Amniotic fluid phospholipids measured by continuous-development thin-layer chromatography.

We describe a one-dimensional thin-layer chromatographic system for separation of amniotic fluid phosphatidylcholine, sphingomyelin, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, and phosphatidylethanolamine in amniotic fluid. We utilize short-bed continuous development and "high performance" thin-layer chromatography. Phospholipids are detected with an antimony molybdate staining reagent and quantitated by transmittance densitometry. This system is more sensitive to changes in lecithin/sphingomyelin ratios than are planimetric evaluations.