Development of a Simultaneous Normal-Phase HPLC Analysis of Lignans, Tocopherols, Phytosterols, and Squalene in...

The objective of this study was to develop a simultaneous analytical method for the determination of lignans, tocols, phytosterols, and squalene using high-performance liquid chromatography coupled with a diode array and fluorescence detector (HPLC-DAD-FLD). The method employed a Vertisep^TM UPS silica HPLC column (4.6 × 250 mm, 5 µm) with a mobile phase mixture of n-hexane/tetrahydrofuran/2-propanol. This approach enabled the simultaneous analysis of ten compounds within 22 min. The linear correlation (R²) exceeded 0.9901. The limit of detection (LOD) and limit of quantitation (LOQ) were up to 0.43 µg mL^-1 for lignans and tocopherols and up to 326.23 µg mL^-1 for phytosterol and squalene. The precision and accuracy of the intra-day and inter-day variation were less than 1.09 and 3.32% relative standard deviations (RSDs). Furthermore, the developed method was applied for the analysis of targeted compounds in twenty-eight sesame oil samples (1775-8965 µg g^-1 total lignans, 29.7-687.9 µg g^-1 total tocopherols, 2640-9500 µg g^-1 phytosterol, and 245-4030 µg g^-1 squalene). The HPLC method that has been developed was proven to be a reliable and effective tool for the determination of those functional compounds among sesame oil samples.