DETERMINATION OF ISOMERS OF INOSITOL MONOPHOSPHATES TO HEXAPHOSPHATESIN SELECTED FOODS AND INTESTINAL CONTENTS USING HIGH-PERFORMANCE ION CHROMATOGRAPHY

A sensitive high-performance ion chromatography (HPIC) method for sepa ration and quantitative determination of inositol mono- to hexaphospha te (IP1-IP6) isomers in selected foods and intestinal contents is desc ribed. The method includes extraction of samples with HCl, separation of the inositol phosphates from the crude extract by anion-exchange ch romatography, separation on highperformance ion-exchange columns with gradient elution in two combined HPIC systems, and detection using eit her postcolumn reaction and UV detection (system 1) or chemically supp ressed conductivity detection (system 2). IP2-IP6 in samples were dete rmined on the first system, which also separated isomers of IP4 and IP 5. Fractions of IP1-IP3 from the first system were transferred to the second system after some additional sample preparation and analyzed fo r isomers, The applicability and sensitivity of the method are illustr ated by measuring the content of inositol phosphates in foods, ileal c ontents, and feces of human balances.