INFLUENCE OF RELATIVE HUMIDITY ON THE REACTION PRODUCTS OF PHOSPHATES AND NONCRYSTALLINE HYDROXIDES OF ALUMINUM AND IRON.

Aluminum and iron in noncrystalline constituents in soils play a major role in phosphate fixation. Noncrystalline aluminum and iron hydroxides have often been used as model materials of these soil constituents. This infrared spectroscopic method was useful for identifying the reaction product especially when it was present as a surface complex or as a material amorphous to X-rays. If the product was a mixture of several components, subtracting the spectrum of one component from that of the mixture allowed the other component to be identified.