Insecticides chlorine-containing

Halogen-containing substances e. g. chlorine-containing insecticides [1, 7] such as aldrin, dieldrin, DDT, perthane,... 

Organochloride. For the estimation of chlorine containing insecticides, the developed plate is sprayed with a 1.0% ethanolic silver nitrate solution containing five milliliters of concentrated ammonia solution. After drying the sprayed plate in air, it is irradiated with U.V. light (366 nm) for ten minutes. After exactly ten minutes, the area of the developed spots is measured and compared with that of the control insecticide run on the same TLC plate. 

As with all chemicals, the dose makes the poison. The chlorine-containing insecticide dichlorodiphenyltrichloroethane (DDT) is highly effective in killing disease-ridden mosquitoes, ticks, and fleas, but it is virtually nontoxic to mammals. The fluorine-containing pesticide 1080, or fluoroacetic add (FCH2CO2H), is highly toxic and often lethal to all mammals. The industrial and combustion by-product dioxin is highly toxic to some animals but not to others in humans, dioxin causes the skin disease chloracne. 

Abbott et al. [I] have undertaken an exhaustive investigation of the separation of 16 chlorine-containing insecticides. They used kiesel-guhr G, alumina 6 and mixed layers of silica gel G and alumina G (1 + 1) as well as the ordinary silica gel G. The huB/-values found in five of the 15 solvents tried out are given in Table 142 (Nos. Ill and X—XIII). Colour differentiation was obtained with a silver nitrate-bromophenol blue reagent. 

Methyl yellow-UY light for chlorine-containing insecticides. 

In one procedure that has been widely used, the sample, after suitable treatment, is refluxed with sodium and isopropyl alcohol, after which the solution is diluted with water and the inorganic chloride is determined by standard methods (13, 54) The method has been adopted by the Association of Official Agricultural Chemists 29, 30) as a tentative one for technical DDT and for dusts, oil solutions, and aqueous emulsions of DDT, for use in the absence of other chlorine-containing compounds. The National Association of Insecticide and Disinfectant Manufacturers has also accepted the total-chlorine method for the analysis of these preparations 28). Essentially the same procedures have been described by Donovan 22), of the Insecticide Division of the Production and Marketing Administration, for technical DDT and various commercial DDT products containing no other compounds interfering with the chlorine determination. 

If the sediment sample contains elemental sulphur, which hinders the determination of chlorinated organic insecticides, then this can be removed by a process involving treatment with concentrated sulphuric acid and tetrabutyl ammonium sulphate. 

Lindquist (34) and his associates have applied Diesel oil containing DDT or other chlorinated hydrocarbons as a prehatching treatment for controlling snow-water mosquitoes. Late in the fail Lindquist applied several oil formulations containing chlorinated hydrocarbon insecticides to swales and depressions that had produced mosquitoes in season. These oil formulations remained on the ground during the winter and when flooded with snow water proved toxic to the newly hatched mosquito larvae. A dosage of 2 pounds of DDT per acre (10 quarts of a 5% DDT-oil solution) prevented mosquito development in some instances for 2 years. 

There is need for experiments on the effect of various solvents in formulation of mosquito larvicides and adulticides containing chlorinated hydrocarbon insecticides. 

Another common misconception about the fate of chlorinated hydrocarbon insecticides in water is that they remain there forever. Like the soil, aquatic environments are dynamic systems. Residues of chlorinated hydrocarbons dissipate from aquatic environments by codistillation phenomena, metabolism, decomposition, and absorption on surfaces where they are subject to like dissipation forces. Table IV shows the loss of various insecticides by codistillation 20 hours after they were introduced into a jar of water containing mosquito larvae (2). This work was based on still systems. Recent work by investigators at Washington University... 

Hindin and co-workers (4) reported on a survey of the Columbia Basin river, ground, and irrigation water for chlorinated hydrocarbon insecticides and certain 2,4-D esters. Some of their samples contained aldrin and endrin in p.p.t. concentrations and less, but no dieldrin. 

Chlorinated hydrocarbon insecticides, which contain carbon, chlorine, and hydrogen, are also called organochlorine insecticides. Nearly all of these insecticides have been phased out of usage in the United States because of their long residual life, which causes environmental hazards. However, we will briefly study this group of insecticides to understand their historical significance. 

Cyclodienes are chlorinated hydrocarbon insecticides with a polycyclic structure and, as the name implies, two unsaturated bonds. Not all of the insecticides in this class meet these criteria. Chlordane, for example, contains only one double bond in its polycyclic structure. Endrin and dieldrin are epoxides of the cyclodienes isodrin and aldrin, respectively. 

Judgment and technical experience will enable an approximation of a unit consumption factor to be made in certain areas. The approximation will be nearer to the actuality, the more experienced the calculator is in the particular field. For instance, a man versed in the manufacture of chlorinated insecticides with knowledge of yields can calculate the unit consumption factor for chlorine consumption for an analogous new chlorine-containing product with fair accuracy. 

MAJOR USES Used in the manufacture of epoxy resins, glycerol, pharmaceuticals, agricultural chemicals, coatings, ion excheinge resins glycidyl esters insecticides textile chemicals adhesives plasticizers solvent for natural and synthetic resins, gums, cellulose esters and ethers, paints, varnishes and nail enamels and lacquers stabilizer in chlorine containing materials and an intermediate in the preparation of condensates with polyfiinctional substances. 

Organochlorine insecticides, such as DDT, aldrin, lindane, or chlordane — The term usually refers to a broad range of chlorine-containing organics used for pest control. No single structural feature... 

TABLE 3.11. Major Chlorine Containing Herbicides, Fungicides, and Insecticides with Regional Importance... 

In the past, a commercially important use of the Diels-Alder reaction involved the use of hexachlorocyclopentadiene as the diene. Depending on the dienophile, a variety of chlorine-containing addition products may be synthesized. Nearly all these products were powerful insecticides. Three insecticides synthesized by the Diels-Alder reaction are shown below. 

Indole and derivatives Insecticides —, chlorine-containing —, thiophosphate esters Iodine-containing compounds... 

Cyclodienes. These are polychlorinated cycHc hydrocarbons with endomethylene-bridged stmctures, prepared by the Diels-Alder diene reaction. The development of these insecticides resulted from the discovery in 1945 of chlordane, the chlorinated adduct of hexachlorocyclopentadiene and cyclopentadiene (qv). The addition of two Cl atoms across the double bond of the ftve-membered ring forms the two isomers of chlordane [12789-03-6] or l,2,4,5,6,7,8,8-octachloro-2,3,3t ,4,7,7t -hexahydro-4,7-methano-lJT-indene, QL-trans (mp 106.5°C) and pt-tis (32) (mp 104.5°C). The p-isomerhas signiftcantiy greater insecticidal activity. Technical chlordane is an amber Hquid (bp 175°C/267 Pa, vp 1.3 mPa at 25°C) which is soluble in water to about 9 fig/L. It has rat LD qS of 335, 430 (oral) and 840, 690 (dermal) mg/kg. Technical chlordane contains about 60% of the isomers and 10—20% of heptachlor. It has been used extensively as a soil insecticide for termite control and as a household insecticide. 

Chlorinated Terpenes. A group of incompletely characterized insecticidal compounds has been produced by the chlorination of the naturally occurring terpenes. Toxaphene [8001-35-2] is prepared by the chlorination of the bicycHc terpene, camphene [79-92-5] to contain 67—69% chlorine and has the empirical formula C QH QClg. The technical product is a yellowish, semicrystalline gum (mp 65—90°C, d 1.64) and is a mixture of 175 polychloro... 

Pesticides. Chlorinated hydrocarbon pesticides (qv) are often found in feed or water consumed by cows (19,20) subsequently, they may appear in the milk, where they are not permitted. Tests for pesticides are seldom carried out in the dairy plant, but are most often done in regulatory or private specialized laboratories. Examining milk for insecticide residues involves extraction of fat, because the insecticide is contained in the fat, partitioning with acetonitrile, cleanup (FlorisH [26686-77-1] column) and concentration, saponification if necessary, and determination by means of paper, thin-layer, microcoulometric gas, or electron capture gas chromatography (see Trace and residue analysis). 

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