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An HPLC method was optimized to analyze soybean phospholipids. It uses a silica column with W detection at 210 nm, and amobile phase consisting ofhexane,isopmpanol and water. Separation isachieved by keeping the hexane toisopropanolratioconstant andvaryingthewaterconcentrationina gradient elution program. Components in the HPLC chromatogram were identified by comparison with retention times of authentic compounds.The

Analysenberichtrationen, die nicht in der Methode erwahnt sind, im Protokoll aufmfiihren.Das Ergebnis der Bestirnmung ist unter Hinweis auf diese Methodeund das angewandte Temperierverfahren anzugeben. Femer sind alle Angaben zur Identifizierung der Probe, eine Filtrationgem.5 und alle ope-Eingegangen a m 19. Dezember 1985.A high pelformance liquid chromatographic (HPLC) method has been developed to analyze oxidative and polymerized decomposition products in commercial vegetable oils and heated fats. The oil was passed through a SEP-PAK where the minor constituents were concentrated. The SEP-PAK was eluted with hexane-ether 1 : 1 (v/v), and 2-pmpanol. The first eluate contained unsaponifiables and neutral lipids, and the second eluate contained the more polar oxidative and polymerized decomposition products. The second eluate was analyzed by normal phase HPLC. Five commercial vegetable oils were analyzed, and similarities and differences were obsewed. Four soybean oil samples from different manufacturers also showed differences. Soybean oil heated at 1 8 5 O C was collected periodidly and analyzed. As the heating time increased, the oxidation and polymerization products also increased. Used fTying fat samples from a commercial fried chicken manufacturer were analyzed.The frying oil quality reached an equilibrium during three days of operation, because the oil lost in frying was replenished daily with fresh shortening.