Phosphorus compounds containing iron, organic

Bioavailability of Iron From Organic Compounds Containing Both Phosphorus and Iron... 

The vast majority of organic compounds contain carbon, hydrogen, oxygen and nitrogen. Other t es of atoms can be included to form even more compounds. These can contain atoms like phosphorus, sulphur (e.g. thiamine, vitamin B ), magnesium (e.g. chlorophyll) and iron (e.g. haemoglobin). 

In catalytic incineration, there are limitations concerning the effluent streams to be treated. Waste gases with organic compound contents higher than 20% of LET (lower explosion limit) are not suitable, as the heat content released in the oxidation process increases the catalyst bed temperature above 650 °C. This is normally the maximum permissible temperature to which a catalyst bed can be continuously exposed. The problem is solved by dilution-, this method increases the furnace volume and hence the investment and operation costs. Concentrations between 2% and 20% of LET are optimal, The catalytic incinerator is not recommended without prefiltration for waste gases containing particulate matter or liquids which cannot be vaporized. The waste gas must not contain catalyst poisons, such as phosphorus, arsenic, antimony, lead, zinc, mercury, tin, sulfur, or iron oxide.(see Table 1.3.111... 

Organic constituents that may be found in ppb levels in WP/F smoke include methane, ethylene, carbonyl sulfide, acetylene, 1,4-dicyanobenzene, 1,3-dicyanobenzene, 1,2-dicyanobenzene, acetonitrile, and acrylonitrile (Tolle et al. 1988). Since white phosphorus contains boron, silicon, calcium, aluminum, iron, and arsenic in excess of 10 ppm as impurities (Berkowitz et al. 1981), WP/F smoke also contains these elements and possibly their oxidation products. The physical properties of a few major compounds that may be important for determining the fate of WP/F smoke in the environment are given in Table 3-3. 

The bioavailability of iron from several organic phosphorus-containing compounds appears to be good. The iron in ferripoly-phosphate protein powder (13) and ferric glycerol phosphate Q, 6) was found to be 92-100% as bioavailable as ferrous sulfate in heme repletion assays with anemic rats and chicks. Morris and Ellis (14) have reported that the iron in monoferric phytate was utilized by rats as well as the iron in ferrous ammonium sulfate. While Lipschitz, et al. (15) have reported that dogs absorbed radio-labelled iron from a small dose (1.5 mg iron) of monoferric phytate one-half as well as they absorbed iron from ferrous sulfate. 

Not all organic compounds that contain both phosphorus and iron are good sources of iron. Numerous investigators have demonstrated that the iron in egg yolk was less bioavailable than the iron in reference salts to both men (16, 17) and animals (18-22) This effect of egg yolk on the utilization of iron by animals is due to phosvitin, a glyco-protein in egg yolk (23, 24). This protein contains about 135 phosphoserine groups per molecule. 

---