Investigations on Extraction of Rat Plasma Phospholipids.

The poor recovery of phospholipid when rat plasma was extracted into petroleum ether after primary extraction with ethanol: ether was shown to be a function of the extraction method, since complete recovery of the phosphorus was obtained after initial extraction with chloroform:methanol. When the petroleum ether-soluble and -insoluble phosphorus fractions obtained from the ethanol: ether extraction were fractionated into separate phospholipid classes, the phosphorus recovered and the fatty acid composition of the phospholipids were similar. Thus the petroleum ether-insoluble phosphorus was intact phospholipid and was not a specific phospholipid, such as sphingomyelin or lysolecithin.