Compound insecticide containing plant extract and preparation process thereof

Abstract

The invention provides a composite pesticide containing plant extracts and a preparation process thereof, and belongs to the technical field of pesticide preparation. The preparation process comprises the following steps: preparing composite carrier powder; preparing modified composite carrier powder; preparing the corydalis bungeana extract; and preparing the composite insecticide. The preparation method comprises the following steps: firstly dispersing nano calcium carbonate powder in deionized water, then adding a mixed solution of a calcium nitrate solution and a diammonium hydrogen phosphate solution, carrying out a hydrothermal reaction to prepare composite carrier powder of nano calcium carbonate and hydroxyapatite, loading a corydalis bungeana extract and veratrine by using the composite carrier powder, and carrying out hydrothermal reaction on the corydalis bungeana extract and the veratrine so as to obtain the composite material. According to the present invention, with the application of the composite carrier powder, the prepared composite pesticide can have the slow release effect, the insecticidal action time can be prolonged, the pesticide application frequency can be reduced, and the environmental pollution can be reduced, and in addition, after the composite carrier powder is modified, the loading rate of the corydalis bungeana extract and the veratrine can be improved so as to enhance the insecticidal effect of the composite pesticide.

Description

Technical Field

[0001] The invention relates to the technical field of pesticide preparation, and in particular to a composite insecticide containing plant extracts and a preparation process thereof. Background Art

[0002] In agricultural production, pest control has always been a key link in ensuring crop yield and quality. Although traditional chemical pesticides have high efficiency and rapid insecticidal effects, their long-term and large-scale use has led to many serious problems. For example, organochlorine pesticides, such as DDT, which were widely used in the early days, have significant insecticidal effects, but their chemical properties are extremely stable and difficult to degrade in the environment. Their half-life is as long as several years or even decades. This not only causes them to continue to remain in the soil and water, and continue to accumulate through the food chain, causing lasting and widespread damage to the ecosystem, seriously threatening human health, but also easily leads to a sharp increase in pest resistance, which greatly reduces the effectiveness of prevention and control.

[0003] As a natural insecticide resource, botanical insecticides have attracted extensive attention due to their environmental friendliness, diverse biological activities, low toxicity, and low resistance to drug resistance. However, plant extracts have poor stability and are easily decomposed by environmental factors such as light, temperature, and humidity, resulting in a decrease in the content of active ingredients and a difficult to sustain insecticidal effect.

[0004] Therefore, it is necessary to provide a composite insecticide containing plant extracts which is environmentally friendly and has a long-lasting insecticidal effect and a preparation process thereof. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a composite insecticide containing plant extracts and a preparation process thereof.

[0006] A preparation process of a composite insecticide containing plant extracts comprises the following steps: S1: Preparation of composite carrier powder The nano calcium carbonate powder is dispersed in deionized water, and then added into a mixed solution of calcium nitrate solution and diammonium hydrogen phosphate solution to react to obtain a composite carrier powder; S2: Preparation of modified composite carrier powder The composite carrier powder is dispersed in toluene, and diphenyl chlorophosphate is added for activation, and then octadecanoyl chloride solution and dodecylamine are added in sequence for reaction to obtain a modified composite carrier powder; S3: Preparation of Corydalis extract Extracting Corydalis chinensis with an ethanol solution to obtain a Corydalis chinensis extract; S4: Preparation of compound insecticide The modified composite carrier powder is used to load the Corydalis extract, veratrine and matrine respectively, and then mixed with a dispersant, a wetting agent, a disintegrant and an aqueous binder solution for granulation to obtain a composite insecticide.

[0007] Furthermore, S1 specifically includes the following steps: S1.1: Add nano calcium carbonate powder into deionized water at a solid-liquid ratio of 1 g: (20-30) mL, and ultrasonically disperse for 30-40 min to obtain a nano calcium carbonate dispersion; S1.2: Add calcium nitrate tetrahydrate and diammonium hydrogen phosphate into deionized water respectively, stir and dissolve thoroughly to prepare 0.5 mol / L calcium nitrate solution and 0.3 mol / L diammonium hydrogen phosphate solution; S1.3: Mix the calcium nitrate solution and the diammonium phosphate solution, add 5 wt % PEG-6000, and stir well to obtain a mixed solution; S1.4: Add the nano calcium carbonate dispersion to the mixed solution in a volume ratio of 1:(2-3), add 25% ammonia water to maintain the pH at 10.3-10.5, and stir for 2-3 hours to obtain a precursor solution; S1.5: The precursor solution is transferred to a high-pressure reactor, heated and stirred at 160-180°C for 8-10 hours, and after cooling, centrifugally washed and freeze-dried to obtain a composite carrier powder.

[0008] Furthermore, S2 specifically includes the following steps: S2.1: Add the above composite carrier powder to toluene at a solid-liquid ratio of 1g: (15-25)mL, then add triethylamine, and after ultrasonic dispersion for 30-40min, add diphenyl chlorophosphate, and heat under reflux at 80-90°C for 6-8h to obtain an activated carrier dispersion; S2.2: Add octadecanoyl chloride to toluene at a solid-liquid ratio of 1 g: (10-12) mL, stir thoroughly, and prepare an octadecanoyl chloride solution; S2.3: Add the above-mentioned octadecanoyl chloride solution to the above-mentioned activated carrier dispersion in a volume ratio of 1:(3-5), heat and react at 70-80°C for 6-7h under nitrogen protection, then add dodecylamine, adjust the pH to 9-9.2 with 0.1mol / L sodium hydroxide solution, continue to heat and reflux at 70-80°C for 8-10h, filter, wash and dry to obtain a modified composite carrier powder.

[0009] Furthermore, S3 specifically includes the following steps: S3.1: Clean and dry the fresh Corydalis, place in an oven at 45-50°C until it becomes brittle, and then crush and sieve through 80-120 mesh to obtain Corydalis powder; S3.2: Add the above-mentioned Corydalis powder to 90% ethanol solution at a solid-liquid ratio of 1g: (10-20)mL, ultrasonically treat at 100-200W for 20-30min, and then soak for 20-24h. After filtering, place the filtrate in a 55℃ rotary evaporator, pressurize and concentrate to a paste, and then freeze-dry to obtain the Corydalis extract.

[0010] Furthermore, S4 specifically includes the following steps: S4.1: Add the Corydalis extract obtained in step S3.2 to 90% ethanol solution at a solid-liquid ratio of 1 g: (20-30) mL, stir for 20-30 min, and then ultrasonically disperse for 10-20 min, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1 g: (30-40) mL, ultrasonically load for 40-50 min, centrifugally filter, wash and dry to obtain Corydalis loaded powder; S4.2: Add veratridine to anhydrous ethanol at a solid-liquid ratio of 1 g: (20-30) mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1 g: (30-40) mL, ultrasonically load for 30-40 min, centrifuge, filter, wash and dry to obtain veratridine-loaded powder; S4.3: Add matrine to anhydrous ethanol at a solid-liquid ratio of 1 g: (90-100) mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1 g: (30-40) mL, ultrasonically load for 30-40 min, centrifuge, filter, wash and dry to obtain matrine-loaded powder; S4.4: Add the above-mentioned Corydalis powder, the above-mentioned Veratrine powder, the above-mentioned Matrine powder, dispersant, wetting agent and disintegrant into a mixer, mix them thoroughly and evenly, then add 20% by mass aqueous solution of binder, and perform extrusion granulation. After drying and sieving, a composite insecticide is obtained.

[0011] Furthermore, the molar ratio of calcium element in the calcium nitrate solution to phosphorus element in the diammonium phosphate solution is 5:3.

[0012] Furthermore, in step S2.1, the volume ratio of triethylamine to toluene is 1:(38-42), and the volume ratio of diphenyl chlorophosphate to toluene is 1:(2.3-2.5).

[0013] Furthermore, the molar ratio of dodecylamine to octadecanoyl chloride is 1:2.

[0014] Furthermore, the weight percentage of each component in the composite insecticide is: 10-20% matrine powder, 5-6% dispersant, 2-3% wetting agent, 18-20% disintegrant and 3-5% binder, and the remainder is corydalis powder and veratridine powder, and the mass ratio of corydalis powder to veratridine powder is (3.5-4.5):1; wherein the dispersant is lignin sulfonate; the wetting agent is sodium dodecyl sulfate; the disintegrant is any one of sodium sulfate, calcium sulfate, sodium bicarbonate, magnesium chloride and sodium chloride; and the binder is any one of starch, carboxymethyl cellulose, gelatin and carboxyethyl cellulose.

[0015] Furthermore, a composite insecticide containing a plant extract is prepared by any of the above-mentioned processes for preparing a composite insecticide containing a plant extract.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The present invention prepares a composite carrier powder of nano calcium carbonate and hydroxyapatite by first dispersing nano calcium carbonate powder in deionized water, then adding a mixed solution of calcium nitrate solution and diammonium hydrogen phosphate solution, and performing a hydrothermal reaction. The composite carrier powder is used to load Corydalis extract, veratridine and matrine, so that not only the stability thereof can be improved, but also the prepared composite insecticide can have a sustained-release effect, prolong the insecticidal action time, reduce the number of times of application, and reduce environmental pollution. In addition, after the composite carrier powder is activated by diphenyl chlorophosphate, octadecanoyl chloride solution and dodecylamine are added in sequence to react respectively. After the composite carrier powder is modified, its surface properties can be changed, its hydrophobicity can be enhanced, and the interaction between the composite carrier powder and the Corydalis extract and the veratridine can be enhanced, so as to improve the loading rate of the composite insecticide on the Corydalis extract and the veratridine, thereby enhancing the insecticidal effect of the composite insecticide.

[0017] 2. The present invention extracts Corydalis with an ethanol solution to prepare a Corydalis extract, and then mixes the Corydalis extract with veratridine to prepare a composite insecticide. On the one hand, since veratridine acts on sodium channels and the Corydalis extract acts on dopamine receptors, the combination of the two can simultaneously interfere with the nerve conduction and movement control of pests to enhance the insecticidal effect. On the other hand, the active ingredients of the Corydalis extract can inhibit the detoxification enzymes in the pests, delay their metabolism of veratridine, and thus prolong their action time. In addition, the polar components in the Corydalis extract can destroy the waxy layer of the insect cuticle and promote the penetration and absorption of veratridine. Therefore, the Corydalis extract and veratridine have a synergistic insecticidal effect. When the two are used in combination, they have a better insecticidal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable those skilled in the relevant art to make and use the present disclosure.

[0019] Figure 1 The present invention is a flow chart of the preparation process of the composite insecticide containing plant extracts used in the embodiments of the present invention.

[0020] Figure 2 This is a 72h cumulative release rate curve of the Corydalis extract-loaded powder and the Veratridine-loaded powder prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] The following describes in detail a composite insecticide containing plant extracts and a preparation process thereof provided by the present invention in conjunction with the accompanying drawings and specific embodiments.

[0022] Example 1 A preparation process of a composite insecticide containing plant extracts, such as Figure 1 As shown, the following steps are included: S1: Preparation of composite carrier powder S1.1: Add nano calcium carbonate powder into deionized water at a solid-liquid ratio of 1g:20mL, and ultrasonically disperse for 30 minutes to obtain a nano calcium carbonate dispersion; S1.2: Add calcium nitrate tetrahydrate and diammonium hydrogen phosphate into deionized water respectively, stir and dissolve thoroughly to prepare 0.5 mol / L calcium nitrate solution and 0.3 mol / L diammonium hydrogen phosphate solution; S1.3: Mix the calcium nitrate solution and the diammonium hydrogen phosphate solution, add 5wt% PEG-6000, and stir and mix thoroughly to obtain a mixed solution, wherein the molar ratio of calcium element in the calcium nitrate solution to phosphorus element in the diammonium hydrogen phosphate solution is 5:3; S1.4: Add the nano calcium carbonate dispersion to the mixed solution at a volume ratio of 1:2, add 25% ammonia water to maintain the pH at 10.3, and stir for 2 hours to obtain a precursor solution; S1.5: The precursor solution is transferred to a high-pressure reactor, heated and stirred at 160°C for 8 hours, cooled, centrifuged, washed and freeze-dried to obtain a composite carrier powder; S2: Preparation of modified composite carrier powder S2.1: Add the above composite carrier powder to toluene at a solid-liquid ratio of 1g:15mL, then add triethylamine, and after ultrasonic dispersion for 30min, add diphenyl chlorophosphate, and heat under reflux at 80°C for 6h to obtain an activated carrier dispersion, wherein the volume ratio of triethylamine to toluene is 1:38, and the volume ratio of diphenyl chlorophosphate to toluene is 1:2.3; S2.2: Add octadecanoyl chloride to toluene at a solid-liquid ratio of 1 g:10 mL, stir thoroughly, and prepare an octadecanoyl chloride solution; S2.3: Add the above-mentioned octadecanoyl chloride solution to the above-mentioned activated carrier dispersion at a volume ratio of 1:3, heat and react at 70°C for 6 hours under nitrogen protection, then add dodecylamine, adjust the pH to 9 with 0.1 mol / L sodium hydroxide solution, continue to heat and reflux at 70°C for 8 hours, filter, wash and dry to obtain a modified composite carrier powder, wherein the molar ratio of dodecylamine to octadecanoyl chloride is 1:2; S3: Preparation of Corydalis extract S3.1: Clean and dry the fresh Corydalis, place in a 45°C oven and dry until crisp, then crush and sieve through 80 mesh to obtain Corydalis powder; S3.2: Add the above-mentioned Corydalis powder to 90% ethanol solution at a solid-liquid ratio of 1g:10mL, treat with ultrasound at 100W for 20min, soak for 20h, filter, place the filtrate in a rotary evaporator at 55℃, pressurize and concentrate to a paste, and then freeze-dry to obtain Corydalis extract; S4: Preparation of compound insecticide S4.1: Add the Corydalis extract obtained in step S3.2 to 90% ethanol solution at a solid-liquid ratio of 1g:20mL, stir for 20min, and then ultrasonically disperse for 10min, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1g:30mL, ultrasonically load for 40min, centrifugally filter, wash and dry to obtain Corydalis loaded powder; S4.2: Add veratridine to anhydrous ethanol at a solid-liquid ratio of 1 g:10 mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1:30 mL, ultrasonically load for 30 min, centrifuge, filter, wash and dry to obtain veratridine-loaded powder; S4.3: Add matrine to anhydrous ethanol at a solid-liquid ratio of 1g:90mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1g:30mL, ultrasonically load for 30min, centrifuge, filter, wash and dry to obtain matrine-loaded powder; S4.4: Add the above-mentioned Corydalis powder, the above-mentioned Veratridine powder, the above-mentioned Matrine powder, dispersant, wetting agent and disintegrant into a mixer, mix thoroughly and evenly, then add 20% by mass of an aqueous binder solution, and perform extrusion granulation. After drying and sieving, a composite insecticide is obtained, wherein the weight percentage of each component in the composite insecticide is: 10% Matrine powder, 5% lignin sulfonate dispersant, 2% sodium dodecyl sulfate wetting agent, 18% sodium sulfate and 3% starch, and the remainder is Corydalis powder and Veratridine powder, and the mass ratio of Corydalis powder to Veratridine powder is 3.5:1.

[0023] Example 2 A preparation process of a composite insecticide containing plant extracts, such as Figure 1 As shown, the following steps are included: S1: Preparation of composite carrier powder S1.1: Add nano calcium carbonate powder into deionized water at a solid-liquid ratio of 1g:25mL, and ultrasonically disperse for 35 minutes to obtain a nano calcium carbonate dispersion; S1.2: Add calcium nitrate tetrahydrate and diammonium hydrogen phosphate into deionized water respectively, stir and dissolve thoroughly to prepare 0.5 mol / L calcium nitrate solution and 0.3 mol / L diammonium hydrogen phosphate solution; S1.3: Mix the calcium nitrate solution and the diammonium hydrogen phosphate solution, add 5wt% PEG-6000, and stir and mix thoroughly to obtain a mixed solution, wherein the molar ratio of calcium element in the calcium nitrate solution to phosphorus element in the diammonium hydrogen phosphate solution is 5:3; S1.4: Add the nano calcium carbonate dispersion to the mixed solution at a volume ratio of 1:2.5, add 25% ammonia water to maintain the pH at 10.4, and stir the reaction for 2.5 hours to obtain a precursor solution; S1.5: The precursor solution is transferred to a high-pressure reactor, heated and stirred at 170°C for 9 hours, cooled, centrifuged, washed and freeze-dried to obtain a composite carrier powder; S2: Preparation of modified composite carrier powder S2.1: Add the above composite carrier powder to toluene at a solid-liquid ratio of 1g:20mL, then add triethylamine, and after ultrasonic dispersion for 35 minutes, add diphenyl chlorophosphate, and heat under reflux at 85°C for 7 hours to obtain an activated carrier dispersion, wherein the volume ratio of triethylamine to toluene is 1:40, and the volume ratio of diphenyl chlorophosphate to toluene is 1:2.4; S2.2: Add octadecanoyl chloride to toluene at a solid-liquid ratio of 1 g:11 mL, stir thoroughly, and prepare an octadecanoyl chloride solution; S2.3: Add the above-mentioned octadecanoyl chloride solution to the above-mentioned activated carrier dispersion at a volume ratio of 1:4, heat and react at 75°C for 6.5 hours under nitrogen protection, then add dodecylamine, adjust the pH to 9.1 with 0.1 mol / L sodium hydroxide solution, continue to heat and reflux at 75°C for 9 hours, filter, wash and dry to obtain a modified composite carrier powder, wherein the molar ratio of dodecylamine to octadecanoyl chloride is 1:2; S3: Preparation of Corydalis extract S3.1: Clean and dry the fresh Corydalis, place in an oven at 45°C until it becomes brittle, and then crush and sieve through 100 meshes to obtain Corydalis powder; S3.2: Add the above-mentioned Corydalis powder to 90% ethanol solution at a solid-liquid ratio of 1g:15mL, treat with ultrasound at 150W for 25min, soak for 22h, filter, place the filtrate in a rotary evaporator at 55℃, pressurize and concentrate to a paste, and then freeze-dry to obtain Corydalis extract; S4: Preparation of compound insecticide S4.1: Add the Corydalis extract obtained in step S3.2 to 90% ethanol solution at a solid-liquid ratio of 1g:25mL, stir for 25min, and then ultrasonically disperse for 15min, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1g:35mL, ultrasonically load for 45min, centrifugally filter, wash and dry to obtain Corydalis loaded powder; S4.2: Add veratridine to anhydrous ethanol at a solid-liquid ratio of 1 g:15 mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1:35 mL, ultrasonically load for 35 min, centrifuge, filter, wash and dry to obtain veratridine-loaded powder; S4.3: Add matrine to anhydrous ethanol at a solid-liquid ratio of 1g:95mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1g:35mL, ultrasonically load for 35min, centrifuge, filter, wash and dry to obtain matrine-loaded powder; S4.4: Add the above-mentioned Corydalis powder, the above-mentioned Veratridine powder, the above-mentioned Matrine powder, dispersant, wetting agent and disintegrant into a mixer, mix thoroughly and evenly, then add a 20% by mass aqueous solution of binder, and perform extrusion granulation. After drying and sieving, a composite insecticide is obtained, wherein the weight percentage of each component in the composite insecticide is: 15% Matrine powder, 5.5% lignin sulfonate dispersant, 2.5% sodium dodecyl sulfate wetting agent, 19% calcium sulfate and 4% carboxymethyl cellulose, and the remainder is Corydalis powder and Veratridine powder, and the mass ratio of Corydalis powder to Veratridine powder is 4:1.

[0024] Example 3 A preparation process of a composite insecticide containing plant extracts, such as Figure 1 As shown, the following steps are included: S1: Preparation of composite carrier powder S1.1: Add nano calcium carbonate powder into deionized water at a solid-liquid ratio of 1g:30mL, and ultrasonically disperse for 40 minutes to obtain a nano calcium carbonate dispersion; S1.2: Add calcium nitrate tetrahydrate and diammonium hydrogen phosphate into deionized water respectively, stir and dissolve thoroughly to prepare 0.5 mol / L calcium nitrate solution and 0.3 mol / L diammonium hydrogen phosphate solution; S1.3: Mix the calcium nitrate solution and the diammonium hydrogen phosphate solution, add 5wt% PEG-6000, and stir and mix thoroughly to obtain a mixed solution, wherein the molar ratio of calcium element in the calcium nitrate solution to phosphorus element in the diammonium hydrogen phosphate solution is 5:3; S1.4: Add the nano-calcium carbonate dispersion to the mixed solution at a volume ratio of 1:3, add 25% ammonia water to maintain the pH at 10.5, and stir for 3 hours to obtain a precursor solution; S1.5: The precursor solution is transferred to a high-pressure reactor, heated and stirred at 180°C for 10 hours, cooled, centrifuged, washed and freeze-dried to obtain a composite carrier powder; S2: Preparation of modified composite carrier powder S2.1: Add the above composite carrier powder to toluene at a solid-liquid ratio of 1g:25mL, then add triethylamine, and after ultrasonic dispersion for 40min, add diphenyl chlorophosphate, and heat under reflux at 90°C for 8h to obtain an activated carrier dispersion, wherein the volume ratio of triethylamine to toluene is 1:42, and the volume ratio of diphenyl chlorophosphate to toluene is 1:2.5; S2.2: Add octadecanoyl chloride to toluene at a solid-liquid ratio of 1 g:12 mL, stir thoroughly, and prepare an octadecanoyl chloride solution; S2.3: Add the above-mentioned octadecanoyl chloride solution to the above-mentioned activated carrier dispersion at a volume ratio of 1:5, heat and react at 80°C for 7 hours under nitrogen protection, then add dodecylamine, adjust the pH to 9.2 with 0.1 mol / L sodium hydroxide solution, continue to heat and reflux at 80°C for 10 hours, filter, wash and dry to obtain a modified composite carrier powder, wherein the molar ratio of dodecylamine to octadecanoyl chloride is 1:2; S3: Preparation of Corydalis extract S3.1: Clean and dry the fresh Corydalis, place in a 50°C oven and dry until crisp, then crush and sieve through 80-120 mesh to obtain Corydalis powder; S3.2: Add the above-mentioned Corydalis powder to 90% ethanol solution at a solid-liquid ratio of 1g:20mL, treat with ultrasound at 200W for 30min, soak for 24h, filter, place the filtrate in a rotary evaporator at 55℃, pressurize and concentrate to a paste, and then freeze-dry to obtain Corydalis extract; S4: Preparation of compound insecticide S4.1: Add the Corydalis extract obtained in step S3.2 to 90% ethanol solution at a solid-liquid ratio of 1g:30mL, stir for 30min, and then ultrasonically disperse for 20min, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1g:40mL, ultrasonically load for 50min, centrifugally filter, wash and dry to obtain Corydalis loaded powder; S4.2: Add veratridine to anhydrous ethanol at a solid-liquid ratio of 1 g:20 mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1:40 mL, ultrasonically load for 40 min, centrifuge, filter, wash and dry to obtain veratridine-loaded powder; S4.3: Add matrine to anhydrous ethanol at a solid-liquid ratio of 1 g: 100 mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1 g: 40 mL, ultrasonically load for 40 min, centrifuge, filter, wash and dry to obtain matrine-loaded powder; S4.4: Add the above-mentioned Corydalis powder, the above-mentioned Veratridine powder, the above-mentioned Matrine powder, dispersant, wetting agent and disintegrant into a mixer, mix thoroughly and evenly, then add 20% by mass of an aqueous binder solution, and perform extrusion granulation. After drying and sieving, a composite insecticide is obtained, wherein the weight percentage of each component in the composite insecticide is: 20% Matrine powder, 6% lignin sulfonate dispersant, 3% sodium dodecyl sulfate wetting agent, 20% sodium bicarbonate and 5% gelatin, and the remainder is Corydalis powder and Veratridine powder, and the mass ratio of Corydalis powder to Veratridine powder is 4.5:1.

[0025] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that step S2 is removed, and the modified composite carrier powder in steps S4.1 and S4.2 is replaced by an equal amount of the composite carrier powder prepared in step S1.5.

[0026] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the Veratridine-loaded powder in step S4.3 is replaced by an equal amount of Corydalis-loaded powder.

[0027] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the Corydalis powder in step S4.3 is replaced by an equal amount of Veratridine powder.

[0028] Test Case Test 1: Weigh 10 mg of the corydalis powder and the veratridine powder prepared in Example 1 respectively and put them into a conical flask containing 50 mL of release medium (volume of anhydrous ethanol: volume of deionized water = 3:1), simulate the release behavior at 25°C, and remove 3 mL of the release medium at 2h, 4h, 8h, 12h, 24h, 48h, and 72h, respectively, detect the absorbance, and add 3 mL of blank release medium, then calculate and draw the cumulative release rate curve, as shown in FIG. Figure 2 shown.

[0029] from Figure 2It can be seen that the cumulative release rate of the Corydalis powder and the Veratridine powder prepared in Example 1 is about 95% in 72h, which has a sustained release effect. That is to say, by first dispersing the nano-calcium carbonate powder in deionized water, and then adding a mixed solution of calcium nitrate solution and diammonium hydrogen phosphate solution to carry out hydrothermal reaction, a composite carrier powder of nano-calcium carbonate and hydroxyapatite is prepared. After the Corydalis extract and Veratridine are loaded with the composite carrier powder, not only can the stability be improved, but also the prepared composite insecticide can have a sustained release effect, prolong the insecticidal action time, reduce the number of applications, and reduce environmental pollution.

[0030] Test 2: Liquid chromatography was used to detect the mass concentrations of Corydalis extract, veratrine and matrine in the filtrate obtained by centrifugation after ultrasonic loading in steps S4.1-S4.3 of Examples 1-3 and Comparative Example 1. The loading rate was calculated by the following formula: Loading rate (%) = [initial mass of Corydalis extract (or veratridine / matrine) - mass concentration of Corydalis extract (or veratridine / matrine) in the filtrate × volume of filtrate] / initial mass of Corydalis extract (or veratridine / matrine) × 100%. Three parallel experiments were performed in each group, and the average value was taken. The results are shown in Table 1.

[0031] Table 1: Test results of Corydalis extract and Veratrine loading rate

[0032] As can be seen from Table 1, in Comparative Example 1, after the composite carrier powder is not modified, the loading rates of the prepared composite carrier powder for Corydalis extract, veratridine and matrine are much lower than those in Example 1. This shows that after the composite carrier powder is activated by diphenyl chlorophosphate, octadecanoyl chloride solution and dodecylamine are added in sequence to react respectively, and the composite carrier powder is modified, its loading rate for Corydalis extract, veratridine and matrine can be increased, thereby enhancing the insecticidal effect of the composite insecticide.

[0033] Test 3: Aphid control effect test of compound insecticide Test method: 100m 2 The cotton test field with uniform soil, gentle terrain and good drainage and irrigation was used as the test site, and was randomly divided into 5 groups, namely, Example 1 Group, Example 2 Group, Example 3 Group, Comparative Example 2 Group and Comparative Example 3 Group, each group had 20m 2 , use electric sprayers to spray pesticides to prevent and control aphids, and use conventional cotton field management methods during the application period.

[0034] Application: The Example 1-3 group and the Comparative Example 2-3 group were sprayed with the composite insecticide prepared in Example 1-3 and Comparative Example 2-3, respectively, with a dosage of 30 g / mu and a spray-water content of 30 kg / mu.

[0035] Statistical method: The number of aphids was counted by five-point sampling method before application, 1 day, 3 days and 15 days after application, and the average value was taken. The insect population reduction rate was calculated according to the following formula: Insect population reduction rate (%) = (number of live insects before application - number of live insects after application) / number of live insects before application × 100%. The results are shown in Table 2.

[0036] Table 2: Aphid control effects of compound insecticides

[0037] As can be seen from Table 2, the composite insecticides prepared by using only one of the Corydalis extract powder and the Veratridine powder to prepare the composite insecticide in Comparative Examples 2 and 3 have worse aphid prevention effects than those prepared by using both the Corydalis extract powder and the Veratridine powder in Example 1. This shows that Corydalis extract and Veratridine have synergistic insecticidal effects, and when used in combination, they have better pest killing effects.

[0038] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A process for preparing a composite insecticide containing plant extracts, characterized in that: The steps include: S1: Preparation of composite carrier powder The nano calcium carbonate powder is dispersed in deionized water, and then added into a mixed solution of calcium nitrate solution and diammonium hydrogen phosphate solution to react to obtain a composite carrier powder; S2: Preparation of modified composite carrier powder The composite carrier powder is dispersed in toluene, and diphenyl chlorophosphate is added for activation, and then octadecanoyl chloride solution and dodecylamine are added in sequence for reaction to obtain a modified composite carrier powder; S3: Preparation of Corydalis extract extracting the Corydalis with an ethanol solution to obtain a Corydalis extract; S4: Preparation of compound insecticide The modified composite carrier powder is used to load the Corydalis extract, veratrine and matrine respectively, and then mixed with a dispersant, a wetting agent, a disintegrant and an aqueous binder solution for granulation to obtain a composite insecticide.

2. The preparation process of a composite insecticide containing plant extracts according to claim 1, characterized in that: S1 specifically includes the following steps: S1.1: Add nano calcium carbonate powder into deionized water at a solid-liquid ratio of 1 g: (20-30) mL, and ultrasonically disperse for 30-40 min to obtain a nano calcium carbonate dispersion; S1.2: Add calcium nitrate tetrahydrate and diammonium hydrogen phosphate into deionized water respectively, stir and dissolve thoroughly to prepare 0.5 mol / L calcium nitrate solution and 0.3 mol / L diammonium hydrogen phosphate solution; S1.3: Mix the calcium nitrate solution and the diammonium phosphate solution, add 5 wt % PEG-6000, and stir well to obtain a mixed solution; S1.4: Add the above nano calcium carbonate dispersion into the above mixed solution in a volume ratio of 1:(2-3), add 25% ammonia water dropwise to maintain the pH at 10.3-10.5, and stir the reaction for 2-3 hours to obtain a precursor solution; S1.5: The precursor solution is transferred to a high-pressure reactor, heated and stirred at 160-180°C for 8-10 hours, and after cooling, centrifugally washed and freeze-dried to obtain a composite carrier powder.

3. The preparation process of a composite insecticide containing plant extracts according to claim 2, characterized in that: S2 specifically includes the following steps: S2.1: Add the above composite carrier powder to toluene at a solid-liquid ratio of 1g: (15-25)mL, then add triethylamine, and after ultrasonic dispersion for 30-40min, add diphenyl chlorophosphate, and heat under reflux at 80-90°C for 6-8h to obtain an activated carrier dispersion; S2.2: Add octadecanoyl chloride to toluene at a solid-liquid ratio of 1 g: (10-12) mL, stir thoroughly, and prepare an octadecanoyl chloride solution; S2.3: Add the above-mentioned octadecanoyl chloride solution to the above-mentioned activated carrier dispersion in a volume ratio of 1:(3-5), heat and react at 70-80°C for 6-7h under nitrogen protection, then add dodecylamine, adjust the pH to 9-9.2 with 0.1mol / L sodium hydroxide solution, continue to heat and reflux at 70-80°C for 8-10h, filter, wash and dry to obtain a modified composite carrier powder.

4. The preparation process of a composite insecticide containing plant extracts according to claim 3, characterized in that: S3 specifically includes the following steps: S3.1: Clean and dry the fresh Corydalis, place in an oven at 45-50°C until it becomes brittle, and then crush and sieve through 80-120 mesh to obtain Corydalis powder; S3.2: Add the above-mentioned Corydalis powder to 90% ethanol solution at a solid-liquid ratio of 1g: (10-20)mL, ultrasonically treat at 100-200W for 20-30min, and then soak for 20-24h. After filtering, place the filtrate in a 55℃ rotary evaporator, pressurize and concentrate to a paste, and then freeze-dry to obtain the Corydalis extract.

5. The process for preparing a composite insecticide containing plant extracts according to claim 4, characterized in that: S4 specifically includes the following steps: S4.1: Add the Corydalis extract obtained in step S3.2 to 90% ethanol solution at a solid-liquid ratio of 1 g: (20-30) mL, stir for 20-30 min, and then ultrasonically disperse for 10-20 min, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1 g: (30-40) mL, ultrasonically load for 40-50 min, centrifugally filter, wash and dry to obtain Corydalis loaded powder; S4.2: Add veratridine to anhydrous ethanol at a solid-liquid ratio of 1 g: (20-30) mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1 g: (30-40) mL, ultrasonically load for 30-40 min, centrifuge, filter, wash and dry to obtain veratridine-loaded powder; S4.3: Add matrine to anhydrous ethanol at a solid-liquid ratio of 1 g: (90-100) mL, stir thoroughly to dissolve, then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1 g: (30-40) mL, ultrasonically load for 30-40 min, centrifuge, filter, wash and dry to obtain matrine-loaded powder; S4.4: Add the above-mentioned Corydalis powder, the above-mentioned Veratrine powder, the above-mentioned Matrine powder, dispersant, wetting agent and disintegrant into a mixer, mix them thoroughly and evenly, then add 20% by mass aqueous solution of binder, and perform extrusion granulation. After drying and sieving, a composite insecticide is obtained.

6. The preparation process of a composite insecticide containing plant extracts according to claim 2, characterized in that: The molar ratio of calcium in the calcium nitrate solution to phosphorus in the diammonium phosphate solution is 5:

3.

7. The process for preparing a composite insecticide containing plant extracts according to claim 3, characterized in that: In step S2.1, the volume ratio of triethylamine to toluene is 1:(38-42), and the volume ratio of diphenyl chlorophosphate to toluene is 1:(2.3-2.5).

8. The process for preparing a composite insecticide containing plant extracts according to claim 3, characterized in that: The molar ratio of dodecylamine to octadecanoyl chloride is 1:

2.

9. The process for preparing a composite insecticide containing plant extracts according to claim 5, characterized in that: The weight percentage of each component in the composite insecticide is: 10-20% of matrine-loaded powder, 5-6% of dispersant, 2-3% of wetting agent, 18-20% of disintegrant and 3-5% of adhesive, and the balance is corydalis-loaded powder and veratridine-loaded powder, and the mass ratio of corydalis-loaded powder to veratridine-loaded powder is (3.5-4.5):1; wherein the dispersant is lignin sulfonate; the wetting agent is sodium dodecyl sulfate; the disintegrant is any one of sodium sulfate, calcium sulfate, sodium bicarbonate, magnesium chloride and sodium chloride; and the adhesive is any one of starch, carboxymethyl cellulose, gelatin and carboxyethyl cellulose.

10. A composite insecticide containing plant extracts, characterized in that: The compound insecticide is prepared by the preparation process of a compound insecticide containing plant extracts as described in any one of claims 1 to 9.

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