High performance liquid chromatographic method to determine natural folate (5-methyltetrahydrofolate) and added folic acid content in food matrices.

摘要

5-Methyltetrahyrofolate (5-MeTHF) was analyzed in food samples using reverse phase chromatography, a gradient mobile phase of 33 mM phosphate buffer (pH 2.3) and acetonitrile, a flow rate 0.8ml/min, and fluorometric detection. For natural folate analysis, procedures were optimized for thermal extraction, enzymatic deconjugation, and clean up protocol using a strong anion exchange columns (SAX) and affinity chromatography using folate bind protein (FBP) columns. SAX column clean up did not yield clearly resolved peaks for broccoli. However, affinity column clean up yielded well resolved peaks. While the peak areas were small, they were still quantifiable. The 5-MeTHF content in spinach assayed using affinity chromatography for sample clean-up was lower than the concentration determined using Solid phase extraction (SPE) columns (15.66+/-0.83 vs. 98.92+/-1.24 mug/100 g). Results from SAX column clean up were closer to LCMS values than that of FBP clean up values. (Abstract shortened by UMI.)