Quantitative release of fatty acids from lipids by a simple hydrolysis procedure.

Glycerolipids and sphingolipids are hydrolyzed with 0.5 M HCl in acetonitrile-water 9:1 (by vol) for 45 min at 100 degrees C or 4 hr at 70 degrees C. After hydrolysis, free fatty acids (FFA) are recovered in chloroform and separated by thin-layer chromatography. More than 95% of the radioactivity from labeled phospholipids is recovered as FFA, and more than 97% of the lipid phosphorus is recovered as water-soluble phosphate. The yields of FFA, including polyunsaturated acids, after hydrolysis are as good as or better than those obtained for methyl esters using methanolysis catalyzed by acid, alkali, or BF3. High recoveries of FFA from glycerophospholipids, sphingomyelin, and neutral glycerides are attained. The procedure is quantitative, simple, inexpensive, and produces no methyl esters as secondary products.