Triacylglycerol Positional Isomers Research Articles

Analysis of triacylglycerol positional isomers in food products as brominated derivatives by high-performance liquid chromatography coupled with a flame ionization detection

Reversed-phase HPLC resolution and HPLC–flame ionization detection quantitation of model triacylglycerol positional isomer pairs (important in the study of food formulation lipids) after facile conversion to brominated derivatives is reported. The positional isomers in the triacylglycerol pairs were at least 98% resolved from each other during reversed-phase HPLC. Triacylglycerol quantitation obtained by HPLC–flame ionization detector was checked against standard positional isomer pairs known by mass. The flame ionization detection area percent gave absolute error range of 0.3–1.6% per triacylglycerol.

Identification of triacylglycerol positional isomers present in vegetable oils by high performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry

High performance liquid chromatography in conjunction with atmospheric pressure chemical ionization mass spectrometry (HPLC/APCI-MS) enables the positional isomers of individual triacylglycerols in mixtures to be identified. Application of HPLC/APCI-MS to the analysis of soybean oil allowed thirty nine triacylglycerols and seven diacylglycerols to be positively identified. The compounds present were quantified and the distribution of fatty acids in the ‚-position calculated. This distribution compared favourably with that obtained using a more conventional regiospecific lipase degradation of the oil. A survey of the acylglycerol components of a range of vegetable oils (blackcurrant, blue poppy seed, evening primrose, extra virgin olive, hazelnut, maize and rapeseed) carried out using HPLC/APCI-MS is reported. © 1997 by John Wiley & Sons, Ltd.

Analysis of triacylglycerol positional isomers by silver ion high performance liquid chromatography

AbstractSilver ion chromatography, utilizing two commercially available HPLC columns connected in series, was used to separate a variety of triacylglycerol positional isomers. The isomers had a fatty acid composition of ABA and AAB, where A and B were fatty acids containing zero to three double bonds. Isocratic solvent systems of 0.5% to 1.0% acetonitrile in hexane were used to separate the triacylglycerol isomers. This methodology can be used to rapidly determine the isomeric purity of synthesized or isolated triacylglycerols and to isolate specific positional isomers.

High-Performance Liquid Chromatographic Analysis of Positional Isomers of Dipalmitoolein in Palm Oil as Halogen Adducts

High performance liquid chromatographic separation of two positional triacylglycerol isomers of 1, 3-dipalmitoy1-2-oleoylglycerol (POP) and 1, 2-dipalmitoyl-3-oleoyl-rac-glycerol (PPO) as bromine or ICl adducts was carried out on a reversed stationary phase column packed with 3 μm particles of LiChrospher 100CH-18. Good separation of the triacylglycerol positional isomers required about 130 min as the bromine adduct using acetone/acetonitrile (8 : 2 vol/vol) as the mobile phase. Palm oil was analyzed by this method under similar conditions and the proportion of PPO to POP in palm oil was determined.