A compound insecticide containing plant extracts and its preparation process

Abstract

The present invention provides a composite insecticide containing plant extracts and its preparation process, belonging to the technical field of pesticide preparation; the preparation process includes the following steps: preparing a composite carrier powder; preparing a modified composite carrier powder; preparing a Corydalis extract; preparing a composite insecticide. 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 carrying out a hydrothermal reaction to prepare a composite carrier powder of nano-calcium carbonate and hydroxyapatite, after loading the Corydalis extract and veratridine with this composite carrier powder, the prepared composite insecticide can have a slow-release effect, extend the insecticidal action time, reduce the number of pesticide applications, and reduce environmental pollution. In addition, after modifying the composite carrier powder, its loading rate for the Corydalis extract and veratridine can be improved, thereby enhancing the insecticidal effect of the composite insecticide.

Description

Technical Field

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

[0002] In agricultural production, the control of pests has always been a key link in ensuring crop yield and quality. Although traditional chemical insecticides have high and rapid insecticidal effects, long-term and large-scale use has led to many serious problems. For example, early widely used organochlorine insecticides, such as dichlorodiphenyltrichloroethane (DDT), although having significant insecticidal effects, have extremely stable chemical properties and are difficult to degrade in the environment, with a half-life of several years or even decades. This not only causes its continuous residues in soil and water bodies, accumulates continuously through the food chain, causes persistent and extensive damage to the ecosystem, seriously threatens human health, but also easily leads to a sharp increase in pest resistance, greatly reducing the control effect.

[0003] As a natural insecticidal resource, plant-derived insecticides have received extensive attention due to their environmental friendliness, diverse biological activities, low toxicity, and difficulty in generating resistance. However, the stability of plant extracts is poor and is easily decomposed by environmental factors such as light, temperature, and humidity, resulting in a decrease in the content of active ingredients and the difficulty in maintaining the insecticidal effect.

[0004] Therefore, it is necessary to propose a composite insecticide containing plant extracts with environmental friendliness and a persistent insecticidal effect and a preparation process thereof. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose 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 includes the following steps:

[0007] S1: Prepare composite carrier powder

[0008] Disperse nano-calcium carbonate powder in deionized water, and then add it to a mixed solution of calcium nitrate solution and diammonium hydrogen phosphate solution for reaction to obtain composite carrier powder;

[0009] S2: Prepare modified composite carrier powder

[0010] Disperse the above-mentioned composite carrier powder in toluene, add diphenyl chlorophosphate for activation, and then successively add stearoyl chloride solution and dodecylamine for reaction to obtain modified composite carrier powder;

[0011] S3: Prepare Corydalis extract

[0012] Extract Corydalis with an ethanol solution to obtain a Corydalis extract;

[0013] S4: Prepare a composite insecticide

[0014] Use the above-mentioned modified composite carrier powder to load the above-mentioned Corydalis extract, veratridine, and matrine respectively, and then mix and granulate with an aqueous solution of a dispersant, a wetting agent, a disintegrant, and a binder to obtain a composite insecticide.

[0015] Furthermore, S1 specifically includes the following steps:

[0016] S1.1: Add nano-calcium carbonate powder to deionized water according to a solid-liquid ratio of 1 g:(20 - 30) mL, and ultrasonically disperse for 30 - 40 min to obtain a nano-calcium carbonate dispersion;

[0017] S1.2: Add calcium nitrate tetrahydrate and diammonium hydrogen phosphate to deionized water respectively, stir well to dissolve, and prepare a 0.5 mol / L calcium nitrate solution and a 0.3 mol / L diammonium hydrogen phosphate solution;

[0018] S1.3: Mix the above-mentioned calcium nitrate solution with the above-mentioned diammonium hydrogen phosphate solution, and add 5 wt% PEG-6000, stir well to mix to obtain a mixed solution;

[0019] S1.4: Add the above-mentioned nano-calcium carbonate dispersion to the above-mentioned mixed solution according to a volume ratio of 1:(2 - 3), and during this period, add 25% ammonia water to maintain the pH at 10.3 - 10.5, and then stir and react for 2 - 3 h to obtain a precursor solution;

[0020] S1.5: Transfer the above-mentioned precursor solution to a high-pressure reaction kettle, heat and stir at 160 - 180 °C for 8 - 10 h, and after cooling, perform centrifugal washing and freeze-drying to obtain a composite carrier powder.

[0021] Furthermore, S2 specifically includes the following steps:

[0022] S2.1: Add the above-mentioned composite carrier powder to toluene according to a solid-liquid ratio of 1 g:(15 - 25) mL, then add triethylamine, ultrasonically disperse for 30 - 40 min, add diphenyl chlorophosphate, and heat and reflux at 80 - 90 °C for 6 - 8 h to obtain an activated carrier dispersion;

[0023] S2.2: Add stearoyl chloride to toluene according to a solid-liquid ratio of 1 g:(10 - 12) mL, stir well to make a homogeneous solution to prepare a stearoyl chloride solution;

[0024] S2.3: Add the above octadecanoyl chloride solution to the above activated carrier dispersion liquid at a volume ratio of 1:(3 - 5). Under nitrogen protection, heat and react at 70 - 80 °C for 6 - 7 h. Then add dodecylamine, adjust the pH to 9 - 9.2 with 0.1 mol / L sodium hydroxide solution, and continue to heat and reflux at 70 - 80 °C for 8 - 10 h. After filtration, washing, and drying, obtain the modified composite carrier powder.

[0025] Further, S3 specifically includes the following steps:

[0026] S3.1: Clean and dry the fresh Corydalis, place it in an oven at 45 - 50 °C and dry until brittle, then crush and sieve through 80 - 120 meshes to obtain Corydalis powder.

[0027] S3.2: Add the above Corydalis powder to a 90% ethanol solution at a solid-liquid ratio of 1 g:(10 - 20) mL, perform ultrasonic treatment at 100 - 200 W for 20 - 30 min, then soak for 20 - 24 h. After filtration, place the filtrate in a rotary evaporator at 55 °C, pressurize and concentrate to a paste, and then perform freeze-drying to obtain Corydalis extract.

[0028] Further, S4 specifically includes the following steps:

[0029] S4.1: Add the Corydalis extract prepared in step S3.2 to a 90% ethanol solution at a solid-liquid ratio of 1 g:(20 - 30) mL, stir for 20 - 30 min, then perform ultrasonic dispersion for 10 - 20 min. Then add the modified composite carrier powder prepared in step S2.3 at a solid-liquid ratio of 1 g:(30 - 40) mL, perform ultrasonic loading for 40 - 50 min, and after centrifugal filtration, washing, and drying, obtain the Corydalis-loaded powder.

[0030] S4.2: Add veratridine to absolute ethanol at a solid-liquid ratio of 1 g:(20 - 30) mL, stir thoroughly to dissolve, then add the modified composite carrier powder prepared in step S2.3 at a solid-liquid ratio of 1 g:(30 - 40) mL, perform ultrasonic loading for 30 - 40 min, and after centrifugal filtration, washing, and drying, obtain the veratridine-loaded powder.

[0031] S4.3: Add matrine to absolute ethanol at a solid-liquid ratio of 1 g:(90 - 100) mL, stir thoroughly to dissolve, then add the modified composite carrier powder prepared in step S2.3 at a solid-liquid ratio of 1 g:(30 - 40) mL, perform ultrasonic loading for 30 - 40 min, and after centrifugal filtration, washing, and drying, obtain the matrine-loaded powder.

[0032] S4.4: Add the above-mentioned corydalis powder carrier, the above-mentioned veratrine powder carrier, the above-mentioned matrine powder carrier, a dispersant, a wetting agent and a disintegrant into a mixer, mix them thoroughly and evenly, then add an aqueous binder solution with a mass fraction of 20%, and carry out extrusion granulation. After drying and screening, a compound insecticide is obtained.

[0033] Further, the molar ratio of calcium element in the calcium nitrate solution to phosphorus element in the ammonium dihydrogen phosphate solution is 5:3.

[0034] Further, 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).

[0035] Further, the molar ratio of dodecylamine to stearoyl chloride is 1:2.

[0036] Further, the weight percentage contents of each component in the compound insecticide are as follows: 10 - 20% matrine powder carrier, 5 - 6% dispersant, 2 - 3% wetting agent, 18 - 20% disintegrant and 3 - 5% binder, and the balance is corydalis powder carrier and veratrine powder carrier, and the mass ratio of corydalis powder carrier to veratrine powder carrier is (3.5 - 4.5):1; wherein, the dispersant is lignosulfonate; the wetting agent is sodium dodecyl sulfate; the disintegrant is any one of sodium sulfate, calcium sulfate, sodium bicarbonate, magnesium chloride and sodium chloride; the binder is any one of starch, carboxymethyl cellulose, gelatin and carboxyethyl cellulose.

[0037] Further, a compound insecticide containing plant extracts is prepared by the preparation process of a compound insecticide containing plant extracts described in any one of the above.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] 1. In the present invention, 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 carrying out a hydrothermal reaction to prepare a composite carrier powder of nano calcium carbonate and hydroxyapatite, after loading corydalis extract, veratrine and matrine with the composite carrier powder, not only can its stability be improved, but also the prepared compound insecticide can have a slow-release effect, prolong the insecticidal action time, reduce the number of pesticide applications, and reduce environmental pollution. In addition, after activating the composite carrier powder with diphenyl chlorophosphate, and then successively adding stearoyl chloride solution and dodecylamine to carry out reactions respectively, after modifying the composite carrier powder, its surface properties can be changed, its hydrophobicity can be enhanced, and further the interaction with corydalis extract and veratrine can be enhanced, so as to improve its loading rate of corydalis extract and veratrine, thereby enhancing the insecticidal effect of the compound insecticide.

[0040] 2. In the present invention, first, Corydalis is extracted with an ethanol solution to prepare a Corydalis extract, and then the Corydalis extract and veratridine are mixed to form 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 motor control of pests to enhance the insecticidal effect. On the other hand, the active ingredients of the Corydalis extract can inhibit the detoxifying enzymes in pests and delay their metabolism of veratridine, thereby prolonging its action time. In addition, the polar components in the Corydalis extract can damage the cuticular wax layer of insects and promote the penetration and absorption of veratridine. Therefore, the Corydalis extract and veratridine have a synergistic insecticidal effect, and when the two are combined and used, they have a better pest killing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings incorporated herein and constituting a part of the specification illustrate embodiments of the present disclosure and, together with the specification, are further used to explain the principles of the present disclosure and enable those skilled in the relevant art to implement and use the present disclosure.

[0042] Figure 1 It is a process flow diagram of the preparation of a composite insecticide containing a plant extract adopted in the embodiment of the present invention.

[0043] Figure 2 It is a cumulative release rate curve graph of the Corydalis extract powder and veratridine powder prepared in Example 1 of the present invention for 72 hours. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The following describes in detail a composite insecticide containing a plant extract and its preparation process provided by the present invention with reference to the drawings and specific embodiments.

[0045] Example 1

[0046] A preparation process of a composite insecticide containing a plant extract, as Figure 1 shown, includes the following steps:

[0047] S1: Prepare a composite carrier powder

[0048] S1.1: Add nano calcium carbonate powder to deionized water according to a solid-liquid ratio of 1 g: 20 mL, and ultrasonically disperse for 30 min to obtain a nano calcium carbonate dispersion;

[0049] S1.2: Add calcium nitrate tetrahydrate and diammonium hydrogen phosphate to deionized water respectively, stir well to dissolve, and prepare a 0.5 mol / L calcium nitrate solution and a 0.3 mol / L diammonium hydrogen phosphate solution;

[0050] S1.3: Mix the above calcium nitrate solution with the above diammonium hydrogen phosphate solution, and add 5 wt% PEG-6000. Stir well to obtain a mixed solution. Among them, the molar ratio of calcium element in the calcium nitrate solution to phosphorus element in the diammonium hydrogen phosphate solution is 5:3;

[0051] S1.4: Add the above nano-calcium carbonate dispersion liquid to the above mixed solution according to the volume ratio of 1:2. During this process, add 25% ammonia water to maintain the pH at 10.3, and then stir and react for 2 h to obtain a precursor solution;

[0052] S1.5: Transfer the above precursor solution to a high-pressure reaction kettle, heat and stir at 160 °C for 8 h. After cooling, perform centrifugal washing and freeze-drying to obtain a composite carrier powder;

[0053] S2: Prepare a modified composite carrier powder

[0054] S2.1: Add the above composite carrier powder to toluene according to the solid-liquid ratio of 1 g:15 mL, then add triethylamine. After ultrasonic dispersion for 30 min, add diphenyl chlorophosphate, and heat and reflux at 80 °C for 6 h to obtain an activated carrier dispersion liquid. Among them, the volume ratio of triethylamine to toluene is 1:38, and the volume ratio of diphenyl chlorophosphate to toluene is 1:2.3;

[0055] S2.2: Add octadecanoyl chloride to toluene according to the solid-liquid ratio of 1 g:10 mL, stir well to prepare an octadecanoyl chloride solution;

[0056] S2.3: Add the above octadecanoyl chloride solution to the above activated carrier dispersion liquid according to the volume ratio of 1:3. Under nitrogen protection, heat and react at 70 °C for 6 h, 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 h, and obtain a modified composite carrier powder after filtration, washing and drying. Among them, the molar ratio of dodecylamine to octadecanoyl chloride is 1:2;

[0057] S3: Prepare a Corydalis extract

[0058] S3.1: Wash the fresh Corydalis clean and dry it, place it in an oven at 45 °C and dry it until it becomes brittle, then crush and sieve it through 80 mesh to obtain Corydalis powder;

[0059] S3.2: Add the above Corydalis powder to 90% ethanol solution according to the solid-liquid ratio of 1 g:10 mL, perform ultrasonic treatment at 100 W for 20 min, then soak for 20 h. After filtration, place the filtrate in a rotary evaporator at 55 °C, pressurize and concentrate it to a paste, and then perform freeze-drying to obtain a Corydalis extract;

[0060] S4: Prepare a composite insecticide

[0061] S4.1: Add the Corydalis extract obtained in step S3.2 to a 90% ethanol solution at a solid-liquid ratio of 1 g: 20 mL, stir for 20 min, then ultrasonically disperse for 10 min. Then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1 g: 30 mL, and ultrasonically load for 40 min. After centrifugal filtration, washing, and drying, the Corydalis-loaded powder is obtained;

[0062] S4.2: Add veratridine to absolute ethanol at a solid-liquid ratio of 1 g: 10 mL, stir well to dissolve. Then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1: 30 mL, and ultrasonically load for 30 min. After centrifugal filtration, washing, and drying, the veratridine-loaded powder is obtained;

[0063] S4.3: Add matrine to absolute ethanol at a solid-liquid ratio of 1 g: 90 mL, stir well to dissolve. Then add the modified composite carrier powder obtained in step S2.3 at a solid-liquid ratio of 1 g: 30 mL, and ultrasonically load for 30 min. After centrifugal filtration, washing, and drying, the matrine-loaded powder is obtained;

[0064] S4.4: Add the above-mentioned Corydalis-loaded powder, the above-mentioned veratridine-loaded powder, the above-mentioned matrine-loaded powder, a dispersant, a wetting agent, and a disintegrant to a mixer, mix well. Then add an aqueous binder solution with a mass fraction of 20%, and perform extrusion granulation. After drying and screening, a composite insecticide is obtained. Among them, the weight percentage content of each component in the composite insecticide is: 10% matrine-loaded powder, 5% lignosulfonate dispersant, 2% sodium dodecyl sulfate wetting agent, 18% sodium sulfate, and 3% starch, 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: 1.

[0065] Example 2

[0066] A preparation process of a composite insecticide containing plant extracts, as Figure 1 shown, includes the following steps:

[0067] S1: Prepare a composite carrier powder

[0068] S1.1: Add nano-calcium carbonate powder to deionized water at a solid-liquid ratio of 1 g: 25 mL, and ultrasonically disperse for 35 min to obtain a nano-calcium carbonate dispersion;

[0069] S1.2: Add calcium nitrate tetrahydrate and diammonium hydrogen phosphate to deionized water respectively, stir well to dissolve, and prepare a 0.5 mol / L calcium nitrate solution and a 0.3 mol / L diammonium hydrogen phosphate solution;

[0070] S1.3: Mix the above calcium nitrate solution with the above diammonium hydrogen phosphate solution, add 5 wt% PEG-6000, and stir well to obtain a mixed solution. Among them, the molar ratio of calcium element in the calcium nitrate solution to phosphorus element in the diammonium hydrogen phosphate solution is 5:3;

[0071] S1.4: Add the above nano-calcium carbonate dispersion to the above mixed solution according to a volume ratio of 1:2.5. During this process, add 25% ammonia water to maintain the pH at 10.4, and then stir and react for 2.5 h to obtain a precursor solution;

[0072] S1.5: Transfer the above precursor solution to a high-pressure reactor, heat and stir at 170 °C for 9 h. After cooling, carry out centrifugal washing and freeze-drying to obtain a composite carrier powder;

[0073] S2: Prepare the modified composite carrier powder

[0074] S2.1: Add the above composite carrier powder to toluene according to a solid-liquid ratio of 1 g:20 mL, then add triethylamine, ultrasonically disperse for 35 min, add diphenyl chlorophosphate, and heat under reflux at 85 °C for 7 h to obtain an activated carrier dispersion. Among them, the volume ratio of triethylamine to toluene is 1:40, and the volume ratio of diphenyl chlorophosphate to toluene is 1:2.4;

[0075] S2.2: Add octadecanoyl chloride to toluene according to a solid-liquid ratio of 1 g:11 mL, stir well to prepare an octadecanoyl chloride solution;

[0076] S2.3: Add the above octadecanoyl chloride solution to the above activated carrier dispersion according to a volume ratio of 1:4. Under nitrogen protection, heat and react at 75 °C for 6.5 h, 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 h, and after filtration, washing and drying, obtain the modified composite carrier powder. Among them, the molar ratio of dodecylamine to octadecanoyl chloride is 1:2;

[0077] S3: Prepare the extract of Corydalis

[0078] S3.1: Wash the fresh Corydalis clean and dry it, place it in an oven at 45 °C and dry it until it becomes brittle, then crush it and sieve it through a 100-mesh sieve to obtain Corydalis powder;

[0079] S3.2: Add the above Corydalis powder to 90% ethanol solution according to a solid-liquid ratio of 1 g:15 mL, ultrasonically treat it at 150 W for 25 min, then soak it for 22 h. After filtration, place the filtrate in a rotary evaporator at 55 °C, pressurize and concentrate it to a paste, and then carry out freeze-drying to obtain the extract of Corydalis;

[0080] S4: Prepare the composite insecticide

[0081] S4.1: Add the corydalis extract prepared in step S3.2 into a 90% ethanol solution at a solid-liquid ratio of 1 g: 25 mL, stir for 25 min, then ultrasonically disperse for 15 min. Then add the modified composite carrier powder prepared in step S2.3 at a solid-liquid ratio of 1 g: 35 mL, and ultrasonically load for 45 min. After centrifugal filtration, washing, and drying, the corydalis-loaded powder is obtained;

[0082] S4.2: Add veratridine into absolute ethanol at a solid-liquid ratio of 1 g: 15 mL, stir well to dissolve. Then add the modified composite carrier powder prepared in step S2.3 at a solid-liquid ratio of 1: 35 mL, and ultrasonically load for 35 min. After centrifugal filtration, washing, and drying, the veratridine-loaded powder is obtained;

[0083] S4.3: Add matrine into absolute ethanol at a solid-liquid ratio of 1 g: 95 mL, stir well to dissolve. Then add the modified composite carrier powder prepared in step S2.3 at a solid-liquid ratio of 1 g: 35 mL, and ultrasonically load for 35 min. After centrifugal filtration, washing, and drying, the matrine-loaded powder is obtained;

[0084] S4.4: Add the above-mentioned corydalis-loaded powder, the above-mentioned veratridine-loaded powder, the above-mentioned matrine-loaded powder, a dispersant, a wetting agent, and a disintegrant into a mixer, mix well. Then add an aqueous binder solution with a mass fraction of 20%, and perform extrusion granulation. After drying and screening, a composite insecticide is obtained. Among them, the weight percentage content of each component in the composite insecticide is: 15% matrine-loaded powder, 5.5% lignosulfonate dispersant, 2.5% sodium dodecyl sulfate wetting agent, 19% calcium sulfate, and 4% carboxymethyl cellulose, and the balance is corydalis-loaded powder and veratridine-loaded powder, and the mass ratio of corydalis-loaded powder to veratridine-loaded powder is 4:1.

[0085] Example 3

[0086] A preparation process of a composite insecticide containing plant extracts, as Figure 1 shown, includes the following steps:

[0087] S1: Prepare the composite carrier powder

[0088] S1.1: Add nano-calcium carbonate powder into deionized water at a solid-liquid ratio of 1 g: 30 mL, and ultrasonically disperse for 40 min to obtain a nano-calcium carbonate dispersion;

[0089] S1.2: Add calcium nitrate tetrahydrate and diammonium hydrogen phosphate into deionized water respectively, stir well to dissolve, and prepare a 0.5 mol / L calcium nitrate solution and a 0.3 mol / L diammonium hydrogen phosphate solution;

[0090] S1.3: Mix the above calcium nitrate solution with the above diammonium hydrogen phosphate solution, and add 5 wt% PEG-6000. Stir well to obtain a mixed solution. Among them, the molar ratio of calcium element in the calcium nitrate solution to phosphorus element in the diammonium hydrogen phosphate solution is 5:3;

[0091] S1.4: Add the above nano-calcium carbonate dispersion to the above mixed solution according to the volume ratio of 1:3. During this process, add 25% ammonia water to maintain the pH at 10.5, and then stir and react for 3 h to obtain a precursor solution;

[0092] S1.5: Transfer the above precursor solution to a high-pressure reaction kettle, heat and stir at 180 °C for 10 h. After cooling, perform centrifugal washing and freeze-drying to obtain a composite carrier powder;

[0093] S2: Prepare a modified composite carrier powder

[0094] S2.1: Add the above composite carrier powder to toluene according to the solid-liquid ratio of 1 g: 25 mL, then add triethylamine. After ultrasonic dispersion for 40 min, add diphenyl chlorophosphate and reflux at 90 °C for 8 h to obtain an activated carrier dispersion. Among them, the volume ratio of triethylamine to toluene is 1:42, and the volume ratio of diphenyl chlorophosphate to toluene is 1:2.5;

[0095] S2.2: Add stearoyl chloride to toluene according to the solid-liquid ratio of 1 g: 12 mL, stir well to prepare a stearoyl chloride solution;

[0096] S2.3: Add the above stearoyl chloride solution to the above activated carrier dispersion according to the volume ratio of 1:5. Under nitrogen protection, heat and react at 80 °C for 7 h, then add dodecylamine, adjust the pH to 9.2 with 0.1 mol / L sodium hydroxide solution, and continue to heat and reflux at 80 °C for 10 h. After filtration, washing and drying, obtain a modified composite carrier powder. Among them, the molar ratio of dodecylamine to stearoyl chloride is 1:2;

[0097] S3: Prepare a Corydalis extract

[0098] S3.1: Wash the fresh Corydalis clean and dry it, then place it in an oven at 50 °C and dry it until it becomes brittle. Then crush it and sieve it through 80-120 mesh to obtain Corydalis powder;

[0099] S3.2: Add the above Corydalis powder to a 90% ethanol solution according to the solid-liquid ratio of 1 g: 20 mL, perform ultrasonic treatment at 200 W for 30 min, then soak for 24 h. After filtration, place the filtrate in a rotary evaporator at 55 °C, pressurize and concentrate it to a paste, and then perform freeze-drying to obtain a Corydalis extract;

[0100] S4: Prepare a composite insecticide

[0101] S4.1: Add the corydalis extract prepared in step S3.2 into a 90% ethanol solution at a solid-liquid ratio of 1 g: 30 mL, stir for 30 min, then ultrasonically disperse for 20 min. Then add the modified composite carrier powder prepared in step S2.3 at a solid-liquid ratio of 1 g: 40 mL, and ultrasonically load for 50 min. After centrifugal filtration, washing and drying, the corydalis-loaded powder is obtained;

[0102] S4.2: Add veratridine into absolute ethanol at a solid-liquid ratio of 1 g: 20 mL, stir thoroughly to dissolve. Then add the modified composite carrier powder prepared in step S2.3 at a solid-liquid ratio of 1: 40 mL, and ultrasonically load for 40 min. After centrifugal filtration, washing and drying, the veratridine-loaded powder is obtained;

[0103] S4.3: Add matrine into absolute ethanol at a solid-liquid ratio of 1 g: 100 mL, stir thoroughly to dissolve. Then add the modified composite carrier powder prepared in step S2.3 at a solid-liquid ratio of 1 g: 40 mL, and ultrasonically load for 40 min. After centrifugal filtration, washing and drying, the matrine-loaded powder is obtained;

[0104] S4.4: Add the above-mentioned corydalis-loaded powder, the above-mentioned veratridine-loaded powder, the above-mentioned matrine-loaded powder, a dispersant, a wetting agent and a disintegrant into a mixer, mix thoroughly. Then add an aqueous binder solution with a mass fraction of 20% and carry out extrusion granulation. After drying and screening, a composite insecticide is obtained. Among them, the weight percentage content of each component in the composite insecticide is: 20% matrine-loaded powder, 6% lignosulfonate dispersant, 3% sodium dodecyl sulfate wetting agent, 20% sodium bicarbonate and 5% gelatin, and the balance is corydalis-loaded powder and veratridine-loaded powder, and the mass ratio of corydalis-loaded powder to veratridine-loaded powder is 4.5: 1.

[0105] Comparative Example 1

[0106] The difference between this 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 with an equal amount of the composite carrier powder prepared in step S1.5.

[0107] Comparative Example 2

[0108] The difference between this Comparative Example 2 and Example 1 is that the veratridine-loaded powder in step S4.3 is replaced with an equal amount of corydalis-loaded powder.

[0109] Comparative Example 3

[0110] The difference between this Comparative Example 3 and Example 1 is that the corydalis-loaded powder in step S4.3 is replaced with an equal amount of veratridine-loaded powder.

[0111] Test Example

[0112] Test 1: Weigh 10 mg of the prepared Corydalis powder and Veratrine powder in Example 1 respectively and put them into a conical flask containing 50 mL of release medium (volume ratio of anhydrous ethanol to deionized water = 3:1), simulate the release behavior at 25 °C, transfer 3 mL of the release medium at 2 h, 4 h, 8 h, 12 h, 24 h, 48 h, and 72 h respectively, detect the absorbance, supplement 3 mL of blank release medium, and then calculate and plot the cumulative release rate curve, as Figure 2 shown.

[0113] As Figure 2 can be seen, the cumulative release rates of the prepared Corydalis powder and Veratrine powder in Example 1 are both about 95% at 72 h, showing a sustained-release effect. That is to say, 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 carrying out a hydrothermal reaction to prepare a composite carrier powder of nano-calcium carbonate and hydroxyapatite, after loading the Corydalis extract and Veratrine with this composite carrier powder, not only can its stability be improved, but also the prepared composite insecticide can have a sustained-release effect, extend the insecticidal action time, reduce the number of pesticide applications, and reduce environmental pollution.

[0114] Test 2: Use high-performance liquid chromatography to detect the mass concentrations of Corydalis extract, Veratrine, and Matrine in the filtrate after centrifugal filtration and ultrasonic loading in steps S4.1 - S4.3 of Examples 1 - 3 and Comparative Example 1. The calculation formula for the loading rate is as follows:

[0115] Loading rate (%) = [Initial mass of Corydalis extract (or Veratrine / Matrine) - Mass concentration of Corydalis extract (or Veratrine / Matrine) in the filtrate × Volume of the filtrate] / Initial mass of Corydalis extract (or Veratrine / Matrine) × 100%. Each group was carried out with three parallel experiments, and the average value was taken. The results are shown in Table 1.

[0116] Table 1: Test results of the loading rates of Corydalis extract and Veratrine

[0117]

[0118] As can be seen from Table 1, after the composite carrier powder in Comparative Example 1 was not modified, the loading rates of the composite carrier powder for Corydalis extract, Veratrine, and Matrine were much lower than those in Example 1. Thus, it can be seen that after activating the composite carrier powder with diphenyl chlorophosphate and then successively adding octadecanoyl chloride solution and dodecylamine for reaction to modify the composite carrier powder, its loading rates for Corydalis extract, Veratrine, and Matrine can be improved, thereby enhancing the insecticidal effect of the composite insecticide.

[0119] Test 3: Aphid control effect test of the composite insecticide

[0120] Test method: Using a 100m 2 cotton experimental field with uniform soil quality, gentle terrain, and excellent irrigation and drainage as the test site, randomly divided into 5 groups, namely Example 1 group, Example 2 group, Example 3 group, Comparative Example 2 group, and Comparative Example 3 group, with each group being 20m 2 , and an electric sprayer was used for drug spraying to control aphids. During the drug application period, conventional cotton field management methods were used for management.

[0121] Drug application situation: The composite insecticides prepared in Examples 1 - 3 and Comparative Examples 2 - 3 were sprayed on the Example 1 - 3 groups and Comparative Example 2 - 3 groups respectively. The dosage was 30g / mu, and the spray was diluted with 30kg of water per mu.

[0122] Statistical method: Before drug application, 1 day, 3 days, and 15 days after drug application, the five - point sampling method was used to count the number of aphids, and the average value was taken. The reduction rate of the insect population was calculated according to the following formula:

[0123] Reduction rate of insect population (%) = (number of live insects before drug application - number of live insects after drug application) / number of live insects before drug application × 100%. The results are shown in Table 2.

[0124] Table 2: Aphid control effect of the composite insecticide

[0125]

[0126] As can be seen from Table 2, when preparing the composite insecticide using only one of the powder of Corydalis extract and the powder of veratrine in Comparative Example 2 and Comparative Example 3, the aphid control effect of the prepared composite insecticide is worse than that in Example 1 where both the powder of Corydalis extract and the powder of veratrine are used. Thus, it can be seen that Corydalis extract and veratrine have a synergistic insecticidal effect, and when the two are used in combination, a better pest killing effect can be achieved.

[0127] The above embodiments merely illustrate the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should 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 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, 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: (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 octadecanoyl chloride solution to the activated carrier dispersion in a volume ratio of 1:(3-5), heat at 70-80°C for 6-7h under nitrogen protection, then add dodecylamine, adjust the pH to 9-9.2 with 0.1 mol / L sodium hydroxide solution, continue to heat at 70-80°C for 8-10h, filter, wash and dry to obtain a modified composite carrier powder; S3: Preparation of Corydalis extract 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 1 g: (10-20) mL, treat with ultrasound at 100-200 W for 20-30 min, soak for 20-24 h, filter, place the filtrate in a rotary evaporator at 55 °C, pressurize and concentrate to a paste, and then freeze-dry 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: 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.

3. The preparation process of a composite insecticide containing plant extracts according to claim 1, characterized in that: The molar ratio of calcium in the calcium nitrate solution to phosphorus in the diammonium phosphate solution is 5:

3.

4. The preparation process of a composite insecticide containing plant extracts according to claim 1, 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).

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

2.

6. The preparation process of a composite insecticide containing plant extracts according to claim 2, 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.

7. 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 6.

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