High-performance liquid chromatography of phosphatidylcholine and sphingomyelin with detection in the region of 200 nm.
A sensitive method for the separation of phosphatidylcholine and sphingomyelin by high-performance liquid chromatographic analysis is described. The elution of the phospholipids from a microparticulate (10 mum) silica-gel chromatographic column was monitored with an ultraviolet spectromonitor at 203 nm. Acetonitrile/methanol/water (65:21:14, by vol.) was used as the solvent. It was shown by using synthetic phosphatidylcholines of knowm fatty acid composition and of varying degree of unsaturation that the absorption at 203 nm was primarily due to the isolated double bonds and the response measured varied with the degree of unsaturation. Approx. 1 nmol of phosphatidylcholine, containing at least one double bond per molecule, can be detected. The amounts of phosphatidylcholine and sphingomyelin could be determined by high-performance liquid chromatography and ultraviolet absorption if the apparent extinction coefficient of the material analyzed was established. Alternatively, peaks were collected and the phospholipids were determined by the analysis of phosphorus. The analysis of phosphatidylcholine and sphingomyelin present in the lipid extracts from animal tissues, blood and amniotic fluids were made without interference from other phospholipids or ultraviolet-absorbing material. The method described here is complementary to the high-performance liquid chromatographic method described previously for the analysis of ethanolamine-containing phosphoglycerides and serine-containing phosphoglycerides [Jungalwala, Turel, Evans and McCluer (1975) Biochem. J. 145, 517-526].