A preferred solvent system for high-performance liquid chromatographic analysis of soybean phospholipids with evaporative light-scattering detection

Normal-phase high-performance liquid chromatography separations of phospholipids (PL) depend heavily on the variation in mobile phases. Incorporation of pure tetrahydrofuran to a mobile phase of chloroform, methanol, and ammonium hydroxide improved the separation of polar phospholipids. However, impurities were often found to be present in tetrahydrofuran that caused severe peak interferences with PL analytes. The use of a common chromatographic solvent tert.-butyl methyl ether, in lieu of tetrahydrofuran in mobile phases, eliminated problems associated with solvent contamination and yielded reproducible results. The modified method has been applied for the quantitative analysis of phospholipids in crude soybean oils.