Analysis of sterols in vegetable oils using off-line SFC/capillary GC-MS

The analysis of sterols in vegetable oils by off-line SFC followed by capillary GC-MS is described. The fractionation of the sterols from the complex oil matrix is achieved by SFC on aminopropyl silicagel in less than 8 minutes. Injection and collection of the sterol fraction is fully automated and time controlled. The sterols are analysed without derivatisation by capillary GC-MS. Identification is performed by full scan electron ionisation and quantitation is carried out by extracted ion chromatography at m/e 107, with cholesterol as internal standard. The analyses of the sterols from the sunflower oil and two olive oils illustrate the possibilities of the method.