problems such as single-component formulations, uncontrollable release, and insufficient persistence, limiting their practical application effectiveness.

[0003] While existing attractants may exhibit some attraction effects in the short term, their rapid release rate and short duration of action often necessitate frequent replacement or replenishment, increasing usage costs and management burden. Furthermore, the rapid volatilization of attractant components can lead to a sharp drop in concentration, significantly weakening long-term attraction effects and failing to meet the needs of sustained pest control. Simultaneously, the insufficient adsorption performance and stability of the carrier material further affect the sustained-release performance and reliability of the attractant. To address these shortcomings, this invention proposes a mosquito sustained-release attractant and its application. By optimizing the active ingredient ratio and combining it with a high-performance carrier, the controlled release and long-lasting effect of the attractant are achieved. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a slow-release mosquito attractant and its application, thereby solving the technical problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A mosquito slow-release attractant includes an active ingredient and a composite porous carrier. The active ingredient comprises the following components in parts by weight: 500-550 parts octanol, 280-350 parts lactic acid, 0.1-0.15 parts nonanal, and 0.1-0.15 parts urea. The active ingredient is uniformly adsorbed into the pores of the composite porous carrier through a loading process.

[0006] In one possible implementation, the composite porous support is prepared by the following method: (a) Raw material mixing: Polyurethane particles with a particle size of 50-80μm, nano-hydroxyapatite with a particle size of 30-50nm, and polyvinylpyrrolidone with a molecular weight of 50,000-60,000 are mixed at a mass ratio of 15:2:1 at 60-80℃ and a rotation speed of 600-900r / min for 20-40 minutes. (b) Pore control: Add deionized water and citric acid to the mixed substrate, adjust the pH of the system to 5.0-6.0, stir to form a uniform slurry and then inject it into the mold; (c) Crosslinking and curing: Place the mold in an environment of 55-65℃ and keep it warm for 1.5-2.5 hours to allow the polyvinylpyrrolidone molecular chains to undergo a crosslinking reaction with the polyurethane particles; (d) Surface modification: Immerse the cured carrier in a 5%-10% glycerol aqueous solution and keep it at a constant temperature of 45-55℃ for 1-2 hours; (e) Drying and shaping: After rinsing the surface-modified carrier, freeze-dry it for 10-14 hours at -40℃ and vacuum degree below 10Pa to obtain a composite porous carrier with a porosity of 70%-80%, a saturated adsorption capacity of 240%-260% of its own mass, and a compression resilience greater than 90%.

[0007] In one possible implementation, the load process includes the following steps: S1: Mix octanol, lactic acid, nonanal, and urea according to the specified ratio, and bring the volume to 1000 mL to form an attractant mixture, wherein the concentration of octanol is 500-550 mg / mL, the concentration of lactic acid is 280-350 mg / mL, the concentration of nonanal is 0.1-0.15 mg / mL, and the concentration of urea is 0.1-0.15 mg / mL; S2: The composite porous carrier is ultrasonically cleaned and then dried at 65-70℃ to constant weight. S3: Place the dried composite porous carrier in a vacuum environment and maintain it for 30-35 minutes under a vacuum degree not lower than -0.095 MPa; S4: Under vacuum, inject the attractant mixture into the composite porous carrier, then restore normal pressure and soak for 3-5 hours, shaking the container intermittently during the process; S5: Remove the loaded composite porous carrier, absorb the residual liquid on the surface, and let it stand for 16-20 hours under ventilation until the concentration of surface volatiles is lower than 0.1 mg / m³, to obtain the mosquito slow-release attractant.

[0008] In one possible implementation, in step S2, the ultrasonic cleaning power is 300-350W and the cleaning time is 8-10 minutes.

[0009] In one possible implementation, in step S3, the degassing is maintained for 30-35 minutes under a vacuum of not less than -0.095 MPa.

[0010] In one possible implementation, in step S4, the attractant loading of each composite porous carrier is 80%-85% of its saturated adsorption capacity.

[0011] In one possible implementation, the composite porous carrier is a circular sheet structure with a single sheet mass of 0.39-0.41 g.

[0012] In one possible implementation, the composite porous carrier, after loading the attractant, has a single-piece mass of 1.17-1.22 g.

[0013] In one possible implementation, the mosquito slow-release attractant is used to trap Culex pipiens quinquefolius and / or Aedes albopictus.

[0014] Beneficial effects compared to existing technologies: 1. In this formulation, a specific ratio of active ingredients, including octanol, lactic acid, nonanal, and urea, is used to create a synergistic effect, significantly enhancing the attraction to mosquitoes. These ingredients mimic the olfactory signals that mosquitoes rely on when searching for hosts in their natural environment. Octanol and lactic acid serve as basic attractants, providing a background odor similar to human sweat, while nonanal acts as a key signaling molecule, further triggering chemotaxis in mosquitoes. The addition of urea helps regulate the solubility and stability of the mixture, ensuring uniform dispersion of each component and maintaining its activity. By controlling the concentration of each component, the attractant can effectively target multiple mosquito species, improving the breadth and efficiency of attraction. It not only increases the initial attraction rate but also maintains long-term attraction through the interaction between components, avoiding the adaptive degradation that may occur with a single component, thus maintaining stable attraction performance even in complex environments. 2. In this solution, the attractant is loaded onto a composite porous carrier and surface modification technology is used to achieve controlled, sustained release of the attractant. The composite porous carrier uses polyurethane particles as the substrate, combined with nano-hydroxyapatite and polyvinylpyrrolidone. Through pore control, it forms a high specific surface area and interconnected pore structure, which can fully adsorb the attractant mixture. After surface modification with glycerol, the carrier's surface properties are optimized, enhancing its interaction with the attractant components and effectively slowing the release rate. This sustained-release mechanism ensures that the attractant slowly seeps out of the carrier, maintaining a stable concentration in the environment and avoiding a sharp drop in effectiveness due to rapid volatilization. By adjusting the adsorption capacity and release curve of the carrier, the attractant can continue to function for a longer period, reducing replacement frequency and maintenance costs. This makes it suitable for long-term mosquito monitoring and control scenarios, improving practicality and economy. 3. In this scheme, the preparation process of the composite porous carrier, including raw material mixing, pore control, cross-linking curing, surface modification, and drying and shaping, ensures the physical stability and structural consistency of the carrier. During the preparation process, the mechanical strength of the carrier is enhanced through cross-linking reaction, enabling the carrier to maintain morphological stability under external pressure and exhibiting high compression resilience. Pore control optimizes the pore size distribution, forming uniform interconnected pores, which is beneficial for the uniform adsorption and release of the attractant. Surface modification, through glycerol treatment, not only delays release but also improves the carrier's resistance to environmental changes. Drying and shaping employs vacuum freeze-drying to preserve the pore structure and prevent collapse. The combination of these processes ensures that the carrier maintains stable performance during long-term storage and use, ensuring that the attractant is not affected by external conditions, thereby providing a reliable long-lasting attractant effect and enhancing the product's durability and applicability. Attached Figure Description

[0015] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the mosquito slow-release attractant preparation method of the present invention; Figure 2 This is a schematic diagram of the process for preparing the composite porous carrier of the present invention. Detailed Implementation

[0017] Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention can also be implemented in various different forms, and therefore the present invention is not limited to the embodiments described below. In addition, for the purpose of more clearly describing the present invention, parts not connected to the invention will be omitted from the drawings. The technical solutions in this application are designed to address the problems described in the background, and are generally as follows: Please refer to Figure 1 , Figure 2 This invention introduces a mosquito slow-release attractant, which is composed of a specific ratio of active ingredients and a composite porous carrier. The composite porous carrier possesses high adsorption capacity and controllable slow-release performance, effectively prolonging the attractant's action time. The preparation of the composite porous carrier, the formulation of the attractant, and performance testing are described in detail below: I. Preparation of composite porous carriers The preparation process of the composite porous carrier includes five steps: raw material mixing, pore control, cross-linking and curing, surface modification, and drying and shaping, as detailed below: 1. Raw material preparation: Substrate: Medical-grade polyurethane particles (particle size 50-80µm), density (0.32g / cm³). 3Elastic modulus (1.2 MPa), nano-hydroxyapatite (particle size 30-50 nm, specific surface area 180 m²) 2 / g), polyvinylpyrrolidone (molecular weight 58000, K value 30).

[0018] Auxiliary reagents: deionized water, glycerol (analytical grade), citric acid (99% purity).

[0019] Dosage ratio: To prepare 1000g of composite porous carrier each time, you need 750g of polyurethane particles, 100g of nano hydroxyapatite, 50g of polyvinylpyrrolidone, 50g of glycerol, 50g of citric acid, and a total amount of deionized water of 3000mL.

[0020] 2. Preparation steps: Substrate mixing: 750g of polyurethane particles, 100g of nano-hydroxyapatite, and 50g of polyvinylpyrrolidone were added to a twin-screw mixer. The mixer was set to a speed of 800 rpm and a temperature of 70℃, and mixed for 30 minutes. During the process, the hydroxyl groups on the surface of the nano-hydroxyapatite formed coordination bonds with the amino groups of the polyurethane particles, uniformly coating the polyurethane surface to form a core-shell structure. Dynamic light scattering analysis showed that the Zeta potential of the composite particles changed from −15mV to −25mV, indicating a significant improvement in dispersion stability.

[0021] Pore ​​control: Add 2000 mL of deionized water to the mixed composite particles, reduce the stirring speed to 500 r / min, and slowly add 50 g of citric acid to adjust the pH of the system to 5.5. Continue stirring for 20 min to form a uniform slurry. Pour the slurry into a custom mold (internal cavity size 10 cm × 10 cm × 0.2 cm). The inner wall of the mold is pre-coated with polytetrafluoroethylene release agent to ensure that the composite porous carrier can be easily detached after molding.

[0022] Crosslinking and curing: The mold was placed in a constant temperature water bath at 60℃ and kept at this temperature for 2 hours to allow the polyvinylpyrrolidone molecular chains to undergo a crosslinking reaction with the polyurethane. Differential scanning calorimetry (DSC) analysis showed that the system exhibited a characteristic exothermic peak at 60℃, which lasted for 1.5 hours, indicating a complete crosslinking reaction. The tensile strength of the composite porous carrier increased from the initial 0.8 MPa to 1.5 MPa.

[0023] Surface modification: The cured composite porous carrier was removed from the mold and cut into circular pieces with a radius of 1 cm and a thickness of 2 mm (each piece weighing approximately 0.4 g). These pieces were then placed in a container containing 1000 mL of glycerol aqueous solution (8% by mass) at a liquor ratio of 1:25 and immersed in a 50°C constant temperature water bath for 1.5 h. Glycerol molecules modified the surface of the composite porous carrier through hydrogen bonding. Contact angle measurements showed that the contact angle of the composite porous carrier surface increased from 70° before modification to 90°, reducing the surface exudation rate of the attractant.

[0024] Drying and shaping: The modified composite porous carrier was rinsed four times with deionized water (500 mL each time) to remove unbound glycerol from the surface. It was then transferred to a vacuum freeze dryer, set at −40℃ and a vacuum of 5 Pa, and dried for 12 h. During freeze-drying, the internal water of the composite porous carrier sublimated into ice crystals, forming interconnected pores with a diameter of 80–150 μm. Mercury porosimetry analysis showed that the porosity of the composite porous carrier was 75 ± 3%, and the saturated adsorption capacity was 250 ± 10% of its own mass (i.e., 1 g of composite porous carrier can adsorb 2.5 g of the attractant mixture).

[0025] 3. Vector performance verification: Ten pieces of the prepared composite porous carrier were weighed using an electronic balance, and the mass deviation of a single piece was less than 0.02g. The compression rebound rate was over 90% when tested by a universal testing machine, and the carrier maintained its morphological stability under a pressure of 0.5MPa. After accelerated aging test (72h at 60℃ and 90% relative humidity), the porosity change rate was less than 5%, indicating that the composite porous carrier has good physical stability and structural consistency.

[0026] II. Preparation of Mosquito Slow-Release Attractants Example 1: S1 Raw Material Preparation Active ingredient: Octyl alcohol (purity 99%, density 0.824 g / cm³) 3 Lactic acid (mass fraction 85%, density 1.209 g / cm³) 3 Nonanal (purity 97%, density 0.831 g / cm³) 3 ), urea (analytical grade, purity 99.5%).

[0027] Weigh out the following components: octanol 500g, lactic acid 280g, nonanal 0.1g, urea 0.1g.

[0028] Instruments and equipment: electronic analytical balance (accuracy 0.1mg), three-necked flask (2000mL), digital display constant temperature magnetic stirrer (temperature control accuracy ±0.5℃), constant temperature water bath (temperature control range 0-100℃), vacuum dryer (ultimate vacuum degree -0.1MPa), ultrasonic cleaner (power 200-500W).

[0029] Preparation of S2 attractant mixture A three-necked flask was fixed to a magnetic stirrer, and 500g of octanol was added. Stirring was started (200 rpm), and the system temperature was stabilized at 25°C using a constant-temperature water bath. 280g of lactic acid was slowly added while stirring continuously for 10 minutes until the lactic acid was completely dispersed. At this point, the solution was a pale yellow and transparent. The absorbance of the solution at 280nm was measured using a UV-Vis spectrophotometer and remained stable at 0.35±0.02, indicating that the octanol and lactic acid were uniformly mixed.

[0030] Use a 1mL pipette to pipette 0.1g of weighed nonanal (nonanal density 0.831g / cm³). 3 The corresponding volume is 0.1g ÷ 0.831g / cm³. 3 Add approximately 0.12 mL of the solution to a three-necked flask at a rate of 0.1 mL / min. After the addition is complete, increase the stirring speed to 250 r / min and continue stirring for 20 min to allow the nonanal to dissolve completely. The solution color will turn pale yellow, and the transmittance will remain above 90%.

[0031] Finally, add 0.1g of urea, raise the water bath temperature to 35℃, and stir at 250r / min for 30min until the urea is completely dissolved. Turn off the stirring and allow to cool naturally to room temperature (25℃). Transfer the mixed solution to a 1000mL volumetric flask, rinse the inner wall of the three-necked flask three times with a small amount of deionized water, and transfer the rinsing solution to the volumetric flask. Add deionized water to bring the volume to 1000mL to obtain a homogeneous attractant mixture. Calculations show that the concentrations of octanol, lactic acid, nonanal, and urea in this mixture are 500mg / mL, 280mg / mL, 0.1mg / mL, and 0.1mg / mL, respectively. Store in a sealed container protected from light for later use.

[0032] S3 composite porous carrier pretreatment Take 200 circular composite porous carriers prepared above (each weighing 0.4g), place them in the cleaning tank of an ultrasonic cleaner, add deionized water until the composite porous carriers are completely submerged, set the power to 300W and the frequency to 40kHz, and ultrasonically clean for 8 minutes to remove residual preparation impurities on the surface. After cleaning, transfer the composite porous carriers to a forced-air drying oven, set the temperature to 65℃ and the air velocity to 1.5m / s, and dry for 4 hours until constant weight is reached (the difference between two consecutive weighings is less than 0.001g, at which point the mass of each composite porous carrier is stable at 0.39-0.41g).

[0033] The dried composite porous carrier is placed in a vacuum dryer, the dryer valve is closed, the vacuum pump is started, and the vacuum is slowly drawn to a pressure of -0.095MPa. This vacuum level is maintained for 30 minutes. The pressure fluctuation is monitored in real time by a vacuum gauge and controlled within ±0.003MPa to ensure that the air in the pores of the composite porous carrier is completely discharged.

[0034] S4 composite porous carrier loading attractant Under vacuum, the attractant mixture prepared in step S2 is slowly injected into the dryer through a separatory funnel. The attractant loading of each composite porous carrier is 80% of its saturated adsorption capacity. The saturated adsorption capacity of the composite porous carrier is 250% of its own mass, that is, each composite porous carrier can adsorb 0.4g × 250% = 1.0g of attractant. With a loading of 80%, each composite porous carrier needs to be loaded with 0.8g. 200 composite porous carriers require a total of 200 × 0.8g = 160g of attractant.

[0035] After injection, the vacuum valve was closed, and the mixture was kept under normal pressure for 4 hours. During this period, the dryer was gently shaken every 40 minutes to promote uniform penetration of the attractant into the pores of the composite porous carrier. Monitoring by weighing showed that the adsorption capacity of the composite porous carrier reached 85% of the theoretical value after 1 hour of immersion, 95% after 2 hours, and over 99% after 4 hours, indicating sufficient adsorption.

[0036] S5 Finished Product Post-processing Using stainless steel tweezers, remove the loaded composite porous carriers from the desiccator and place them one by one on a tray lined with double-layer qualitative filter paper. Gently press the sides of the composite porous carriers to absorb excess attractant from the surface. Then, transfer the composite porous carriers to a fume hood, control the ambient temperature at 25℃, relative humidity at 50%, and air velocity at 0.5m / s, and let them stand for 20 hours to allow any unadsorbed attractant on the surface to evaporate naturally.

[0037] Gas chromatography analysis showed that the concentration of volatile attractant in the fume hood decreased to 0.08 mg / m³. 3 The following steps yield the finished mosquito slow-release attractant, each tablet weighing approximately 1.17g, which is then sealed and stored in a brown wide-mouthed bottle for later use.

[0038] Example 2: S1 Raw Material Preparation Active ingredients: octanol, lactic acid, nonanal, urea (purity and density are the same as in Example 1).

[0039] Weigh out the following components: octanol 525g, lactic acid 310g, nonanal 0.125g, urea 0.125g.

[0040] Instruments and equipment: Same as in Example 1.

[0041] Preparation of S2 attractant mixture A three-necked flask was fixed to a magnetic stirrer. 525 g of octanol was added, and the stirring speed was 220 rpm. The water bath temperature was 26°C. 310 g of lactic acid was added, and the mixture was stirred for 12 min until the absorbance of the solution stabilized at 0.37 ± 0.02. 0.125 g of nonanal (approximately 0.15 mL) was pipetted and added dropwise at a rate of 0.12 mL / min. The stirring speed was increased to 260 rpm and maintained for 22 min. 0.125 g of urea was added, and the mixture was heated to 36°C and stirred for 32 min until dissolved. The mixture was then cooled to room temperature. The solution was transferred to a 1000 mL volumetric flask, rinsed with deionized water, and the volume was adjusted to 1000 mL to obtain the attractant mixture. The calculated concentrations of octanol, lactic acid, nonanal, and urea in the mixture were 525 mg / mL, 310 mg / mL, 0.125 mg / mL, and 0.125 mg / mL, respectively. The mixture was then sealed and stored.

[0042] S3 composite porous carrier pretreatment Take 200 composite porous carriers, ultrasonically clean them with a power of 320W for 9 minutes, and dry them in a 68℃ forced-air drying oven for 4.5 hours until constant weight. Transfer them to a vacuum dryer, evacuate to -0.096MPa, maintain for 32 minutes, with pressure fluctuations of ±0.003MPa.

[0043] S4 composite porous carrier loading attractant Each composite porous carrier has a loading of 82% of its saturated adsorption capacity, i.e., 0.4g × 250% × 82% = 0.82g. 200 carriers require a total of 200 × 0.82g = 164g of attractant. After vacuum injection, the carrier is immersed at atmospheric pressure for 4.5 hours, shaking every 35 minutes. After 4.5 hours, the adsorption capacity reaches 99.2% of the theoretical value.

[0044] S5 Finished Product Post-processing After removing residual liquid from the surface, the mixture was left to stand for 18 hours in a fume hood at 26°C, 52% relative humidity, and 0.6 m / s airflow. The concentration of volatile organic compounds decreased to 0.08 mg / m³. 3 Each finished product weighs approximately 1.19g.

[0045] Example 3: S1 Raw Material Preparation Active ingredients: octanol, lactic acid, nonanal, urea (purity and density are the same as in Example 1).

[0046] Weigh out the following components: octanol 550 g, lactic acid 350 g, nonanal 0.15 g, urea 0.15 g.

[0047] Instruments and equipment: Same as in Example 1.

[0048] Preparation of S2 attractant mixture Secure the three-necked flask to a magnetic stirrer, add 550 g of octanol, stir at 250 rpm, maintain a water bath temperature of 28°C, add 350 g of lactic acid, and stir for 15 min until the absorbance of the solution stabilizes at 0.40 ± 0.02. Using a pipette, pipette 0.15 g of nonanal (approximately 0.18 mL) and add it dropwise at a rate of 0.15 mL / min, increasing the stirring speed to 280 rpm and maintaining this for 25 min. Add 0.15 g of urea, heat to 38°C, and stir for 35 min until dissolved. Cool to room temperature.

[0049] The mixed solution was transferred to a 1000 mL volumetric flask, rinsed with deionized water, and brought to a final volume of 1000 mL to obtain the attractant mixture. The calculated concentrations of octanol, lactic acid, nonanal, and urea in the mixture were 550 mg / mL, 350 mg / mL, 0.15 mg / mL, and 0.15 mg / mL, respectively. The mixture was then sealed and stored.

[0050] S3 composite porous carrier pretreatment Take 200 composite porous carriers, ultrasonically clean them with a power of 350W for 10 minutes, and dry them in a 70℃ forced-air drying oven for 5 hours until constant weight. Transfer them to a vacuum dryer, evacuate to -0.098MPa, maintain for 35 minutes, with pressure fluctuations of ±0.003MPa.

[0051] S4 composite porous carrier loading attractant Each composite porous carrier has a loading of 85% of its saturated adsorption capacity, i.e., 0.4g × 250% × 85% = 0.85g. 200 carriers require a total of 200 × 0.85g = 170g of attractant. After vacuum injection, the carrier is immersed at atmospheric pressure for 5 hours, shaking every 30 minutes. After 5 hours, the adsorption capacity reaches 99.5% of the theoretical value.

[0052] S5 Finished Product Post-processing After removing residual liquid from the surface, the mixture was left to stand for 16 hours in a fume hood at 28°C, 55% relative humidity, and 0.8 m / s airflow, resulting in a volatile matter concentration of 0.08 mg / m³. 3 Each finished product weighs approximately 1.22g.

[0053] III. Setting the Comparison Scale Comparative Example 1: S1 Raw Material Preparation Active ingredients: octanol, lactic acid, nonanal, urea (purity and density are the same as in Example 1).

[0054] Weigh out the following components: octanol 480 g, lactic acid 260 g, nonanal 0.08 g, urea 0.08 g.

[0055] Instruments and equipment: Same as in Example 1.

[0056] Preparation of S2 attractant mixture The operating steps are the same as in Example 2 (stirring speed, temperature, and time are consistent). The mixed solution is transferred to a 1000 mL volumetric flask and diluted to volume to obtain the attractant mixture. Calculations show that the concentrations of octanol, lactic acid, nonanal, and urea in this mixture are 480 mg / mL, 260 mg / mL, 0.08 mg / mL, and 0.08 mg / mL, respectively.

[0057] S3 composite porous carrier pretreatment The cleaning, drying, and vacuum treatment conditions were the same as in Example 2 (ultrasonic power 320W, drying temperature 68℃, vacuum degree -0.096MPa).

[0058] S4 composite porous carrier loading attractant The loading amount of each composite porous carrier is the same as in Example 2 (0.82g), the immersion time is 4.5h, and the shaking frequency is the same.

[0059] S5 Finished Product Post-processing The finished product was obtained under the same post-processing environment as in Example 2 (temperature 26°C, humidity 52%, standing for 18 hours).

[0060] Comparative Example 2 (using an unmodified composite porous carrier): S1 Raw Material Preparation The active ingredients and weighing amounts are the same as in Example 2: octanol 525g, lactic acid 310g, nonanal 0.125g, urea 0.125g.

[0061] Instruments and equipment: Same as in Example 1.

[0062] Preparation of S2 attractant mixture Following the same steps and parameters as in Example 2, the volume was adjusted to 1000 mL to obtain an attractant mixture with the same concentration as in Example 2 (octanol 525 mg / mL, lactic acid 310 mg / mL, etc.).

[0063] S3 composite porous carrier pretreatment The composite porous carrier in this example is the product without glycerol surface modification (i.e., the surface modification step was omitted in the preparation process), and the remaining pretreatment steps (cleaning, drying, vacuum degassing) are the same as in Example 2. Testing showed that the surface contact angle of the unmodified composite porous carrier was 70°, and the saturated adsorption capacity was 240% of its own mass (slightly lower than that of the modified composite porous carrier).

[0064] S4 composite porous carrier loading attractant The loading amount and operation are the same as in Example 2 (0.82g per tablet, soaking for 4.5h).

[0065] S5 Finished Product Post-processing The same post-processing conditions as in Example 2 were used to obtain the finished product.

[0066] Comparative Example 3 (lacking nonanal): S1 Raw Material Preparation Active ingredients: octanol, lactic acid, urea (purity and density same as in Example 1), nonanaldehyde-free.

[0067] Weigh out the following components: octanol 525 g, lactic acid 310 g, urea 0.125 g.

[0068] Instruments and equipment: Same as in Example 1.

[0069] Preparation of S2 attractant mixture The nonanal addition step was omitted, and the remaining operations (mixing octanol and lactic acid, adding urea, and stirring parameters) were the same as in Example 2. The mixed solution was transferred to a 1000 mL volumetric flask and diluted to volume to obtain the attractant mixture. Calculations showed that the concentration of octanol in this mixture was 525 mg / mL, the concentration of lactic acid was 310 mg / mL, and the concentration of urea was 0.125 mg / mL.

[0070] S3 composite porous carrier pretreatment The same pretreatment conditions as in Example 2.

[0071] S4 composite porous carrier loading attractant The load and operation are the same as in Example 2.

[0072] S5 Finished Product Post-processing The same post-processing conditions as in Example 2 were used to obtain the finished product.

[0073] IV. Performance Testing and Data Analysis 1. Test methods and instruments Seduction rate test: Test subjects: Culex pipiens quinquefolius (laboratory-bred, adults 5-7 days after emergence, half male and half female, 200 mosquitoes per group) and Aedes albopictus (bred under the same conditions, 200 mosquitoes per group). They were fasted and deprived of water for 16 hours before the test.

[0074] Test environment: artificial climate chamber (temperature 28±1℃, relative humidity 65±5%, light cycle 12 h:12 h); mosquito breeding cage (1.2 m×1.2 m×1.2 m, nylon mesh, mesh size 0.12 mm).

[0075] Test Procedure: The finished attractant tablet was suspended in the center of the rearing cage (60 cm from the bottom). After mosquitoes were introduced, observations were conducted at 1, 7, 14, 21, and 28 days, with each observation lasting 90 minutes. The number of mosquitoes within 15 cm of the attractant was recorded using a high-definition camera (1080P resolution) to avoid human interference. Each test was repeated 5 times, and the average value was taken.

[0076] Calculation method: Sustained-release performance test: Instrument: Gas chromatograph (column DB-5, 30m×0.25mm×0.25µm; detector FID; injection port temperature 250℃; detector temperature 280℃; column temperature program: initial 50℃, hold for 3 min, increase to 220℃ at 8℃ / min, hold for 5 min).

[0077] Test procedure: The finished attractant tablet was placed in a sealed release chamber (volume 1000mL). The chamber temperature was 28℃ and the relative humidity was 65%. The released gas was collected by a gas sampling pump (flow rate 150mL / min) at 1d, 7d, 14d, 21d and 28d respectively, with 20mL sampled each time. After chromatographic analysis, the release concentration of each component was calculated by the external standard method, and then the percentage of the cumulative release amount to the initial load was obtained.

[0078] Adsorption performance test of composite porous carrier: Adsorption rate: Weigh the dried composite porous support. The sample was immersed in the attractant mixture and removed after 0.5h, 1h, 2h, and 4h, respectively. After the surface liquid was absorbed, the sample was weighed. Calculate the adsorption rate .

[0079] Adsorption capacity: After the composite porous carrier has reached saturation, the mass is measured. Calculate the saturated adsorption capacity .

[0080] 2. Test Results Table 1. Attraction rate (%) of Culex pipiens quinquefolius for each sample Table 2. Attraction rate (%) of each sample to Aedes albopictus Table 3. Cumulative release rate of major components (%, 28 days) Table 4 Adsorption performance parameters of composite porous carrier 3. Data Analysis and Conclusions As shown in Table 1, in Examples 1 to 3, with the increase of the mass of octanol, lactic acid, nonanal, and urea, the concentration of the attractant mixture formed after volume adjustment increased sequentially, and the attraction rates for Culex pipiens quinquefolius and Aedes albopictus also increased accordingly. Example 3 showed the best attraction effect, with an attraction rate of 68.3% for Culex pipiens quinquefolius and 51.3% for Aedes albopictus at 28 days. This indicates that within the formulation range of the present invention, higher concentrations of active ingredients can enhance the attraction to mosquitoes, and the synergistic effect between the components is more significant. Comparative Example 1, due to the lower mass of each component, had a concentration lower than that of the examples after volume adjustment, resulting in a significantly reduced attraction effect. At 28 days, the attraction rate for Culex pipiens quinquefolius was only 40.1%, only 58.7% of that of Example 3, indicating that excessively low concentrations of active ingredients lead to a significant weakening of the attraction effect, failing to meet the requirements for long-term attraction.

[0081] As shown in Table 2, in Examples 1 to 3, the composite porous carriers modified with glycerol showed cumulative release rates of less than 70% for each component after 28 days, with nonanal showing the slowest release (54.5%-58.%). This is because the modified composite porous carrier has a larger surface contact angle, resulting in stronger interaction with components such as nonanal, effectively slowing down the release rate. Comparative Example 2 used an unmodified composite porous carrier, which had a smaller surface contact angle and weaker binding effect on the attractant, leading to a faster release rate of each component, with a cumulative release rate of 68.7%-75.4% after 28 days. This rapid release resulted in a large consumption of the attractant in a short time; the attraction rate for Culex pipiens quinquefasciatus after 28 days was only 42.5%, far lower than the 64.2% in Example 2, demonstrating that surface modification is a key process for achieving sustained release and extending the duration of action.

[0082] As shown in Table 3, Comparative Example 3, due to the absence of nonanal, exhibited a significantly lower attraction rate despite having the same concentrations of octanol and lactic acid as Example 2. At 1 day, the attraction rate for Culex pipiens quinquefasciatus was 55.8%, only 66.8% of that in Example 2; at 28 days, it decreased to 30.5%, a reduction of 52.5%. This indicates that nonanal, as a signaling molecule sensitive to the olfaction of mosquitoes, can synergistically enhance the attraction effect with octanol and lactic acid, making it an indispensable component of the formulation.

[0083] As shown in Table 4, the saturated adsorption capacity of the composite porous carrier used in the examples reached 250±10%, and the adsorption rate reached 99.2% after 4 hours, demonstrating rapid and sufficient loading of the attractant. The high adsorption capacity ensures that the composite porous carrier can accommodate sufficient attractant, and combined with its sustained-release characteristics, the attractant maintains a certain concentration even after 28 days, continuing to exert its attracting effect. In contrast, the unmodified composite porous carrier exhibits slightly weaker adsorption performance, further affecting the long-term effectiveness of the attractant.

[0084] In summary, this invention prepares an attractant mixture with concentrations of 500-550 mg / mL octanol, 280-350 mg / mL lactic acid, 0.1-0.15 mg / mL nonanal, and 0.1-0.15 mg / mL urea by weighing specific masses of octanol, lactic acid, nonanal, and urea. This mixture is then loaded onto a glycerol-modified composite porous carrier, achieving highly efficient and long-lasting attraction for mosquitoes. Example 3 showed the best effect, maintaining a high attraction rate for 28 days, demonstrating significant practical application value.

[0085] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A mosquito slow-release attractant, characterized in that, The product comprises an active ingredient and a composite porous carrier. The active ingredient comprises the following components in parts by weight: 500-550 parts octanol, 280-350 parts lactic acid, 0.1-0.15 parts nonanal, and 0.1-0.15 parts urea. The active ingredient is uniformly adsorbed into the pores of the composite porous carrier through a loading process.

2. The mosquito slow-release attractant as described in claim 1, characterized in that, The composite porous support was prepared by the following method: (a) Raw material mixing: Polyurethane particles with a particle size of 50-80μm, nano-hydroxyapatite with a particle size of 30-50nm, and polyvinylpyrrolidone with a molecular weight of 50,000-60,000 are mixed at a mass ratio of 15:2:1 at 60-80℃ and a rotation speed of 600-900r / min for 20-40 minutes. (b) Pore control: Add deionized water and citric acid to the mixed substrate, adjust the pH of the system to 5.0-6.0, stir to form a uniform slurry and then inject it into the mold; (c) Crosslinking and curing: Place the mold in an environment of 55-65℃ and keep it warm for 1.5-2.5 hours to allow the polyvinylpyrrolidone molecular chains to undergo a crosslinking reaction with the polyurethane particles; (d) Surface modification: Immerse the cured carrier in a 5%-10% glycerol aqueous solution and keep it at a constant temperature of 45-55℃ for 1-2 hours; (e) Drying and shaping: After rinsing the surface-modified carrier, freeze-dry it for 10-14 hours at -40℃ and vacuum degree below 10Pa to obtain a composite porous carrier with a porosity of 70%-80%, a saturated adsorption capacity of 240%-260% of its own mass, and a compression resilience greater than 90%.

3. The mosquito slow-release attractant as described in claim 1, characterized in that, The loading process includes the following steps: S1: Mix octanol, lactic acid, nonanal, and urea according to the specified ratio, and bring the volume to 1000 mL to form an attractant mixture, wherein the concentration of octanol is 500-550 mg / mL, the concentration of lactic acid is 280-350 mg / mL, the concentration of nonanal is 0.1-0.15 mg / mL, and the concentration of urea is 0.1-0.15 mg / mL; S2: The composite porous carrier is ultrasonically cleaned and then dried at 65-70℃ to constant weight. S3: Place the dried composite porous carrier in a vacuum environment and maintain it for 30-35 minutes under a vacuum degree not lower than -0.095 MPa; S4: Under vacuum, inject the attractant mixture into the composite porous carrier, then restore normal pressure and soak for 3-5 hours, shaking the container intermittently during the process; S5: Remove the loaded composite porous carrier, absorb the residual liquid on the surface, and let it stand for 16-20 hours under ventilation until the concentration of surface volatiles is lower than 0.1 mg / m³, to obtain the mosquito slow-release attractant.

4. The mosquito slow-release attractant as described in claim 3, characterized in that, In step S2, the ultrasonic cleaning power is 300-350W, and the cleaning time is 8-10 minutes.

5. The mosquito slow-release attractant as described in claim 3, characterized in that, In step S3, the degassing is maintained for 30-35 minutes under a vacuum of not less than -0.095 MPa.

6. The mosquito slow-release attractant as described in claim 3, characterized in that, In step S4, the attractant loading of each composite porous carrier is 80%-85% of its saturated adsorption capacity.

7. The mosquito slow-release attractant as described in claim 3, characterized in that, The composite porous carrier has a circular sheet structure with a single sheet mass of 0.39-0.41 g.

8. A mosquito slow-release attractant as described in any one of claims 1, characterized in that, The mass of a single piece of the composite porous carrier loaded with the attractant is 1.17-1.22 g.

9. The application of the mosquito slow-release attractant according to any one of claims 1 to 8, characterized in that, The mosquito slow-release attractant is used to trap Culex pipiens quinquefasciatus and / or Aedes albopictus.

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