Liquid chromatographic analysis of milk phospholipids with on-line pre-concentration.

Two methods have been developed for the analysis of bovine milk phospholipid (PL) classes by NP-HPLC with evaporative light scattering detection. In the first method, a PVA-Sil guard column was used for the rapid determination of the major milk PL, phosphatidylethathanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM). In the second method, the guard column was used to pre-concentrate the PL, which were then transferred on-line onto a PVA-Sil analytical column by the use of column switching valves. This enabled separation of complete milk PL, including phosphatidylinositol (PI), phosphatidylserine (PS) and lysophosphatidylcholine (LPC).