Ferrous pyrophosphate

Ferrous pyrophosphate, Fe2P207, is obtained 5 as an unstable white powder by double decomposition of ferrous sulphate and sodium pyrophosphate by heating ferrous orthophosphate and by reduction of ferric phosphate with hydrogen. Upon exposure to air it turns green and ultimately brown. 

Adolfo Aquilo Have you investigated the autoxidation of ferrous fluoride and ferrous pyrophosphate ... 

Certain metaphosphates, for example, Cr and U will, on heating, decompose to phosphorus pent-oxide and pyrophosphate (5.107), while ferrous pyrophosphate can be prepared by reducing ferric orthophosphate (5.108), and mercury pyrophosphate by simply heating the orthophosphate (5.109). 

The more complex the iron salt, the more difficult its absorption. Thus, iron salts like ferric verseneate and ferrous pyrophosphate are only slightly absorbed. In contrast, ferrous sulfate and ferrous succinate are readily absorbed in the intestine. 

Heterocyclic compounds have in most cases been hydroxylated by modified forms of Fenton s reagent. For instance, EDTA or pyrophosphate have been added to the system to complex the ferrous ions. It has been shown in the reactions of bcnzenoid compounds, however, that addition of complexing agents does not affect the distribution of isomers obtained by Fenton s reagent,and therefore the hydroxyl radical must still be the hydroxylating species. 

The same principle can be applied using diisopropyl benzene dihydroperoxide (5, 181, 182). The synthesis of polymeric hydroperoxides in which the hydroperoxide groups occupy terminal positions in the polymer chain, was carried out in emulsion, using the system w-diisopropyl-benzene dihydroperoxide/ferrous ion/pyrophosphate the residual hydroperoxide groups on the polymer are protected from further reaction by the emulsion technique, the residence time in the aqueous phase being sufficiently short. 

BD-AN. Polymerization was performed chemically (cumyl hydro-peroxide/glucose/pyrophosphate/ferrous sulfate) and by radiochemical initiation (see above). Monomer ratios were VC/BD/AN = 5/3/1. 

Ferrous thio-pyrophosphate, Fe2P2S7, has been obtained by heating the metal or its sulphide with sulphur and phosphorus as in the preparation of the preceding salt. It crystallises in lustrous lamellae, which are insoluble in cold nitric acid.2... 

Iron deficiency anemia occurs mainly in infants, children, and fertile women. For this reason, a variety of foods, including infant formula and infant cereals, is fortified with iron. Ferrous sulfate is a form of iron that is most readily absorbed by the gut, but when added to dry cereals it can promote their spoilage and rancidity. For this reason, dry cereals are fortified with elemental iron particles, ferric pyrophosphate, or ferrous fumarate (Davidsson et ah, 1997). Ascorbic add may also be added to the cereal to enhance iron absorption. To view some of the numbers, infant cereals may contain 75 mg iron/kg cereal (1.3 mmol iron/kg), 1 mmol phytic acid/kg, and 2.6 mmol ascorbic acid/kg (Davidsson et cd., 1997). Although phytic acid impairs iron absorption, the added ascorbate serves to prevent this effect. An alternate method for preventing phytate from impairing iron absorption is to treat the food with the enzyme phytase. A parent interested in enhancing a child s iron absorption can easily feed a child some orange juice, but it would not be practical to pretreat the child s cereal with phytase. A typical availability of ferrous sulfate in infants is about 3-5% (with no ascorbate), and 6-10% (with ascorbate). Ascorbate is effective when present in a twofold molar excess over the iron. 

This does not mean that the bioavailability of iron from all compounds containing both phosphorus and iron is low. Wood, et al. (12) and Theuer and his associates (7, 8) have found that the bioavailability of iron from sodium iron pyrophosphate and ferric pyrophosphate was greatly improved when the foods containing these salts were processed with heat and pressure (Table II). Such processing did not, however, improve the bioavailability of iron from ferric orthophosphate or ferrous sulfate. The reason for this effect is not known but sugars in the foods may have formed chelates with the iron that facilitated absorption. 

Effect of Temperature and the Initiator System. Polymerization temperature was varied from 50° to 70°C with ICSoOs as initiator and from 40° to 60°C using a redox catalyst. The redox catalyst was (wt % ) cumene hydroperoxide, 0.75 ferrous sulfate (FeS04 7 H20), 0.01 dextrose, 1 and sodium pyrophosphate, 0.5. Cumene hydroperoxide was mixed with the monomers the other ingredients were added into the emulsifier solution. 

Hydroxylation by the Metal lon—Oxygen Systems. A monosubsti-tuted benzene was suspended in aqueous solution of a metal salt through which oxygen was bubbled. Two aromatic compounds (toluene and anisole) were treated this way with each of four metal salts (ferrous sulfate in the presence of EDTA, titanous chloride, cuprous chloride and stannous pyrophosphate) a third compound (fluorobenzene) was oxidized with the ferrous, titanous, and cuprous systems, and a fourth aromatic compound (nitiobenzene) was treated with ferrous ion with EDTA. The initial concentration of the metal ion was varied. 

Iron sesquioxide. See Ferric oxide Iron (III) sodium pyrophosphate. See Ferric sodium pyrophosphate Iron sponge, spent. See Iron oxide red Iron subcarbonate. See Iron oxide brown Iron sulfate Iron (II) sulfate (1 1). See Ferrous sulfate anhydrous... 

Salicylsulfonic acid. See 5-Sulfosalicylic acid Saline. See Sodium chloride Salinide. See Salicylanilide Salix alba Salix alba bark extract. See Willow (Salix alba) bark extract Salmiac. See Ammonium chloride Sal mine sulfate. See Protamine sulfate Salol. See Phenyl salicylate SALP. See Sodium aluminum phosphate acidic Sal soda. See Sodium carbonate Salt. See Sodium chloride Sal tartar. See Sodium tartrate Salt cake. See Sodium sulfate Salt of Mohr. See Ferrous ammonium sulfate Saltpeter. See Potassium nitrate Salt of Saturn. See Lead acetate Salt of tartar. See Potassium chlorate Potassium carbonate Salt of tarter. See Potassium chlorate Salt of tin. See Stannous pyrophosphate Salvia. See Sage (Salvia officinalis)... 

Calcium D-pantothenate Cholecalciferol Choline chloride Copper carbonate (ic) Cupric sulfate pentahydrate Ferrous fumarate Magnesium gluconate Magnesium sulfate anhydrous Manganese carbonate Manganese oxide (ous) Manganese sulfate (ous) Menadione DL-Methionine L-Methionine MSG Niacinamide D-Panthenol Potassium iodide Retinol Tocopherol D-a-Tocopherol DL-a-Tocopherol d-o-Tocopheryl acetate animal feed ingredient Casein Com (Zea mays) meal Lactose Sodium sulfate Whey animal feed supplement Ammonium acetate Ammonium perchlorate Calcium phosphate monobasic anhydrous Calcium pyrophosphate Cobalt phosphate (ous)... 

Arsenic acid Sodium nitrate Sodium sulfate clarifier, infant formulas Ferrous sulfate heptahydrate clarifier, liq. soaps Tetrapotassium pyrophosphate clarifier, liqs. 

Ferric pyrophosphate Ferric sodium pyrophosphate Ferrous fumarate Ferrous gluconate Ferrous gluconate dihydrate Ferrous lactate Ferrous sulfate anhydrous Ferrous sulfate heptahydrate Ferrous sulfate monohydrate Fumaric acid D-Gluconic acid Glucose L-Glutamic acid hydrochloride L-Glutamine Glycine Histidine hydrochloride monohydrate L-Histidine Inositol Iron Iron ammonium citrate... 

Calcium carbide Calcium cyanamide Di-iron phosphide Magnesium iron oxide removal Citric acid iron processing Bismuth iron refining Calcium cyanamide iron removal Aluminum sulfate iron source Sodium ferric EDTA iron source, food Ferrous fumarate iron source, infant formulas Ferrous fumarate iron source, nutritional food Ferric pyrophosphate iron source, nutritional infant formulas Ferric pyrophosphate iron source, nutritional pharmaceuticals Ferric pyrophosphate iron source, pharmaceuticals Ferrous fumarate iron source, special dietary food Ferric choline citrate iron, tempering Potassium ferricyanide iron/manganese removal, water treatment Calcium hydroxide iron/steel casting Tellurium... 

Vitamin K Wheat (Triticum vulgare) germ Zinc gluconate Zinc methionine sulfate Zinc oxide Zinc stearate Zinc sulfate Zinc sulfate heptahydrate nutrient, gelatin capsules Retinyi paimitate nutrient, geriatric food Lactose monohydrate nutrient, hair care Sodium pantothenate nutrient, health food Lactose monohydrate Octacosanol nutrient, horticulture Magnesium sulfate heptahydrate nutrient, infant formulas Ferric pyrophosphate Ferrous fumarate Ferrous lactate Ferrous sulfate heptahydrate Inositol... 

The increased absorption above 500 m observed for riboflavin in the presence of a number of transition metals has been confirmed and extended by Radda and Calvin who also noted a similar effect with sodium and magnesium ions. This is likely the result of a perturbation of molecular-orbital energies by the electrostatic effects of a coordinated metal ion, rather than a charge-transfer phenomenon. The shift of the long-wavelength absorption maximum of riboflavin from 447 mjx to 430 mp in the presence of ferrous ion in a pyrophosphate, but not a phosphate or maleate buffer , is unexplained. 

Yoshiaki Miura has published [1] a procedure for the determination of iron and copper in aluminum alloys, using ethylenediamine tartrate (EDT) and potassium pyrophosphate as base electrolyte. As a result of this investigation, polarographic procedures using ethylenediamine tartrate complexes have been developed for the determination of iron (ferrous), nickel, cadmium, and copper, as well as for mixtures of the latter three elements. 

The redox properties of the ferrous-ferric couple vary widely with the complexing ligand (Table III) thus duplicating the potentials of the various cytochromes (Tables V, VII). The more important part of the electron transport activity is the coupling of the redox energy with the formation of pyrophosphate bonds. This is as yet completely unequaled by any model system. 

Reciprocally, since the above reaction is equilibrated, ferrous ions may be titfated by iodine. The reaction (toward the left) is made quantitative by complexation of the formed ferric ions with fluoride or pyrophosphate ions. Then FeFs " and Fe(P207)2 ions are formed, among others. 

---