Pesticides phosphoric acid esters

Figure 3.26 Chromatograms of the M series and of pesticides (phosphoric acid esters) on coiumns of different poiarities...

The retention and acquisition parameters of common nitrogen- and phosphorus-containing pesticides (phosphoric acid esters, atrazines, etc.) are listed in Table 4.13. It is recommended that the excitation parameters are used initially with equal standard values (0.9 V), which may be slightly adjusted in the case of response optimization. The quality of the product ion spectra is not affected (Figure 4.51). A typical standard run in MS/MS acquisition mode is shown in Figures 4.52 and 4.53. Even at the low 10 pg/pL level, the compounds are detected with high S/N values and full MS/MS product spectra for confirmation (Figure 4.51). 

Parathion, a heavily-used pesticide with strongly adverse environmental effects, is a member of the phosphoric acid esters group with a general formula of the type... 

A full discussion of these models will follow in Section 21.3. At this point we will deal only with a special version of Eq. 21-30 in which there is no back-reaction from B to A and no external input of chemical B. As an example imagine the case of the pollution of a pond by a pesticide A that in the water is transformed into another compound B that is more toxic than the original compound. For instance, thiophos-phoric acid ester is transformed to the corresponding phosphoric acid ester (see Chapters 2 and 13). Then it would be important to predict the maximum concentrations of A and B in the pond and to estimate the necessary time until the pollutant concentration has fallen below a certain threshold. Such a case will be discussed in Illustrative Example 21.4 below. 

Owing to the environmental dangers of mercury, its use in pesticides has been limited. In Japan, organic mercury compounds used in fungicides in rice culture were replaced by phosphoric acid esters in 1968. However, the quantity of mercury used in agriculture is responsible for only a small part of the mercury polluting the environment, and the overall problem of environmental pollution by mercury is not yet solved. 

Baasner B, Behrenz W, Homeyer B, Maurer F, Stendel W (1988) Pesticidally active O-ethyl 0-isopropyl 0-(2-trifluoromethylpyrimidin-5-yl)-phosphoric acid ester. US 4774233 A... 

Cholinesterase inhibitor (anti-cholinesterase, ChEI) is a chemical that prevents cholinesterases (ChEs) from breaking down. ACh, which consequently increases the level and duration of action of this neurotransmitter. ChEIs such as organophosphates (esters of phosphoric acid) and carbamates (esters of carbamic acid) - serve as insecticides, pesticides, warfare agents and drugs. 

The monomeric phosphate ion 102 was first postulated in 1955 as an intermediate of the hydrolysis of monoesters of phosphoric acid in an aqueous medium 57,58). Another 24 years were to elapse before compound 102 was observed directly, and then not in solution but in the mass spectra of some pesticides. The negative ion Cl spectra of enol phosphates 94 and of the thiophosphorie ester 95 display an intense peak at m/e == 78.9590, which is unequivocally assigned to the POf ion 59). 

Synonyms AI3-24988 Alvora Arthodibrom BRN 2049930 Bromchlophos Bromex Bromex 50 Caswell No. 586 Dibrom Dibromfos l,2-Dibromo-2,2-dichloroethyldimethyl phosphate Dimethyl l,2-dibromo-2,2-dichloroethyl phosphate 0,0-Dimethyl-0-(l,2-dibromo-2,2-di-chloro-ethyl)phosphate 0,0-Dimethyl 0-(2,2-dichloro-l,2-dibromoethyl)phosphate EINECS 206-098-3 ENT 24988 EPA pesticide chemical code 034401 Fosbrom Flibrom NA 2783 Ortho 4355 Orthodibrom Orthodibromo Phosphoric acid, l,2-dihromo-2,2-dichloroethyl dimethyl ester RE-4355. 

More than 90 percent of commercial phosphorus production is in the form of calcium salts of phosphoric acid, H3PO4, used as fertilizers. Other significant uses of phosphorus compounds are in the manufacture of matches (phosphorus sulfides), food products and beverages (purified phosphoric acid and its salts), detergents (sodium polyphosphates), plasticizers for polymers (esters of phosphoric acid), and pesticides (derivatives of phosphoric acid). Related to the phosphorus pesticides are nerve gases, poisonons com-potmds that rapidly attack the central nervous system, initially developed during World War II. see also Deoxyribonucleic Acid (DNA) Fertilizer Pesticides. 

Oowco 217 ENT 27521 EPA Pesticide Chemicai Code 103501 Fospirat Fospirate Fospirate methyl Fospiralo Fospiratum NSC 195058 OMS 1188 Phosphoric acid, dimethyi 3,6,6-trichloro-2-pyridyl ester Toreile. Anthelmintic. Registered by EPA as an insecticide (cancelied), Crystais mp = 86.5 88°. Dow AgroSciences Dow UK. 

Hydroxy-l,2,4-thiadiazoles readily form esters with phosphoric acid and its various analogs. Because of the pesticidal properties of these organo-phosphorus compounds, and their reported relatively low toxicity to warmblooded animals, a large volume of preparative work has been undertaken. The patent literature exemplifies almost the full range of possible phosphoric and phosphonic acid derivatives, and their thio analogs. For their production, a hydroxy-1,2,4-thiadiazole is condensed with the phosphoro- or phosphono-chloridic ester (426 or 429), in the presence of a base.332-336 Alternatively, a halogeno-1,2,4-thiadiazole is allowed to react with the appropriate free acid (424 or 427).337-341 The use of mercapto-l,2,4-thiadiazoles, or of the... 

CAS 39407-03-9 EINECS/ELINCS 201-116-6 Synonyms Phosphoric acid, octyl ester Empirical C8H19O4P Properties M.w. 210.21 anionic Uses Detergent in dry cleaning emulsifier in emulsion polymerization, pesticides, cosmetics acid catalyst in resin curing chem. intermediate in formulation of rust preventatives, antistats, textile lubricants, oil additives, heavy metal extractants Manuf./Distrib. Rhodia/Phosphorus Perf. Deri vs. 

PEG 300 tridecyl ether phosphate POE (6) tridecyl ether phosphate Definition Complex mixture of esters of phosphoric acid and trideceth-6 Properties Anionic Toxicology TSCA listed Uses Pesticide emulsifier dry-cleaning detergent textile wetting agent, antistat penetrant, lubricant for fiber and metal treatment emulsion polymerization surfactant in cosmetics emulsifier in mfg. of food-contact articles in lubricants for incidental food contact... 

Organochlorine pesticides involve organic molecules that contain several halogenated atoms, and OPPs involve esters of phosphoric, phosphonic, phosphorothioic, or related acids (20,21). Figure 1 shows the chemical structures and names of some OCPs and OPPs. 

Organophosphate pesticides are synthetic and are usually esters, amides, or thiol derivatives of phosphoric, phosphonic, phosphorothioic, or phosphonothioic acids. Over 100 organo phosphorus compounds, representing a variety of chemical, physical, and biological properties, are currently on the market (Table 23.1). 

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