Isolationof the Acidic PhospholipidPhosphatidyiglycerolfrom PulmonarySurfactantby Sorbent

Aminopropyl solid-phase columns can be usedfor phospho-lipid fractionation. A method has been developed to elute the acidic phospholipid phosphatidylglycerol (PG) separately, and it is applicable to both standard (phospho)Iipid mixtures and pulmonary surfactants. The simplicity, rapidity, and high recovery make this method of isolating PG superior to other chromatographic procedures. Several enzymatic procedures have been developed for determining the amount of surfactant phosphatidyiglycerol (PG) in amniotic fluids. Some of these enzymatic findings disagreed with results obtained after thin-layer chromatog-raphy (TLC) (1, 2) and, especially when the amount of PG is approximately the same as that of lecithin (3), one has to doubt the enzymatic PG results. Usually, the amount of PG is determined by phospholipid-phosphorus assay, but then PG has to be isolated first. Several techniques are available, but TLC is time-consuming and Thigh-performance ” liquid chromatography requires rather expensive equipment. The neutral and acidic phospholipids(including PG) can be separated by anion-exchange chromatography (4, 5), but these methods require large volumes of solvents. Relatively small volumes of solvents are, however, needed if solid-phase columns are used for ion-exchange chromatography. This note describes a “<10-minute ” procedure for isolating PG by using solid-phase aminopropyl columns. The amount of PG can then be determined