High performance thin layer chromatography of disaturated phosphatidylcholines in amniotic fluid

A method for isolation and quantification of disaturated phosphatidylcholines in amniotic fluid is described. Phospholipids are extracted with chloroform/methanol, and the unsaturated lipids are reacted with osmium tetroxide. The saturated phospholipids are separated on high performance thin layer silica gel plates with a concentrating zone. The coloured lipid spots are quantified by reflectometric scanning and compared with standards. The between-day coefficient of variation is 4-5% for values near the lower reference limit. Total analysis time for an amniotic fluid sample is about 2 h.