RAPID AND SIMULTANEOUS ANALYSIS OF FREE STEROLS, TOCOPHEROLS, AND SQUALENE IN EDIBLE OILS BY COUPLED REVERSED-PHASE LIQUID-CHROMATOGRAPHY GAS-CHROMATOGRAPHY

On-line coupling of reversed-phase liquid chromatography and gas capil lary chromatography (RPLC-GC) using a programmed temperature vaporizer (PTV) as interface is used for the direct and simultaneous analysis o f free sterols, tocopherols, and squalene of edible oils by direct inj ection (that is, without the need for prior enrichment of the sample). The proposed method allows large volume fractions of water methanol e luents to be transferred into the GC system, 2000 mu L/min being the s peed of sample introduction. The overall procedure including LC presep aration, transfer from LC to GC, and GC analysis takes <1 h.