Validation of a method for simultaneous quantification of total carotenes and tocols in vegetable oils by HPLC

A normal-phase HPLC method for analysis of carotenes, tocopherols and tocotrienols has been developed and validated. In this work we presented a modification to the official AOCS method for analysis of tocols which allowed simultaneous quantification of the three groups of compounds, including carotenes. Analytes were separated using a gradient mobile phase (hexane and isopropanol) and with a gradient flow rate (1–2 mL min⁻¹). The column effluent was monitored by Photo Diode Array detector (PDA) set at 292 nm (tocols) and 455 nm (β-carotene) and by fluorescence detector set at an excitation wavelength of 290 and 330 nm emission. Inter- and intra-run accuracies and precision of the analytical method were better than ±15%. The lower limit of quantification was 5.0 mg L⁻¹ for the tocols and 0.1 mg L⁻¹ for carotenes. The method has been applied for the quantification of these compounds in Amazon oils.