Polyphosphate reactivity

Panswad T, Iamsamer K, Anotai J (2001) Decolorization of azo reactive dye by polyphosphate and glycogen accumulating organisms in an anaerobic aerobic sequencing batch reactor. Bioresour Technol 76 151-159... 

Cambella and Antia [385] determined phosphonates in seawater by fractionation of the total phosphorus. The seawater sample was divided into two aliquots. The first was analysed for total phosphorus by the nitrate oxidation method capable of breaking down phosphonates, phosphate esters, nucleotides, and polyphosphates. The second aliquot was added to a suspension of bacterial (Escherichia coli) alkaline phosphatase enzyme, incubated for 2h at 37 °C and subjected to hot acid hydrolysis for 1 h. The resultant hot acid-enzyme sample was assayed for molybdate reactive phosphate which was estimated as the sum of enzyme hydrolysable phosphate and acid hydrolysable... 

Polymer chemistry shows that the larger the various polymers become, the more their reactivity becomes independent of the length of the polymer chains. This fact, known as the principle of equal reactivity of cocondensing functional groups, has been verified in fused polyphosphate systems (which, for several properties, may be considered as analogous to silicate melts cf Fraser, 1977) with polymeric chains longer than 3 units (Meadowcroft and Richardson, 1965 Cripps-Clark et ah, 1974). Assuming this principle to be valid, the equilibrium constant of reaction 6.4 ... 

Addition of sodium polyphosphate appreciably altered the rate constants for reactions (19)—(21) and stabilized the small non-metallic silver clusters [512, 513]. Advantages of the steady-state and pulse-radiolytic approaches to silver-cluster formation are manifold. Firstly, experimental conditions can be precisely adjusted such that the reactive species is exclusively e or, alternatively, that it is a known alcohol radical. Secondly, the concentration of the reducing species (the number of reducing equivalents generated) is readily calculable. Thirdly, in time-resolved experiments, rate constants for the individual reaction steps can be determined by monitoring absorption and/or conductivity changes. These latter determinations permitted the assessment of agglomeration numbers [512,513]. 

In an effort to use [Rh(H20)6]3+ as a redox-stable, diamagnetic probe, its reactivity with a variety of polyphosphates has been explored.1159,1160 Several complexes of the form [Rh(H20)4(PP)]" (PP = 2P04-, HP20/, HP2C>8, ADP or ATP) have been prepared, and characterized by electronic spectroscopy."60 The potential tridentate H2P3O 0 (PPP) is reported to form [Rh(H20)(PPP)].116°... 

Up to a certain ratio, r, of (twice) the Co2+ and polyphosphate (PP) anions concentrations, t3 remains unaltered. As the reaction of Ps with Co2+ is spin conversion [15], this is due to the formation of the inner sphere PP/Co2+ complexes, which make the odd electrons of Co2+ unavailable to Ps. At a given value r = Rc0, tight binding ceases and the Co2+ ions recover the reactivity towards Ps they would have in pure water Rc is found to coincide closely with the theoretically expected value [15]. 

These units can be distinguished by chemical reactivity differences (branch points are rapidly hydrolyzed) and by 31P nmr spectra. Combinations of these units can give rise to four main types of polyphosphates ... 

DIP is equivalent to the soluble reactive P (SRP) pool, which may include some phosphate derived from hydrolysis of DOP (e.g., see Monaghan, and Ruttenberg, 1998). DOP is equivalent to the soluble nonreactive P (SNP) pool which may include dissolved inorganic polyphosphates... 

The condensed phosphates or polyphosphates are another important class of inorganic phosphates. In these compounds, two or more phosphate groups bond together via P - O - P bonds to form chains or in some cases cyclic species. In soils and waters polyphosphates generally account for only a small part of the total P content. However, these species are very reactive and in many places they are responsible for anthropogenic pollution of natural water, for instance, by detergents. The polyphosphates are formed also in reactions between orthophosphates of mineral fertilizers and soil organic matter and can be leached to surface waters (Kudeyarova and Bashkin, 1984 Kudeyarova, 1996). 

Problems with protection For the phosphorylation of the specified free hydroxyl groups, a short access to a properly protected inositol is required. Although the protection technology has developed enormously, in the case of inositol and its derivatives, the straightforward protection of some of the six hydroxyls is still quite difficult due to their similar reactivities. Some useful protecting methods have been recently reported in relation to the synthesis of inositol polyphosphates. 

Rates of solvolysis of phenyl and methyl polyphosphates in water and alcohols have been measured and the reasons for the enhanced reactivity of the former relative to the phenyl phosphorochloridate discussed. From studies on a series of substituted aryl sulphatophosphates (19) it was... 

In the study of water nutrients, nearly half of the participants obtained poor results in the analysis of silica because they failed to digest the sample with sodium bicarbonate to convert it all to molybdate-reactive silica. Similarly, in the analysis of phosphates, only about half of the participants hydrolyzed the sample to convert the polyphosphates to ortho phosphate and hence, the remainder obtained low results. In silicate... 

The hydrolysis of condensed phosphates during the orthophosphate analysis was virtually eliminated by minimizing contact time between the acidic reagents and the sample. Negative results were obtained when concentrated solutions of sodium tripolyphosphate were analyzed by this technique, however in the reactive phosphate technique of Strickland and Parsons (20)—a widely used oceanographic method—considerable hydrolysis of the polyphosphate took place. 

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