Simplified quantitative determination of phospholipids in amniotic fluid, alveolar lavages and milk using high performance liquid chromatography (HPLC).

A one step HPLC method for the determination of the main phospholipids, phosphatidylglycerol (PG), phosphatidylinositol (PI), phosphatidylethanolamine (PE), phosphatidylcholine (PC), sphingomyelin (SP) and lysolecithin (LL) in amniotic fluid, milk, tracheal secretion, lung lavages, gastric aspirates, infant formulas and some other human and animal media has been developed. Quantitation occurs automatically using computer calculation and lysolecithin as an internal standard. Detection limits are at about 0.2 micrograms/100 ml but may rise to about 0.3 micrograms/100 ml in cases of high fat levels or other interfering compounds. Recovery rates measured in amniotic fluid fluctuate around the 100% level. Time required for a single analysing including a blank run and a calibration standard solution measurement amounts to about two hours. In series analysis 12 samples per day can be examined, while the required time per sample is reduced to 40 minutes. As phospholipids carry an important function in many spheres of medicine, the improvement in specific quantitative determination of these compounds is of great importance.