Abstract
The increasing interest in antioxidant properties of cereal and cereal‐based products has prompted the development of a simple and reliable HPLC method for the simultaneous determination of important phytochemicals like tocopherols (T), tocotrienols (T3) and carotenoids. Separation was carried out on a Nucleosil 100 C~18~ column, 5 μm (250 mm×4.6 mm) thermostated at 25°C, using a linear gradient elution system starting with methanol and ending with a mixture of methanol–isopropanol–acetonitrile. All separated compounds including the internal standard (α‐tocopherol acetate) were eluted within 16 min and detected by dual detection: fluorescence for tocopherols and tocotrienols at 290 nm excitation and 320 nm emission and UV–vis photodiode array detection for lutein and β‐carotene at 450 nm. Detection limits ranged from 0.2 μg/g (β‐carotene) to 1.60 μg/g (α‐tocopherol). The intra‐ and inter‐assay coefficients of variation were calculated by using cereals with different levels of lipophilic antioxidants. The extraction method involved sample saponification and clean‐up by solid‐phase extraction (SPE). The extraction recoveries obtained using OASIS HLB SPE cartridges and dichloromethane as eluent were in the range of 90.2–110.1%, with RSD lower than 10%. The method was successfully applied to cereals: durum wheat, bread wheat, rice, barley, oat, rye, corn and triticale.