Determination of phytate in high molecular weight, charged organic matrices by two-dimensional size exclusion-ion chromatography

A two-dimensional chromatography method for analyzing phytate or other ionic targets in matrices containing high molecular weight, charged organic species is described. Prior to quantification by anion exchange chromatography, the sample matrix was prepared by size exclusion chromatography, which removed the majority of the matrix. Quantification of phytate on the AS11-HC was sensitive (0.25 µM, 0.17 mg/l) and reproducible (4.6% RSD) allowing this method to provide baseline separation of phytate from a manure extract within 14 min. The method is simple, requiring only sample filtering, reproducible (between-run variation 5% RSD) and linear from 0.38 to 76 µM (0.25–50 mg/l). The method is suitable for routine determination of phytate in high organic matrices such as manure extracts.