Molecular Formula | C22H28O5 |
Molar Mass | 372.4547 |
Density | 1.12±0.1 g/cm3(Predicted) |
Boling Point | bp0.007 192-193° |
Specific Rotation(α) | D19 +14.7° (isooctane-ether) |
Solubility | Insoluble in water, easily soluble in organic solvents. |
Appearance | Light yellow oily viscous |
Storage Condition | 2-8℃ |
Refractive Index | nD20 1.5355 |
Use | Uses can be used for the production of aerosol insecticides, mosquito coils, animal shampoos and green pesticides |
Risk Codes | R20/21/22 - Harmful by inhalation, in contact with skin and if swallowed. R50/53 - Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. |
Safety Description | S13 - Keep away from food, drink and animal foodstuffs. S60 - This material and its container must be disposed of as hazardous waste. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. |
UN IDs | 2902 |
HS Code | 29183000 |
Hazard Class | 6.1(b) |
Packing Group | III |
synthetic route
The pyrethrum thousand flowers are crushed and passed through an 80-mesh sieve to facilitate more adequate absorption of microwave energy. Ten parts of dry pollen with known content after crushing (the average amount obtained by supercritical C02 extraction method and Shah extraction method is 1.69kg of pyrethrin per 100kg of dried flowers, I .e. the pyrethrin in dried pyrethrum flowers after crushing is 1.69%) and water content (5.03%) are taken and 100g each are placed in an open container respectively, and 30Oml of acetonitrile/hexane extraction solvent (medium constant 1.9, transparent to microwave, microwave irradiation extraction using power 625W, frequency 2450MHz, irradiation time 40s, filter residue, vacuum evaporation of ethylene/hexane extraction solvent, pyrethrin, acetonitrile/hexane can be reused.
analysis method
The content analysis method of pyrethrin in deinsecticide chrysanthemum or preparation has capacity analysis method, namely A.0.A.C method (mercury reduction method), colorimetric method, polarographic analysis method, color layer analysis method, paper chromatography method, spectral analysis method, etc.
1. gas chromatography: the six active components of pyrethrin can be separated by 10% NPGS Chromosorb W column and detected by electron capture detector at 160 ℃. If the temperature is programmed at 150~225 ℃,2 ℃/min and the hydrogen flame ionization detector is used for detection, the effect is better. It can also be analyzed by 3 ~ 5% SE-30 Chromosrb W column, gasification temperature 190 ℃, column temperature and detector temperature 205 ℃.
2. Thin layer chromatography and high performance liquid chromatography: On the silica gel HF-254 sheet, n-hexane/ethyl acetate (19:1) is used as the developing agent to separate 6 pyrethrin components. The separation and quantitative determination of 6 kinds of pyrethrins can be realized by using Lichrosorb Si-60 normal phase column, n-hexane/ethyl acetate (9:1) as mobile phase solvent, 1.5 ml/min, and ultraviolet detection at 254nm.
Pharmacokinetics
There are two main degradation pathways for pyrethrin, namely photodegradation and biodegradation. These two types of degradation are often carried out in overlap. When it enters the body of warm-blooded animals, it is degraded by the hydrolysis of the ester chain; when it is affected by sunlight and ultraviolet rays, it begins to degrade on the hydroxyl group, prompting its structure The acid and alcohol parts undergo oxidation, and the metabolism and excretion of pyrethrin in birds and mammals are much faster than in insects and fish. Its initial metabolism on plants is similar to that in livestock. The same forms of hydrolysis and oxidation of pyrethrin occurred in soil, but neither the degradation products nor the complete parent compounds were obtained by filtration.
environmental toxicology
allowable daily intake: 0.04 mg/kg.bw
acute oral LD50:2370mg/kg
acute percutaneous LD50:>5000mg/kg
China Toxicity: Low Toxicity
foreign toxicity:(Moderately hazardous, moderate hazard) LD50 rats (mg/kgbw) oral solid (50~500) liquid (200~2000), percutaneous solid (100~1000) liquid (400~4000)
aquatic organisms: highly toxic to fish, LC50(96 hours, mg/L, static test) silver salmon 39, canal catfish 114,LC50(μg/L) blue gill sunfish 10, rainbow trout 5.2
bees: highly toxic, anti-avoidance, LD50 (oral) 22ng/bee, (contact) 130-290ng/bee
natural enemies: acute oral LD50 wild duck> 10000mg/kg
Soil and water conservation: accelerated decomposition of sunlight and ultraviolet light
how to use
1. control of aphids: apply 5% pyrethrin emulsifiable concentrate 1000~1500 times in sunny evening or cloudy day, and apply evenly on the front and back of leaves and stems. When the population is large, the pesticide can be applied 2 times or more continuously, with an interval of 5~7 days each time.
2. prevention and control of Pieris rapae: 5% emulsifiable concentrate 1000~1500 times should be used before the third age of pests, and cabbage and cabbage should be used before the heart is wrapped. It should be sprayed evenly after the dew evaporates in the early morning.
3. control of whitefly and Bemisia tabaci: control of whitefly in the early stage of occurrence, control of whitefly before 9: 00 a.m. when the flying ability of whitefly is weak, and the medicine is diluted 000~1500 times. The stems and leaves are sprayed evenly, and the white whitefly gathering place on the back of the leaf is mainly sprayed. The pesticide is applied continuously for 2~3 times with an interval of 5~7 days each time.
4. prevention and control of leaf diving flies: spray the stems and leaves with 5% emulsifiable concentrate 1000~1500 times at the initial stage of leaf diving flies. the application should be uniform and thoughtful, and the application should be continuously applied 3 times or more, with an interval of 5~7 days each time.
5. prevention and control of cotton bollworm and tobacco worm: spray stems and leaves after dew evaporates in the early morning at the seedling stage of pepper and tomato with 5% pyrethrin emulsifiable concentrate 1000~1500 times; Application at flowering stage, application at about 9: 00 a.m. with emphasis on flower spraying; Application during fruit expansion period or picking period, spray prevention and control shall be carried out at dawn in the morning or after 7: 00 p.m, make the fruit completely drugged.
6. prevention and control of bean pod borer: spray stems and leaves of leguminous plants such as kidney bean and cowpea can be carried out at the seedling stage just after dew evaporates in the morning, about 9: 00 a.m. or after 5: 00 p.m.; Pests in flowering period shall be sprayed from 9: 00 a.m. to 10: 00 a.m. when flowers are in full bloom, with emphasis on spraying flowers. If conditions permit, spray can be carried out at about 7 o'clock in the evening after the sun goes down. The application should be meticulous and thoughtful, with emphasis on applying to pods.
Toxicity
symptoms of poisoning: pyrethrin is a nerve agent. the skin at the contact area feels tingling, especially around the mouth and nose but without erythema. It rarely causes systemic intoxication. When the amount of contact is large, it can cause headache, dizziness, nausea, vomiting, trembling of hands, convulsions or convulsions, coma, and shock.
emergency treatment: no special antidote, symptomatic treatment. The stomach can be lavaged when swallowed in large quantities. Can't induce vomiting.
precautions
⑴ pyrethrin is easy to decompose when exposed to light, and spraying time is best in the evening.
⑵ pyrethrin cannot be mixed with alkaline pesticides such as stone sulfur mixture, Bordeaux mixture, rosin mixture, etc.
(3) commercial preparations should be stored in closed containers to avoid high temperature, humidity and direct sunlight.
(4) pyrethrum is a powerful contact agent. when applying medicine, the agent must contact the worm body to be effective, otherwise the effect is not good.
production method
1. it exists in the flowers of several plants of chrysanthemum (Chrysanthemum), pyrethrum subgenus (Pyrethrum) in Compositae family, especially pyrethrum (Pyrethrum cinerariaefolium). Pyrethrum dried flowers contain pyrethrin generally 0.9% ~ 1.3%, which is extracted by petroleum ether reflux and concentrated to obtain a crude viscous substance containing about pyrethrin 30%, which is dewaxed and decolorized to obtain a high-quality product containing pyrethrin 60%, which can be used for preparing extract and processing other preparations. For example, nitromethane is used for further refining, and finally a colorless viscous oily high-purity product with a pyre. It can also be extracted with mixed solvents, such as methanol/kerosene, petroleum ether/acetonitrile, petroleum ether/nitromethane, etc.
toxic substance data | 121-29-9(Hazardous Substances Data) |
specific rotation | D19 14.7° (isooctane-ether) |
EPA chemical information | Pyrethrin II (121-29-9) |