Direct analysis of vitamin A, vitamin E, carotenoids, chlorophylls and free sterols in animal and vegetable fats in a single normal-phase liquid chromatographic run.

The present method was optimized and validated to enable quantification of more than twenty compounds from four chemical classes of important lipid substances, including vitamin E and A derivatives, sterols and chlorophylls. After lipid dissolution in the mobile phase, chromatographic separation is accomplished with the newest generation of ultrapure unbounded fully porous silica particles and, finally, target analytes are quantified by diode-array tandem fluorescence detection. A broad working range was achieved for most compounds (r > 0.999), with selectivity/specificity confirmed for each analyte by high resolution factors. Limits of detection and quantification were generally as low as a few nanograms per milliliter. The method also showed adequate repeatability and intermediate precision (RSD < 5%) and proved to be very accurate (89-116 %) when applied to the analysis of several vegetable and animal fats. The proposed method is a faster, cost-effective and environmental-friendly alternative for routine analyses in the food quality control field, providing extensive information in one single injection, without sample pre-treatment. Moreover, it preserves the identity of the sample components, thus enabling fingerprints for authenticity purposes.