Pesticides phosphoric acid

It is used to make safety matches, incendiary shells, and smoke bombs in pyrotechnics and in the manufacture of fertihzers, pesticides, phosphoric acid, and phosphoms halides. 

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). 

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. 

Other interesting examples of proteases that exhibit promiscuous behavior are proline dipeptidase from Alteromonas sp. JD6.5, whose original activity is to cleave a dipeptide bond with a prolyl residue at the carboxy terminus [121, 122] and aminopeptidase P (AMPP) from E. coli, which is a prohne-specific peptidase that catalyzes the hydrolysis of N-terminal peptide bonds containing a proline residue [123, 124]. Both enzymes exhibit phosphotriesterase activity. This means that they are capable of catalyzing the reaction that does not exist in nature. It is of particular importance, since they can hydrolyze unnatural substrates - triesters of phosphoric acid and diesters of phosphonic acids - such as organophosphorus pesticides or organophosphoms warfare agents (Scheme 5.25) [125]. 

A variety of phosphoric acid triesters and their derivatives are used as pesticides. Although there are no natural phosphorotriesters, those artificial ones undergo decomposition in the soil, implying that some microorganisms exist which are capable of hydrolysing them. The first report on a stereoselective enzymatic phos-photriester hydrolysis was pubhshed in 1973, when Dudman and Zerner succeeded... 

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. 

Red phosphors are formed either by heating white phosphorus or by exposing white phosphorus to sunlight. It is quite different from the explosive white phosphorus. For instance, when scratched on a surface, the heads of safety matches made of red phosphorus convert back to white phosphorus and ignite due to the heat of the shght friction of the match on a rough surface. Red phosphorus is also used in fireworks, smoke bombs, and pesticides and to make phosphoric acid, electroluminescent paints, and fertilizers. 

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... 

There are two useful side products. The H2Sip6 is shipped as a 20-25 % aqueous solution for fluoridation of drinking water. Fluorosilicate salts find use in ceramics, pesticides, wood preservatives, and concrete hardeners. Uranium, which occurs in many phosphate rocks in the range of 0.005-0.03% of UsOg, can be extracted from the dilute phosphoric acid after the filtration step, but this is not a primary source of the radioactive substance. The extraction plants are expensive and can only be justified when uranium prices are high. 

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. 

The phosphoric acid triesters (organophosphates, not to be mistaken for organophosphorous pesticides) are, like phthalates, plasticizers mixed into polymers to increase flexibility and workability. Unlike phthalates they are remarkable flame retardants as well. The total European production of phosphorous-base flame... 

The fluorosilicate acid can be used for fluoridation of drinking water, and fluorosilicate salts find use in ceramics, pesticides, wood preservatives, and concrete hardeners. The phosphoric acid can be purified by a solvent extraction process (Fig. 2). 

Finally, the P-Mannich bases of phosphorous acid (521) are mainly used as complexants, as are a-amino acids 516, and pesticides, particularly herbicide.s. 

When people think of the chemical industry, they may think of the manufacturer of pesticides, pharmaceuticals, solvents, lubricants, or other relatively complex processes. Many people are surprised to learn that the vast bulk of the chemical industry revolves around the manufacture of four relatively simple chemicals sulfuric acid, phosphoric acid, sodium hydroxide, and our old friend, sodium chloride. 

Applications In 1994 about half of the Phosphorus(III) chloride consumed in the USA was utilized in the manufacture of the intermediate phosphorous acid, a further 19.4% to phosphorus(V) oxychloride. Di and trialkylphosphonates, triarylphosphonate, pho.sphorus(V) sulfochloride and phosphorus(V) chloride are also manufactured directly from pho.sphorus(III) chloride. Broken down according to the field of application of the end products, the consumption of phosphorus(IIl) chloride is the USA in 1994 53.6% was utilized for pesticide production (mainly for glyphosphate), 18% for the manufacture of water treatment chemicals (phosphonic acids) and tensides (acid chlorides of fatty acids and secondary products), 17.1% in the manufacture of polymer additives (flame retardants, stabilizers etc.) as well as small quantities for the production of hydraulic fluids, lubricants and additives for lubricating oils. 

Phosphoric acid diesters are utilized as wetting agents and antistatica for textiles and as emul.sifiers for cosmetics, cutting fluids, pesticides formulations, in polymerization reactions etc. 

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