HPLC Method for Determination of inositol Tri‐, Tetra‐, Penta‐, and Hexaphosphates in Foods and Intestinal Contents

Abstract

ABSTRACT 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 HCI, separation of the inositol phosphates from the crude extract by ion‐exchange chromatography, and ion‐pair C18 reverse phase HPLC analysis using formic acid/methanol and tetrabutylammonium hydroxide in the mobile 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. Inositol 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.