Cereal Chem 59:525 - 528.  |  VIEW ARTICLE
Structural Model for Ferric Phytate: Implications for Phytic Acid Analysis.

D. B. Thompson and J. W. Erdman, Jr. Copyright 1982 by the American Association of Cereal Chemists, Inc. 

Numerous phytic acid assays rely on the precipitation of phytate with ferric ion. Work with the iron- phosphorus molar ratio of the ferric phytate precipitated from soybean extracts indicated that this ratio was subject to variation. Further investigation regarding the precipitate led to a molecular hypothesis that may help to explain the variable nature of the molar ratio of this precipitate. Phytic acid assays that rely on analysis of iron from the ferric phytate precipitate are not recommended.