Overview
The chemical name of Diazinon is O,O-diethyl-O-(2-isopropyl)-4-methyl-6-pyrimidinyl)thiophosphate, also known as Diazinon Diazinon is a broad-spectrum, high-efficiency organophosphorus insecticide and acaricide. Diazinon has low toxicity and has contact killing, stomach poisoning, fumigation and certain systemic effects. It has a good control effect on various pests such as Lepidoptera and Homoptera. It is mainly used in rice, cotton, fruit trees, vegetables, sugar cane, corn, tobacco, potatoes and other crops to control sucking mouthpart pests and food. In addition, diazinon is also widely used in the field of veterinary medicine and can also be used as an insecticide spray for household hygiene. It has broad application prospects.
Physical and chemical properties
The pure product is a colorless and odorless liquid with a boiling point of 83-84°C (0.0002mmHg), a vapor pressure of 7.3×10^(-7)mmHg, and a solubility in water of 40ppm at room temperature. It is unstable above 50°C. It decomposes above 120℃ and is easily oxidized; it is unstable to acid and alkali and stable to light. The industrial product is a transparent light auburn liquid.
Toxicity
According to my country’s pesticide toxicity classification standards, diphosphine is a poisonous pesticide. The acute oral LD50 of the original drug in rats is 285mg/kg, the dermal LD50 is 455mg/kg, and the acute inhalation LD50 in mice is 630mg/m3. It has a slight irritating effect on the skin and eyes of male rabbits and has no teratogenic, carcinogenic or mutagenic effects under test conditions.
Features
Diazinon is a broad-spectrum organophosphorus insecticide with contact killing, stomach poisoning, fumigation and certain systemic effects. Its mechanism of action is to inhibit acetylcholinesterase; It is better to prevent various pests such as worms and other pests, and it can also be used to control underground pests by dressing seeds.
Application scope
Diazinon can be used in cotton to control cotton aphid (active ingredient 20-30g/mu), cotton spider mite (active ingredient 30-40g/mu), cabbage caterpillar (active ingredient 20-25g/mu), vegetable aphid ( Active ingredients: 20-25g/mu), onion leafminer, bean fly (active ingredient: 20-25g/mu), rice borer, rice borer (active ingredient: 25-37g/mu), rice midge (Active ingredients 20-25g/mu), rice planthoppers, rice leafhoppers, rice leafminers (active ingredients 25-37g/mu), corn, wheat, peanut underground pests (active ingredients 20-250g/mu).
Detection level
Diazinon’s low water solubility (<100mg/L) and high n-octanol/water partition coefficient (logKow≥3) make it potentially ecologically enrichable and easy to remain in the environment . European and American countries have found in multiple surveys of pesticide concentration levels in water bodies that diazinon is one of the common pharmaceutical residue pollutants in water bodies. Diazinon was detected in the sediment of the Blue River, a lower tributary of the Missouri River, at a level of 2.6 ng/g. Diazinon is one of the 10 most common Tosoh substances that contaminate groundwater. The high concentration value of diazinon in groundwater appears after the pesticide application season (May to August) (the maximum concentration value reaches 0.023 μg/L from June to September), and the concentration decreases significantly in the subsequent autumn and winter seasons. (The maximum concentration is only 0.005μg/L). Changes in drug residue concentrations indicate that diazinon has a certain penetration potential and may affect deep water bodies. This study detected several pesticides such as diazinon in spring water, well water, and precipitation in agricultural areas of Imahia State, and the detection rate of diazinon and triazine metabolites (DEA) in precipitation It is higher than other pollutants, indicating that diazinon has certain mobility in the environment, which may be related to the polar groups contained in its molecular structure.
Biodegradability
Most of the diazinon phosphorus in water bodies and soil surfaces is removed through the process of photodegradation and hydrolysis, while the photolysis and hydrolysis rates of diazinon phosphorus adsorbed on solid sediments and deep groundwater are reduced, and biodegradation is especially aerobic conditions. Degradation under the environment becomes the main route of removal. 95% of the initial concentration of diazinon in the water body can be hydrolyzed and converted into the metabolite IMP within 2 days; under dark conditions, only 30% of the diazinon in the sterilized soil was degraded within 21 days; while in the In the experimental soil under environmental conditions, 90% of diazinon was degraded due to biodegradation. Pseudomonas sp. and Arthrobacter sp. can also utilize diazines as the sole carbon source. In addition, Arthrobacter sp. and Streptomycess sp. can remove diazinon through a cometabolism process. Organic carbon sources such as glucose and alcohols can accelerate the biodegradation process of diazinon. All three strains of degrading bacteria can use diazinon as the sole carbon source and can remove 8% to 92% of the initial concentration within 14 days. Adding glucose can accelerate degradation, but at the same time, the pH will decrease.
Preparation method
1. Synthesis of isobutyramidine hydrochloride. Add 53.5g of isobutyronitrile to a three-necked flask equipped with a reflux condenser, stirring device, thermometer, and gas introduction tube. Then, add anhydrous methanol under stirring, control the temperature, and introduce dry hydrogen chloride gas within 60 to 90 minutes. After passing the hydrogen chloride, add ice-cold methanol, react for another 1 hour, cool, control the temperature, and pass in dry ammonia. When the pH value of the reaction solution reaches 8 to 9, stop passing ammonia, continue the reaction for 1 to 3 hours, and filter to obtain 183.5g of filtrate. , the content of isobutamidine hydrochloride is 47.8%, and the yield is 93.6%.
2. Synthesis of hydroxypyrimidine. Add 0.25 mol of isobutylamidine hydrochloride solution into a 250 ml three-necked flask, heat to evaporate the methanol, dedry, add ethyl acetoacetate and solvent I, and add hydrogen at a certain temperature. Sodium oxide solution was then heated, refluxed and dehydrated for 2 hours, cooled, filtered, and the filter cake was acid washed, neutralized, and dried to obtain 34 g of solid hydroxypyrimidine, with a content of 97.98% and a cyclization yield of 87.6%.
3. Synthesis of diazinon. Add 34g of the hydroxypyrimidine synthesized above into a 250ml three-necked bottle, and add100ml of solvent II and a small amount of potassium carbonate and catalyst are heated and stirred to increase the temperature. Add ethyl chloride dropwise at a certain temperature. After the addition is completed, the reaction solution is kept warm for 2 hours. The reaction solution is washed with alkali, pickled, neutralized, layered, and organically layered. After desolvation under reduced pressure, 61.5g of diazinon crude oil was obtained, with a content of 97.4% and a condensation yield of 89.8%.
Figure 1 is the reaction equation for the synthesis of diazinon
Antioxidant 1010
Application
1.40% diazinon EC can be used as a foliar spray to control rice borers and pests on corn, vegetables and other crops. It has a long-lasting effect and is widely used. It is especially effective against flies.
Application of 2.10% diazinon granules
(1) Prevention and control of tobacco underground pests. The main underground pests that harm tobacco include grubs, cutworms, and crickets, causing tobacco pond shortages. When transplanting tobacco, 0.5-1g of 10% diazinon granules per plant can be used in the pond and then covered with soil and watered. This can give full play to its contact and fumigation effects and kill pests.
(2) Prevention and control of sugarcane underground pests. When planting sugarcane for the first time, after sowing, mix 2 kilograms of 10% diazinon granules with 5 kilograms of fine soil and sprinkle it into the planting ditch and then cover it with soil. This can effectively kill underground pests and protect the cane roots and cane buds from damage. Ratoon cane is combined with loose soil in the beginning of spring. During the germination period of cane buds, mix 10 kg of fine soil with 2-3 kg of 10% diazinon granules per mu, sprinkle it around the roots and then loosen the soil around the roots, so that the medicinal soil is buried around the roots. Play its role of contact and fumigation.
(3) Control mango root mealybug and apple phylloxera. When carrying out winter soil management for fruit-bearing trees. After digging the soil around the roots, mix 2-3 kg of 10% diazinon granules with 10 kg of fine soil. Apply 300-500 grams to each plant. Spread into the dug soil, and then dig once more. , turn the medicinal soil into the soil.
(4) Control yellow ants on marigold and other crops. In the cultivation of marigold and other crops, the harm caused by cricket ants in some areas is also very serious. You can use 1-2 kilograms of 10% diazinon granules per mu mixed with 5-10 kilograms of fine soil, and spread it after the marigolds and other crops are transplanted. Around the roots, then build up soil and water and cover with film.
Main reference materials
[1]Hu Zhongfu, Wu Jianwen, Yang Fashen, Song Shuiping, Dai Jiasheng, Dai Xufang. Research on the synthesis of diazinon [J]. Zhejiang Chemical Industry, 1999(01):19-20.
[2]Liu Weidong, Zhang Haibin. Research on continuous process of diazinon production[J]. Anhui Chemical Industry, 2006(05):30-31.
[3]Li Xiangdong. Diazinon Application Technology[J]. Rural Practical Technology, 2005(02):30.
[4]Wang Weiguo. Research on methods in the production process of diazinon [D]. Hunan University, 2005.
[5] Cui Xu. Research on the residual behavior of diazinon in Atractylodes and soil [D]. Zhejiang University, 2014.
[6] Lin Jinquan. Research progress on the environmental effects and remediation of diazinon [J]. Guangdong Chemical Industry, 2012, 39(06):165-166.
