High performance liquid chromatographic analysis of molecular species of phosphatidylcholine--development of quantitative assay and its application to human bile.

In this paper we propose a novel, rapid and simple high-performance liquid chromatographic (HPLC) method for the identification and quantitation of individual phosphatidylcholine (PC) molecular species from natural mixtures. To overcome difficulties deriving from the lack of adequate standards and from the variability of the responses to UV spectrophotometric detectors currently used in HPLC analysis, we first fractionated and quantitated the major molecular species of a commercial egg PC by means of a preparative column. The identification of PC molecular species was confirmed by gas-liquid chromatographic analysis of fatty acids. We employed the fractions recovered from preparative HPLC to determine the detector calibration factors of the individual molecular species separated using an analytical, high-speed, reversed-phase HPLC column. The proposed method seems to be adequate for the analysis of PC from many biological sources. Its application to the analysis of human hepatic and gallbladder biliary PC is shown.