B6 vitamer analysis in human plasma by high performance liquid chromatography: a preliminary report.

An extraction procedure that can be used successfully with a high performance liquid chromatography sample clean-up and analytical method is outlined for the determination of B6 vitamer and pyridoxic acid concentrations in human plasma. The method is a modification of ones developed for food and animal tissue investigations. Chromatographic traces, relatively clean of interfering compounds are obtained. The method has the advantage of speed and reproducibility and yields recoveries of from 90 to 100% for all vitamers and pyridoxic acid.