Analysis of Milk Phospholipids by Chromatography and Infrared Spectrophotometry

Abstract

Milk phospholipids were fractionated into the major phospholipid classes by successive elution from a silicic acid column with chloroform, acetone, methanol (20% and 40%) in chloroform, and methanol. Each fraction was analyzed by infrared spectrophotometry and by chemical methods. Potassium bromide disk spectra of milk cerebrosides, cephalins, lecithins, and sphingo-myelins are presented and compared with pure reference compounds. Concentrations of each class were calculated from specific bands measured either in chloroform or in carbon disulfide solutions. Respective weight percentages of cerebrosides, cephalins, lecithins, and sphingomyelins were: 6, 35, 32, and 24. Evidence is given for the presence of minor amounts of other constituents, including carbohydrate-containing phospholipids, lysolecithins, and unidentified lipids. Advantages and limitations of the method at its present state of development are discussed.