Monomethyl phosphate

Dichlorobiphenvl. PCB-1016, PCB-1232, PCB-1242, PCB-1248, PCB-1254, PCB-1260 Monoisopropyl carbonate, see Chlornronham. Pronham Monomethyl phosphate, see Malathion Monomethyl phthalate, see Dimethyl phthalate Monomethyl p3uazole, see Difenzoguat methyl sulfate Monomethyl tetrachloroterephthalate, see Chlorthal-dimethvl... 

In order to obtain more information on the solvation process Yang and Cui performed a so called natural energy decomposition analysis (NEDA) on monomethyl phosphate ester (MMP) solvated in water. They used a supermolecular approach where the solute plus a number of water molecules (up to 34) were treated quantum-mechanically. A further set of water molecules was treated with a force-field model. Their results indicate that there is a substantial charge transfer between the solute and the nearest solvent molecules. The interaction energy due to this transfer was found to amount to some 70-80% of that of the electric interactions. Since MMP forms hydrogen bonds with the water molecules, all results together suggests that for such a system it is important to include the nearest solvent molecules in the quantum-mechanical treatment, whereas a continuum approximation or a force field may not be sufficiently accurate. 

Animals exposed to dichlorvos vapor were found to absorb at least 50% of the total material by the respiratory route. Dichlorvos can also be absorbed through the oral and dermal routes. Following oral exposure, dichlorvos is rapidly detoxified in the liver. Metabolites include 0,0 -dimethyl phosphate, monomethyl phosphate, 0-methyl-0-2,2-dichlorovinyl phosphate (desmethyl dichlorvos), and inorganic phosphate. Detoxification processes for dichlorvos are also found in plasma. 

Chemical and Agrochemical Applications Mohsin [263] developed an IC-MS method using thermospray and electrospray interfaces for the analysis of organophosphorus and organosulfur compounds in an insecticide such as monomethyl phosphate, monomethyl sulfate, and dimethyl phosphate. All three compounds were separated on an lonPac ASH anion exchanger using a NaOH/ methanol mixture as an eluent. Mohsin used an Alltech lOOOHP suppressor to convert the eluent to water prior to entering the MS interface. The Alltech lOOOHP suppressor contains two packed-bed suppressor columns. One of the... 

The anionic product causes electrostatic repulsion of any incoming hydroxide, so that monomethyl phosphate will not readily form. The half-life of this latter reaction is 16 days at 100°C, and the mechanism involves exclusively alkyl fission as the phosphorus atom is less accessible ... 

Fig. 6. Hydrolysis of monomethyl phosphate. A, experimental curve B, calculated for decomposition of the monoanion . ...

Figure 6-18 shows a bell-shaped pH-rate profile for the hydrolysis of monomethyl dihydrogen phosphate. Other examples are the hydrolysis of o-carboxyphenyl hydrogen succinate and the hydration of fumaric acid. ... 

These are the most common class of complex lipid (Figure 12.11) and contain a phosphoric acid residue (phosphate group) and two fatty acids esterified to glycerol. Attached to the phosphate group is an amino alcohol, sometimes referred to as the nitrogenous base, which may be either serine, choline or ethanolamine or sometimes the monomethyl or dimethyl derivatives of ethanolamine (Table 12.4). Alternatively, a polyhydroxy compound which is either glycerol, myo-inositol or one of their derivatives is attached instead... 

Composi ti on % Wt Water 75.0 Metso Beads 2048 5.0 Sodium Hydroxide (50%) 1.0 Diethanolamine (98%) 1.0 EDTA, Tetrasodium (37%) 6.0 Dipropylene Glycol Monomethyl Ether 4.0 Phosphate Ester 3.0 Nonylphenoxy Polyethoxyethanol, 9-10 Mole EO 5.0... 

Water 75% Metso Beads 2048 sodium metasilicate 5% Sodium hydroxide (50%) 1% Diethanolamine 1% EDTA, tetrasodium (37%) 6% Oipropylene glycol monomethyl ether 4% Phosphate ester 3% Nonylphenol, 9-10 moles EO 5%... 

The thermodynamically favoured oxidation state of tin (Sb) is +V However, in contrast to the tetrahedral coordination of phosphate and arsenate, Sbv is present in octahedral coordination as Sb(OH) 5 over a wide range of pH. Sbm has been reported in seawater at concentrations in the order of less than or equal to 10% of Sbv. The dominant form of Sbm in seawater should be Sb(OH)3. While methylated Sb is observed in seawater, in contrast to As, monomethylated forms are more abundant than dimethyl forms. Monomethyl Sb should be strongly hydrolysed in solution, probably in the form of CH3Sb020H. ... 

Hydration of aryl-substituted epoxides. Treatment of aryl-substituted oxiranes with copper(II) sulfate and pyridine in an aqueous phosphate buffer (pH 7) affords cis-diols by reaction of water at the benzylic position. Less than 15% of trans cleavage products obtain. In the absence of pyridine, the oxides are rapidly destroyed. Triethylamine cannot be substituted for pyridine. cis-Chlorohydrins are obtained when aryl-substituted oxides are treated with copper(II) sulfate, pyridine, and kiCl in THF, When methanol is used as solvent, the corresponding cis-glycol monomethyl ether is obtained. In all cases substitution occurs at the benzylic position. Alkyl oxiranes do not react under these conditions. ... 

Adsorption processes may be particularly important in influencing species concentrations, since the arsenic present in the pore waters will probably be in equilibrium with arsenic adsorbed on solid surfaces. Arsenic in any species measured in pore waters may be only a fraction of the total amount of that species present in the sediments, the rest being adsorbed to or incorporated into particulate matter. Thus, it is important to study the sorptive characteristics of each of the arsenic species in the sediments. In the Menominee River sediments studied, the four oxygenated arsenic species (arsenate, arsenite, monomethyl arsonic acid and cacodylic acid) are often present together and competing among themselves and with phosphate for the same sorption sites. The competitive adsorptive characteristics of the species could greatly influence... 

The constants given In Table IV show the strong adsorption of phosphate and arsenate relative to cacodyllc acid, with monomethyl arsonic acid Intermediate. Constants for the adsorption of arsenate on amorphous Iron and aluminum hydroxide are also Included In Table IV to compare the sediments with well-characterized adsorbents. It was assumed that loss from... 

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