Chlorine insecticides

Aldrin, a chlorinated insecticide now banned for use in the United States, can be made by Diels-Alder reaction of hexachloro-l,3-cyclopentadiene with norbomadicne. What is the structure of aldrin ... 

WEB DDT (dichlorodiphenyltrichloroethane) was the first chlorinated insecticide developed. It was used extensively in World War II to eradicate the mosquitoes that spread malaria. Its use was banned in the United States in 1978 because of environmental concerns. DDT is made up of carbon, hydrogen, and chlorine atoms. When a 5.000-g sample of DDT is burned in oxygen, 8.692 g of C02 and 1.142 g of H20 are obtained. A second five-gram sample yields 2.571 g of HC1. What is the simplest formula for DDT ... 

Sawicki and Elliott (31) re-examined the insecticidal activity of pyrethrin extracts and its four insecticidal constituents against four strains of houseflies, and checked the relative toxicity of pyrethrins I and II. This work confirmed the earlier results, showing that pyrethrin II was 1.3 to 1.6 times more toxic than pyrethrin I, but that the relative toxicities of pyrethrins I and II against the four strains of flies differed little. Resistance to knockdown but not to killing was associated in these strains with resistance to organophos-phorus and chlorinated insecticides. 

Mental disturbances, manifested as psychiatric sequelae, have been reported after exposure to organo-phosphates, including methyl parathion. Neuropsychiatric symptoms occurred in two aerial applicators, one of whom used methyl parathion as well as other insecticides, including chlorinated insecticides. One of these pilots had high levels of exposure to methyl parathion, toxaphene, and Dipterex with saturation of his clothing when the tank of his aircraft accidentally overflowed (Dille and Smith 1964). Several... 

Dale WE, Curley A, Cueto C. 1966. Hexane extractable chlorinated insecticides in human blood. Life Sci 5 47-54. 

Bowman MC, Schechter MS, Carter RL. 1965. Behavior of chlorinated insecticides in a broad spectrum of soil types. J Agric Food Chem 13 360-365. 

Dorough HW, Gibson JR. 1972. Chlorinated insecticide residues in cigarettes purchased in 1970-72. Environ Entomol 1 739-743. 

Brooks, G.T. (1974). The Chlorinated Insecticides, Vols 1 and 2—A detailed and authoritative standard reference work on the chemistry, biochemistry, and toxicology of organochlo-rine insecticides. 

Moore, N.W. and Walker, C.H. (1964). Organic chlorine insecticide residues in wild birds. Nature 201, 1072-1073. 

Turtle, E.E., Taylor, A., and Wright, E.N. et al. (1963). The effects on birds of certain chlorinated insecticides used as seed dressings. Journal of the Science of Food and Agriculture 14, 567-577. 

Table IX. Residual Toxicity of Chlorinated Insecticides to Adult Male German Roaches...

Biological systems are, in general, specialized as regards steric factors. Although the biological chemistry involved in the action of the chlorinated insecticides is still unknown, the data of this paper suggest the relative importance of steric factors in the action. 

Work on the determination of chlorinated insecticides has been almost exclusively in the area of gas chromatography using different types of detection systems, although a limited amount of work has been carried out using liquid chromatography and thin-layer chromatography. 

Aspila et al. [338] reported the results of an interlaboratory quality control study in five laboratories on the electron capture gas chromatographic determination of ten chlorinated insecticides in standards and spiked and unspiked seawater samples (lindane, heptachlor, aldrin, 5-chlordane, a-chlordane, dield-rin, endrin, p, p -DDT, methoxychlor, and mirex). The methods of analyses used by these workers were not discussed, although it is mentioned that the methods were quite similar to those described in the water quality Branch Analytical Methods Manual [339]. Both hexane and benzene were used for the initial extraction of the water samples. 

In actual practice, environmental samples which are contaminated with PCB are also highly likely to be contaminated with chlorinated insecticides. Many reports have appeared discussing co-interference effects of chlorinated insecticides in the determination of PCB and vice versa, and much of the more recent published work takes account of this fact by dealing with the analysis of both types of compounds. This work is discussed below. 

Musty and Nickless [353] used Amberlite XAD-4 for the extraction and recovery of chlorinated insecticides and PCBs from water. In this method a glass column (20 x 1 cm) was packed with 2 g XAD-4 (60 - 85 mesh), and 1 litre of tap water (containing 1 part per 109 of insecticides) was passed through the column at 8 ml/min. The column was dried by drawing a stream of air through, then the insecticides were eluted with 100 ml ethyl ether-hexane (1 9). The eluate... 

Amberlite XAD-2 resin is a suitable adsorbent for polychlorinated biphenyl and chlorinated insecticides (DDT and metabolites, dieldrin) in seawater. These compounds can be suitably eluted from the resin prior to gas chromatography [356,358]. 

Picer and Picer [357] evaluated the application ofXAD-2, XAD-4, and Tenax macroreticular resins for concentrations of chlorinated insecticides and polychlorinated biphenyls in seawater prior to analysis by electron capture gas chromatography. The solvents that were used eluted not only the chlorinated hydrocarbons of interest but also other electron capture sensitive materials, so that eluates had to be purified. The eluates from the Tenax column were combined and the non-polar phase was separated from the polar phase in a glass separating funnel. Then the polar phase was extracted twice with n-pentane. The -pentane extract was dried over anhydrous sodium sulfate, concentrated to 1 ml and cleaned on an alumina column using a modification of the method described by Holden and Marsden. The eluates were placed on a silica gel column for the separation of PCBs from DDT, its metabolites, and dieldrin using a procedure described by Snyder and Reinert [359] and Picer and Abel [360]. 

Gonzalez, M.J., M.A. Fernandez, and L.M. Hernandez. 1991. Levels of chlorinated insecticides, total PCBs and PCB congeners in Spanish gull eggs. Arch. Environ. Contam. Toxicol. 20 343-348. 

Mora, M.A., H.J. Auman, J.P. Ludwig, J.P. Giesy, D.A. Verbrugge, and M.E. Ludwig. 1993. Polychlorinated biphenyls and chlorinated insecticides in plasma of Caspian terns relationships with age, productivity, and colony site tenacity in the Great Lakes. Arch. Environ. Contam. Toxicol. 24 320-331. 

Rachel Carson s book Silent Spring that was published in 1962, was the first popular work to bring the uncontrolled environmental contamination by pesticides to public attention. Well-publicized and well-organized campaigns were mounted in several countries to prohibit the use of DDT and other persistent chlorinated insecticides such as Aldrin and heptachlor. Governments in many developed countries like USA,... 

This technique has been applied to the determination of chlorinated insecticides, carbamate insecticides and substituted urea type herbicides in soil and chloroaliphatic hydrocarbons in non-saline sediments. Separation is usually achieved on thin layers of silica gel or alumina. 

This technique has been used for the determination of polychlorobiphenyls, polychlorodibenzo-p-dioxins, polychlorodibenzofurans, alkyl phosphates, chlorinated insecticides, organophosphorus insecticides, triazine herbicides. Dacthal insecticide, insecticide/herbicide mixtures, mixtures of organic compounds and organotin compounds in soils, and polyaromatic compounds, polychlorobiphenyls, chlorinated insecticides and organotin compounds in non-saline sediments and anionic surfactants in sludges. 

In non-saline sediments aliphatic and polyaromatic hydrocarbons, phthalate esters carboxylic acids, uronic acid aldoses chloroaliphatics haloaromatics chlorophenols chloroanisoles polychlorobiphenyls polychlorodibenzo-p-dioxins poychlorodibenzofurans various organosulphur compounds, chlorinated insecticides, organophosphorus insecticides mixtures of organic compounds triazine herbicides arsenic and organic compounds of mercury and tin. 

In sludge anionic and non-ionic surfactants carboxylic acids hhydroxybutyrate hydroxy valerate chloroaliphatic compounds chlorophenols polychlorobiphenyls 4-nitrophenol mixtures of organic compounds chlorinated insecticides, phenoxy acetic acid type herbicides and organotin compounds. 

This technique has been used to determine the following types of organic compounds in soil polychlorobiphenyls, chlorinated insecticides, triazine herbicides, paraquat and diquat. 

---