Determination of related substances in egg yolk lecithin by HPLC-CAD and characterization of its profiling by HPLC-Q-TOF-MS.

A high-performance liquid chromatography (HPLC) method has been developed for the determination of related substances in egg yolk lecithin. Chromatographic separation was achieved using a gradient elution on a Waters Xbridge HILIC column maintained at 35 ℃. Mobile phase A was composed of water-acetonitrile (80:20, v/v, containing 5 mM ammonium acetate), and mobile phase B was composed of acetonitrile. Analytes were monitored by a charged aerosol detector (CAD) at 50 ℃. The novel HPLC-CAD method was selective and sensitive for the determination of related substances in egg yolk lecithin in its commercial bulk batches. It was also successfully validated by the International Council for Harmonisation (ICH) guidelines. The method will be a renewal of an old Chinese Pharmacopoeia method (2020 edition). Moreover, quadrupole time-of-flight mass spectrometry (Q-TOF-MS) was integrated with HPLC to investigate phospholipid species in egg yolk lecithin. This work provides comprehensive composition profiles of egg yolk lecithin, thereby accelerating the quality control, development, and application of egg yolk lecithin.