A new liquid chromatography method with charge aerosol detector (CAD) for the determination of phospholipid classes. Application to milk phospholipids

A new rapid method for the quantitative analysis of five classes of phospholipids (PLs) (phosphatidylcholine—PC, lysophosphatidylcholine—LPC, phosphatidylethanolamine—PE and phosphatidylserine—PS and phosphatidylinositol—PI) using liquid chromatography with charge aerosol detector (CAD) is described. The separation of the compounds of interest was achieved on a diol stationary phase with a mobile phase consisting of 13% HCOOH, hexane and 2-propanol in 19 min elution program, including 10 min equilibration of the column. The method was applied to characterize the phospholipid fractions of cow milk. PLs present in cow milk were separated by solid-phase extraction (SPE) procedure with Si cartridges before LC analysis with recovery ranging from 95.3% to 104.4%. The use of CAD detection of the eluted compounds was precise, linear and sensitive.