Tripolyphosphate, effect

Phospha.tes, Pentasodium triphosphate [7758-29-4] sodium tripolyphosphate, STPP, Na P O Q, is the most widely used and most effective builder in heavy-duty fabric washing compositions (see also Phosphoric acid and phosphates). It is a strong sequestrant for calcium and magnesium, with a p c of ca 6, and provides exceUent suspending action for soils. Because of its high sequestration power, it also finds extensive appHcation in automatic-dishwashing detergents. Sodium tripolyphosphate forms stable hydrates and thus aids in the manufacture of crisp spray-dried laundry powders. 

Tetrasodium pyrophosphate [7722-88-5] Na4P20y, is another important primary builder and detergent. In sequestration, it is not quite as effective as sodium tripolyphosphate and its usage in heavy-duty laundry powders has declined in recent years. Functionally, tetrasodium pyrophosphate is both a builder for surfactants (ie, water softener) and alkaH. 

The efforts of the detergent industry toward solution of its part of the eutrophication problem are, at this point, less complete than its response to the biodegradabihty problem. Soda ash, Na2C02, sodium siUcate, and, to a lesser extent, sodium citrate formed the basis of the early formulations marketed in the areas where phosphates were harmed. Technically, these substances are considerably less effective than sodium tripolyphosphate. As a precipitant builder, soda ash can lead to undesirable deposits of calcium carbonate on textiles and on washing machines. 

Figure 10.1 Types of phosphate structures, (a) Where x = 12 to 14, the structure represents sodium polyphosphate, a phosphate typically used in HW heating and industrial steam boiler formulations. The structure is ill defined and described as glassy rather than crystalline. Where x = 2, it represents sodium tripolyphosphate, (b) This is the structure where effectively, x = 0, and represents trisodium phosphate (sodium orthophosphate), which is commonly supplied in either crystalline or anhydrous powder form and used as an alkalinity booster, boiler boil-out cleaner, and metal surfaces passivator.

The proposed mechanism of effect of surfactant and ultrasound is reported in Fig. 7.5. The long chain surfactant molecules attach to surface of nanoparticles due to physical adsorption. Only thin layer is adsorbed onto the CaC03 nanoparticles. Due to presence of ultrasound and use of surfactant will control the nucleation. Surfactant keeps the particles away from each other by preventing flocculation due to change in surface tension of reaction mass. The concentration of additives was changed from 0.2 to 1.0 g/L. Addition of 0.2 g/L tripolyphosphate shows the increase in the rate of precipitation which is determined from the Ca(OH)2 consumption. Polyacrylic acid shows the least rate of precipitation (0.115 mol/1), which... 

Various polyphosphates are effective sequestering agents under appropriate conditions. The best known of these is sodium hexametaphosphate (10.14), the cyclic hexamer of sodium orthophosphate. Further examples are the cyclic trimer sodium trimetaphosphate (10.15), as well as the dimeric pyrophosphate (10.16), the trimeric tripolyphosphate (10.17) and other linear polyphosphates (10.18). All of these polyanions function by withdrawing the troublesome metal cation into an innocuous and water-soluble complex anion by a process of ion exchange as shown in Scheme 10.7 for sodium hexametaphosphate. Hence these compounds are sometimes referred to as ion-exchange agents. 

Phosphate in combination with NaCl has a beneficial effect on the waterbinding capacity of processed meat products for a detailed description, see Schmidt.227 The effect of phosphates is suggested to be alterations in pH or ionic strength, sequestration of metal ions, dissociation of actomyosin and depolymerisation of myosin.103,104,228,229 However, before action, added phosphates must be hydrolysed by muscle phosphatases or non-enzymatically. Belton et al.230 studied the hydrolysis of pyrophosphate and tripolyphosphate in comminuted chicken meat using 31P NMR spectroscopy, and found that the rate of hydrolysis was dependent on the length of ageing period of the muscle as well as the presence of NaCl. Li et al.231 studied the hydrolysis of various types of phosphates in intact chicken muscle with a similar approach by 31P NMR spectroscopy and thereby demonstrated differences in rate of hydrolysis of various phosphates. The findings of these studies... 

Table I. Effects of 17o Orthophosphate, Tripolyphosphate, and Hexametaphosphate on Calcium Solubility from Ground Beef or Soy Protein Concentrate Subjected to In Vitro Gastric and Gastrointestinal Digestions...

Treatment of 9-(/ -D-ribofuranosyluronic acid)adenine with diphenylphosphoro-chloridate and orthophosphate or tripolyphosphate yields (62) and (63), which, although unstable, inhibit rabbit AMP aminohydrolase and pyruvate kinase, respectively, with behaviour characteristic of active-site-specific reagents.98 Adenylate kinases from several sources are inactivated by iV6-[2- and 4-fluorobenzoyl]-adenosine-5 -triphosphates, with kinetics characteristic of active-site labelling, although these compounds were without effect on yeast hexokinase and rabbit pyruvate kinase.99... 

Sodium tripolyphosphate is the main phosphate found in detergents. It acts as a water softener and counteracts the elements that are responsible for hard water while at the same time making the detergent a more effective cleaner. 

Sodium tripolyphosphate is made by the reaction of phosphoric acid and sodium carbonate in the proper amounts to give a 1 2 ratio of monosodium and disodium phosphates and then heating to effect dehydration at 300-500°C. 

Molecular conformation may additionally be of considerable importance and the effect of pH is another factor as is the nature of the counterions as was found in an earlier study of tripolyphosphate. <1965 30) A clear relationship of the mean 27(POP) in ATP with pH has recently been found (Fig. 9) and is similar to that observed in ADP. Other examples have also been considered, the values of which are shown in... 

The problematic agent in this list are builders, compounds that sequester ("capture") mineral ions such as calcium and magnesium that would otherwise reduce the sudsing properties of a cleaning agent. One of the most effective builders ever discovered, and one that was widely used for many years, is sodium tripolyphosphate (TPP). The structure of this molecule is such that it can surround and trap ions (such as Ga "" and Mg "") that are responsible for the "hardness in water (which reduces the effectiveness of a detergent). 

The method used for determination of PolyP, which is based on the Mn2+-induced quenching of the fluorescence of the calcium indicator Fura-2, has been described (Lorenz et al., 1997a). The effect of Mn2+ ions on the Fura-2 fluorescence is gradually removed in the presence of increasing PolyPs concentrations this allows the quantification of PolyPs isolated from tissues or cells. The described method has some advantages when compared with the conventional detection procedures based on the metachromatic effect. It can be applied to the determination of pyrophosphate, tripolyphosphate and other short-chain PolyPs not detectable by toluidine blue (Lorenz et al., 1997a). 

The enzyme with adenosine-tetraphoshatase activity was obtained earlier from rabbit muscle (Small and Cooper, 1966). This enzyme had an effect on inosine tetraphosphate and tripolyphosphate but showed little or no activity with other nucleotides or PolyPs. 

In our search for nitrite alternatives, as far as flavor and oxidative stability Is concerned, we examined the effect of commonly used adjuncts In meat curing, as well as a large ntimber of antloxldant/sequesterant systems (40-42). In particular, the effect of sodium ascorbate (SA) and sodium tripolyphosphate (STFF) on the oxidative state of cooked meats was studied. These additives lowered the TEA numbers by a factor of about 2 and 4, respectively (Table IV). When used In combination, a strong synergism was observed. Furthermore, an Increase In the concentration of SA and/or STFF resulted In a decrease In the TEA values as depicted In Figure 6 (43). Addition of 30 ppm of butylated hydroxyanlsole (EHA) or tert-butylhydroqulnone (TEHQ) further reduced the TEA numbers and In fact the latter values were even lower than those obtained for meats treated with sodium nitrite (Table IV) (41). 

Figure 6. 3-D plot showing the effect of sodium tripolyphosphate...

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