HPLC Method for Determination of lnositol Tri-, Tetra-, Penta-, and Hexaphosphates in Foods and Intestinal Contents

A HPLC method was developed for separation and quantitative determination of inositol tri-, tetra-, penta-, and hexaphosphates. The method included extraction of inositol phosphates with HCl, separation of the inositol phosphates from the crude extract by ion-exchange chromatography, and ion-pair Cl8 reverse phase HPLC analysis using formic acid/methanol and tetrabutylammonium hydroxide in the mo, bile phase. The inositol 3-6 phosphates of raw and extruded bran, soy flour, and intestinal contents were determined by HPLC and compared to phytate determinations by two iron precipitation methods. lnositol 3-5 phosphates were found in extruded products and intestinal contents. The HPLC method was rapid and gave reproducible values, which differed from those obtained by the precipitation methods in some samples