Phosphate disodium

Fractional extraction has been used in many processes for the purification and isolation of antibiotics from antibiotic complexes or isomers. A 2-propanol—chloroform mixture and an aqueous disodium phosphate buffet solution are the solvents (243). A reciprocating-plate column is employed for the extraction process (154). 

An improved version of the THPC—amide process, developed in 1972, is based on a finish containing THPC, cyanamide, and disodium phosphate [13708-85-5] Na2HP04. It has the advantage of removing the mutagenicaHy suspect TMM from the finish while retaining many of its attributes (81). 

THPC—Urea—Dlsodium Phosphate. A further improved variation uses a combination of THPC, urea, and disodium phosphate (82,83). 

A cmcial development for zinc phosphate coatings came in 1943 when it was found that more uniform and finer crystals would develop if the surface was first treated with a titanium-containing solution of disodium phosphate (6). This method of crystal modification is a prime reason for the excellent paint (qv) adhesion seen on painted metal articles. 

A typical process for the preparation of a poly(methyl methacrylate) suspension polymer involves charging a mixture of 24.64 parts of methyl methacrylate and 0.25 parts of benzoyl peroxide to a rapidly stirred, 30°C solution of 0.42 parts of disodium phosphate, 0.02 parts of monosodium phosphate, and 0.74 parts of Cyanomer A-370 (polyacrylamide resin) in 73.93 parts of distilled water. The reaction mixture is heated under nitrogen to 75°C and is maintained at this temperature for three hours. After being cooled to room temperature, the polymer beads are isolated by filtration, washed, and dried (69). 

Vitamin A (845 RE/L) and vitamin D (913 RE/L) may be added to fortify evaporated milk. Other possible ingredients are sodium citrate, disodium phosphate, and salts of carrageenan. Phosphate ions maintain an appropriate salt balance to prevent coagulation of the protein (casein) during sterilization. The amount of phosphate added depends on the amount of calcium and magnesium present. 

Traditionally, phosphates have been represented as stoichiometric combinations of oxides. It is common practice to speak of the phosphates in terms of oxide ratios for example, phosphoric acid [7664-38-2] H PO, as 1.5 H2O 0.5P2O disodium phosphate [7558-79-4] Na2HP04, as Na20 O.5H2O 0.5P20 and sodium triphosphate [7601-54-9], Na P O, as 2.5 Na20 1.5P20. ... 

Both mono- and disodium phosphates are prepared commercially by neutralization of phosphoric acid using sodium carbonate or hydroxide. Crystals of a specific hydrate can then be obtained by evaporation of the resultant solution within the temperature range over which the hydrate is stable. For the preparation of trisodium phosphate, sodium hydroxide must be used to reach the high end pH because CO2 cannot be stripped readily from the solution above a pH of near 8. 

Uses. The principal use of monosodium phosphate is as a water-soluble soHd acid and pH buffer, primarily in acid-type cleaners. The double salt, NaH2P04 H PO, referred to as hemisodium orthophosphate or sodium hemiphosphate, is often generated in situ from monosodium phosphate and phosphoric acid in these types of formulations. Mixtures of mono- and disodium phosphates are used in textile processing, food manufacture, and other industries to control pH at 4—9. Monosodium phosphate is also used in boiler-water treatment, as a precipitant for polyvalent metal ions, and as an animal-feed supplement. 

Several crystalline condensed phosphates may also be formed by the dehydration of monosodium phosphate (MSP). Maddrell s salt exists as Form 11 (high temperature MaddreU, NaPO -ll, insoluble metaphosphate-11) and Form 111 (low temperature MaddreU, NaPO -lll, insoluble metaphosphate-111). Both forms are highly polymerized and difficult (slow) to dissolve in water. Mixtures of the two forms are marketed as a dental abrasive for toothpaste formulations containing soluble fluoride. Maddrell s salt is also used with disodium phosphate as a cheese emulsifying aid. 

Nutrients are usuaUy added at concentrations ranging from 0.005 to 0.02% by weight (16). In a field appHcation using hydrogen peroxide, nutrients were added to the injected water at the foUowing concentrations 380 mg/L ammonium chloride 190 mg/L disodium phosphate, and 190 mg/L potassium phosphate, the latter used primarily to complex with iron in the formation to prevent decomposition of hydrogen peroxide (24). 

Boiler feed-water systems that use dernineralized or evaporated makeup or pure condensate may be protected from caustic attack through coordinated phosphate and pH control. Phosphate buffers the boiler water, reducing the chance of large pH changes due to the development of high caustic or acid concentrations. Excess caustic combines with disodium phosphate and forms trisodium phosphate. Sufficient disodium phosphate must be available to combine with all of the free caustic in order to form trisodium phosphate. 

Disodium phosphate neutralizes caustic by the following reaction ... 

Figure 5 shows the phosphate—pH relationship recommended to control boiler corrosion. Different forms of phosphate consume or add caustic as the phosphate shifts to the proper form. For example, addition of monosodium phosphate consumes caustic as it reacts with caustic to form disodium phosphate in the boiler water according to the following reaction ... 

Inorganic compounds Monosodium phosphate mixed with boric acid and ethyl carbonate, disodium phosphate sodium aliiminate, bentonite and other solids Distillation instant coffee boiler feedwater sugar extraction... 

Chemical Designations - Synonyms Sodium phosphate is generic term and includes the following (1) monosodium phosphate (MSP sodium phospWe, monobasic), (2) disodium phosphate (DSP sodium phosphate dibasic), (3) trisodium phosphate (TSP sodium phosphate, tribasic), (4) sodium acid pyrophosphate (ASPP SAPP disodium pyrophosphate (TSPP), (6) sodium metaphosphate (insoluble sodium metaphosphate), (7) sodium trimetaphosphate, and (9) sodium tripolyphosphate (STPP TPP) Chemical Formula (1) NaHjPO (2) Na HPO (3) NajPO (4) Na H P O, (5) Na P O, (6) (NaPOj) (7) (NaP03)3 (8) (NaP03) NaO (9) Na,P30,o. 

Preparation of Prednisolone 21-Disodium Phosphate Acetonitrile (50,0 ml) containing... 

The mixture was refluxed for 2.75 hours and the solvent was then evaporated under reduced pressure to give a yellow oil. The oil was taken up in methanol (25 ml) and titrated to pH 10.9 with sodium hydroxide in methanol (N) using a pH meter. The precipitate was filtered off and the filtrate evaporated to a gum under reduced pressure. The gum was taken up in methanol (5 ml), filtered through filter paper and acetone (100 ml) was added to the filtrate. The precipitate was filtered off, washed with acetone and dried at 100°C/1 mm for 0,75 hour giving a pale yellow solid, prednisolone disodium phosphate (0.74 gram), which was completely soluble in water, according to U.S. Patent 2,936,313. 

The inhibition of Streptococcus mutans adherence to hydroxyapatite with combinations of alkyl phosphates and nonionic surfactants was tested. Seven alkyl phosphate derivatives and three nonionic surfactants were examined for their ability to inhibit the adherence of 3H-labeled cells of S. mutans to hydroxyapatite treated with buffer or parotid saliva. No compound by itself effectively hindered binding of bacteria to hydroxyapatite. A combination of certain of the alkyl phosphates, notably a disodium phosphate of 1-octadecanol, and nonionic surfactant at a 1 1 molar ratio gave a strong inhibition of S. mutans adherence. Treatment with this combination resulted in 98% reduction of adherence. Adsorption of the two types of surface-active agents alone and in combinations was studied using 14C-labeled agents. Electrophoretic measure-... 

Between 5 and 10 individual fruits were each sliced into 16 parts. Randomly 20 to 40 parts were selected and homogenized in a juicer. 10 gm of the mixture was weighed into a blender with 3 g of anhydrous disodium phosphate, 10 g of anhydrous sodium sulfate and... 

CQHuNjNajOgP S H20 2 -Deoxyuridine 5 -(disodium phosphate), pentahydrate (NADOUR)186... 

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