Dichlorvos Dichlorvos
Structural formula
| Business number | 01CK |
|---|---|
| Molecular formula | C4H7Cl2O4P |
| Molecular weight | 220.98 |
| label |
Dimethyldichlorovinyl phosphate, Dimethyl dichlorovinyl phosphate, Atgard, Brevinyl, Chlorvinphos, Dichlorman, Dichlorophos, Equigard, Equigel, Estrosel, DDVP, Organophosphorus pesticides |
Numbering system
CAS number:62-73-7
MDL number:MFCD00036123
EINECS number:200-547-7
RTECS number:TC0350000
BRN number:1709141
PubChem number:24868911
Physical property data
1. Properties: The pure product is a colorless liquid with an aromatic odor. Volatile. [1]
2. Melting point (℃): <25[2]
3. Boiling point (℃): 140 (2.6kPa) [3]
4. Relative density (water = 1): 1.425 (25℃) [4]
5. Relative vapor density (air=1): 7.5[5]
6. Saturated vapor pressure (kPa): 0.001 (20℃) [6]
7. Octanol/water partition coefficient: 1.43[7]
8. Flash point (℃): 79.4 [8]
9. Solubility: Slightly soluble in water, easily soluble in most organic solvents such as ethanol and aromatic hydrocarbons. [9]
Toxicological data
1. Acute toxicity[10]
LD50: 50~80mg/kg (rat oral); 113mg/kg (large Rat transdermal)
LC50: 15mg/m3 (rat inhalation, 4h)
2. Irritation Temporary No data
3. Subacute and chronic toxicity [11] When the oral dose in rabbits is above 0.2 mg/(kg·d), At 24 weeks, it caused chronic poisoning, exceeding 1 mg/(kg·d), serious lesions occurred in the liver and kidneys of animals, and ChE continued to decline.
4. Mutagenicity [12] Microbial mutagenicity: Salmonella typhimurium 330μg/dish. DNA suppression: human lymphocytes 100μl. Sperm morphological changes: 35mg/kg in mouse abdominal cavity (5d).
5. Teratogenicity [13] The lowest toxic dose (TDLo) of 255 mg/kg administered orally to pigs 41 to 70 days after pregnancy will cause CNS Developmental malformations of the nervous system, blood and lymphatic systems (including spleen and bone marrow), and endocrine systems. Rats were given the lowest toxic dose (TDLo) of 15 mg/kg intraperitoneally on the 11th day after pregnancy, causing body wall developmental malformations.
6. Carcinogenicity [14] IARC Carcinogenicity Comment: G2B, suspected human carcinogen. The lowest oral toxic dose in rats (TDLo): 4120 mg/kg (2a, continuous), causes cancer, lung tumors, and gastrointestinal tumors. Transdermal lowest toxic dose in mice (TDLo)���20600mg/kg (2a, continuous), carcinogenic, gastrointestinal tumors.
7. Others[15] The lowest oral toxic dose in rats (TDLo): 39.2mg/kg (gestation 14~21d), causing Biochemical and metabolic changes in neonatal rats.
Ecological data
1. Ecotoxicity[16]
LC50: 1250ppb/96 (Atlantic silverfish, static); 1000ppm/24h (blue gill sunfish)
EC50: 0.00007mg/L (48h) (water flea)
2. Biodegradability No information yet
3. Non-biodegradability[17] In the air, when the concentration of hydroxyl radicals is 5.00×105pcs/cm3, the degradation half-life is 7.25h.
4. Other harmful effects[18] This substance is harmful to the environment and can cause pollution to water bodies and the atmosphere. , special attention should be paid to fish, bees and birds. Special attention should also be paid to vegetables, soil and water organisms.
Molecular structure data
1. Molar refractive index: 42.28
2. Molar volume (cm3/mol): 153.9
3. Isotonic specific volume (90.2K ): 382.6
4. Surface tension (dyne/cm): 38.1
5. Polarizability (10-24cm3): 16.76
Compute chemical data
1. Reference value for hydrophobic parameter calculation (XlogP): None
2. Number of hydrogen bond donors: 0
3. Number of hydrogen bond acceptors: 4
4. Number of rotatable chemical bonds: 4
5. Number of tautomers: none
6. Topological molecule polar surface area 44.8
7. Number of heavy atoms: 11
8. Surface charge: 0
9. Complexity: 181
10. Number of isotope atoms: 0
11. Determine the number of atomic stereocenters: 0
12. Uncertain number of atomic stereocenters: 0
13. Determine the number of chemical bond stereocenters: 0
14. Number of uncertain chemical bond stereocenters: 0
15. Number of covalent bond units: 1
Properties and stability
1. It is stable to heat, but can be hydrolyzed. A saturated aqueous solution decomposes 3% in 24 hours at room temperature, and can be completely hydrolyzed in an alkaline solution or boiling water for 1 hour. The hydrolysis products are dimethyl hydrogen phosphate and dichloroacetaldehyde.
2. Stability[19] Stable
3. Incompatible substances[20] Strong oxidizing agent, strong alkali
4. Conditions to avoid contact[21] Heating
5. Polymerization hazard[22] No polymerization
6. Decomposition products[23] Hydrogen chloride, phosphorus oxide
Storage method
Storage Precautions[24] Store in a cool, ventilated warehouse. Keep away from fire and heat sources. Keep container tightly sealed. They should be stored separately from oxidants, alkalis, and food chemicals, and avoid mixed storage. Equipped with the appropriate variety and quantity of fire equipment. The storage area should be equipped with emergency release equipment and suitable containment materials.
Synthesis method
1. Prepared by alkaline hydrolysis of trichlorfon in solvent.
2. Prepared by Perkoff rearrangement condensation of trimethyl phosphite and trichloroacetaldehyde.
3. It is prepared by alkaline hydrolysis of trichlorfon in a solvent. After the reaction is completed, the oil layer is left to stand for stratification. The oil layer is evaporated through thin film to recover the solvent and obtain dichlorvos crude oil. Or it can be obtained by the Perkow rearrangement condensation of trimethyl phosphite and trichloroacetaldehyde.
4. Dehydrochlorination method: Trichlorfon is dehydrochlorinated under alkaline conditions to generate dichlorvos. During operation, control the trichlorfon water suspension content to 25% (you can also use refined trichlorfon mother liquor and add an appropriate amount of trichlorfon solid). The ratio of trichlorfon to alkali is 1: (1.35~1.4). Use water and toluene (xylene, benzene) as two solvents, the reaction temperature is 50-60°C, the reaction time is 20-25 minutes, and the end-point pH value is 7-8. This reaction rearranges the α-hydroxyphosphonate into a phosphate ester. After the reaction is completed, the oil layer is allowed to stand and separate into layers. The oil layer is evaporated through thin film to recover the solvent and obtain dichlorvos crude oil.
5. Preparation or source: Under stirring, add molten trichlorfon and water to the alkaline hydrolysis kettle, add solvent benzene, and then add 30% liquid caustic soda, within about 2 to 3 minutes After the addition is completed, the temperature should not exceed 65°C. Control the pH value. If it is acidic, add alkali. After the addition, stir for 0.5 hours. Send the reactants to the liquid separator and let it stand for 15 to 30 minutes. Separate the water layer and let the benzene layer stand again. Leave for 15 minutes and further separate the water. The resulting dichlorvos benzene oil is heated under reduced pressure and flows through a thin film evaporator to remove benzene and water to obtain crude oil. It can also be produced by the Perkoff rearrangement condensation of trimethyl phosphite and trichloroacetaldehyde. Trimethyl phosphite is produced by the reaction of phosphorus trichloride and methanol. Preparations include: crude oil, 50%, 80% emulsifiable concentrate, 50% oil, 20% plastic block sustained-release agent, 15% sustained-release granules.
Remarks: The remaining validity period is short. Saturated dichlorvos aqueous solution is converted into dimethyl hydrogen phosphate and dichloroacetaldehyde. Its hydrolysis rate is about 3% per day, and it is hydrolyzed faster in alkaline solution. It is corrosive to iron and mild steel, but non-corrosive to stainless steel, aluminum, nickel, Hastelloy13 and Teflon. Stable to heat. The acute oral toxicity LD50 of male and female rats are 80 and 56 mg/kg respectively, and the acute dermal toxicity LD50 of male and female rats are 107 and 75 mg/kg respectively. Carp LC50 is 4mg/L. The allowable residue levels in rice, wheat, cereals, fruits, vegetables, and tea are 0.1 mg/kg, and those in strawberries are 0.3 mg/kg. ADI is 0.03mg/kg.
Purpose
1. An organophosphorus pesticide. It has fumigation, stomach poisoning and contact killing effects, and has good control effects on chewing mouthparts pests (such as aphids, red spiders, etc.) and piercing and sucking mouthparts pests (such as cabbage caterpillars, yellow-striped flea beetles, etc.). Used to control cotton aphids, beet leaf springtails, cherry fruit flies, and hygiene pests. Melons, willows, etc. are relatively sensitive. When using, add water at least 500 times. Sorghum and roses are susceptible to phytotoxicity and should not be used. Oil agents should not be sprayed on sorghum, soybeans, or melon crops. For home use, the dosage per standard room should not exceed 2ml.
2. Used as pesticides and fumigants. [25]
�The allowable residue level is 0.1mg/kg and 0.3mg/kg for strawberries. ADI is 0.03mg/kg.
Purpose
1. An organophosphorus pesticide. It has fumigation, stomach poisoning and contact killing effects, and has good control effects on chewing mouthparts pests (such as aphids, red spiders, etc.) and piercing and sucking mouthparts pests (such as cabbage caterpillars, yellow-striped flea beetles, etc.). Used to control cotton aphids, beet leaf springtails, cherry fruit flies, and hygiene pests. Melons, willows, etc. are relatively sensitive. When using, add water at least 500 times. Sorghum and roses are susceptible to phytotoxicity and should not be used. Oil agents should not be sprayed on sorghum, soybeans, or melon crops. For home use, the dosage per standard room should not exceed 2ml.
2. Used as pesticides and fumigants. [25]