Insecticides chlorinated hydrocarbons

Weil LG, Dure G, Quentin KL. 1974. [Solubility in water of insecticide chlorinated hydrocarbons and polychlorinated biphenyls in view of water pollution.] Z Wasser Abwasser Forsch 7 169-175. (German)... 

The report by Haas and Guardia (18) pertains to their efforts to apply immunological methods for the assay of pesticide residues, and expresses their aim to test the suitability of methods for field analytical purposes. Haas and Guardia also used DDT and malathion to represent two of the most important classes of insecticides, chlorinated hydrocarbons and organophosphorus compounds. They first attempted to prepare insecticide-protein antigens in which enzymes were used as the protein carrier. Antiserum of rabbits injected with DDA-carbonic anhydrase or malathion-chymotrypsin failed to show the presence of the respective antibodies. 

Two general classes of insecticides, chlorinated hydrocarbons and organic phosphorus compounds, are used. The former have been recog-... 

Weil, L., G. Dure, and K.E. (Juentin. Solubility in Water of Insecticide Chlorinated Hydrocarbons and Polychlorinated Biphei rls in View of Water Pollution, Z Wasser Forsch., 7(6) 169-175 (1974). 

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). 

The variation in toxicity of common organophosphate insecticides is exemplified in Table 5.37. The range of chlorinated hydrocarbon insecticides (Table 5.38) have, with the exception of Endrin and Isodrin, somewhat lower oral and dermal toxicities. The toxicities of a range of oilier insecticides, fungicides, herbicides and rodenticides are summarized in Table 5.39. 

Table 5.38 Chlorinated hydrocarbon insecticides (see also Table 5.12) ...

Koeman, J.H. and van Genderen, H. (1970). Tissue levels in animals and effects caused by chlorinated hydrocarbon insecticides, chlorinated biphenyls, and mercury in the marine environment along the Netherlands coast. FAO Technical Conference on Marine Pollution. Rome, December 1970. 

The relative immobility of the chlorodioxins is expected, based on the very low solubility of these compounds in water (0.6 / g/liter). In contrast, the herbicide, 2,4,5-T, is relatively mobile in sandy soils, but movement decreases as soil organic matter increases. What does this information tell us, and how does it compare with other organic compounds A mobility scale has been devised for a large number of pesticides (3). Higher mobility numbers reflect increased compound mobility in soils. The dioxins would be in Class 1—i.e., they are immobile in soils and would compare with several chlorinated hydrocarbon insecticides. 

Paraquat Pesticides (includes acaricides, avicides, bactericides, insecticides, molluskicides, nematocides, piscicides, rodenticides) L S Chlorinated hydrocarbons (q.v.) Carbamates (q.v.) Organophosphorus compounds (q.v.) Herbicide... 

The total-chlorine method has been used extensively in the determination of spray residues of the chlorinated hydrocarbons 56). Usually the kind of insecticide applied has been known, and by means of the proper factor the chlorine values could be calculated to the insecticide originally used. This calculation is not entirely valid, as the determinations do not differentiate between the insecticide and its degradation products or other contaminants containing organic chlorine. The values obtained by the total-chlorine method are useful, however, because they indicate the magnitude of the residue and the analysis can be made in a short time with standard laboratory equipment. 

The total-chlorine method for residues of the chlorinated hydrocarbons has also been applied to animal tissues, milk, and dairy products (9). As in the spray-residue determinations, the method does not differentiate between the insecticide and metabolites. 

Methods based on color reactions have been published for several of the chlorinated hydrocarbon insecticides. Although most colorimetric methods are much more specific... 

More experimental work has been done with DDT than with all the other five chlorinated hydrocarbons combined, probably because DDT was the first of the group found to have insecticidal value. Carter (10) has summarized the several colorimetric methods for DDT. The one proposed by Stiff and Castillo (51), as modified by Claborn (14), and the one by Schechter and Haller (47) have probably been most widely used. In the Stiff and Castillo method, when the DDT is heated in pyridine solution containing xanthydrol and potassium hydroxide, a red color develops which is proportional to the quantity of DDT present. The reaction is sensitive to 10 micrograms. As TDE does not give a color with this reagent, Claborn (14) has proposed the reaction for the determination of DDT in the presence of TDE. He has also shown that for the development of the color the amount of water in the pyridine is critical. 

Methods utilizing characteristic physical properties have been developed for several chlorinated hydrocarbon insecticides. Daasch (18) has used infrared spectroscopy for the analysis of benzene hexachloride. By this means it is possible to determine the gamma-isomer content, as well as that of the other isomers of technical benzene hexachloride, provided the product is substantially free of the higher chlorinated cyclohexanes. 

The use of chlorinated hydrocarbon insecticides for the control of insects affecting field crops and farm animals has created interest in the amounts of these materials that may be found in products intended for human and animal consumption. 

Making a list, Muller outlined the desirable characteristics of an ideal insecticide. It should be toxic to insects but harmless to mammals, fish, and plants act rapidly have no irritating odor and be inexpensive. To his list, Muller added two more properties. The ideal insecticide should affect as many kinds of insects as possible, and it should be chemically stable for a long time. Finally, Muller decided to use as a starting point Geigy s mothproofing compound, the chlorinated hydrocarbon that was extremely stable on woolens. Thus, from the beginning, Muller s search contained the seeds of its own disaster. In the future, it would kill beneficial as well as harmful insects, and it would persist for decades in the environment. 

Muller had several clues to guide his search. First, he knew from Henri Martin s mothproofing work that a chlorinated hydrocarbon worked as a gastric moth poison. Second, his early experiments showed him that compounds with the group CH2C1 had some insecticidal effect. Third, a 1934 article in the Journal of the Chemical Society of London described the preparation of diphenyltrichloroethane, which Muller found to be somewhat poi-... 

Today, marketing a new insecticide can take a decade, but Geigy did it in three years. In 1942, Geigy sold almost a pound per capita of DDT-laced insecticide in Switzerland and saved the country s wartime potato crop from a heavy infestation of Colorado beetles. With the discoveries of organophosphate in Germany and chlorinated hydrocarbons like DDT in Switzerland, the era of synthetic chemical pesticides had begun. 

This technique has been applied to the concentration of organochlorine and organophosphorus insecticide [7,8] and various ethers, glycols amines, nitriles, hydrocarbons, and chlorinated hydrocarbons. Although this work was concerned with drinking water, it is a useful technique which may have application in seawater analysis. Cellulose acetate [9], ethyl cellulose acetate [6], and crosslinked polyethyleneinine [8] have been used as semi-permeable membranes. 

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]. 

Chlorinated hydrocarbons Cholinesterase inhibitors Botanical insecticides... 

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