Simultaneous determination of α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, sesamin, sesamolin, sesamol, and asarinin in sesame oil by normal-phase high performance liquid chromatography

A simple and fast normal-phase high performance liquid chromatography method for simultaneous detection of α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, sesamin, sesamolin, sesamol, and asarinin in sesame oil (SO) was investigated. Conditions were a silica gel column as the separation unit, n-hexane and tetrahydrofuran (93:7, v/v) as the mobile phase, isocratic elution, a flow rate of 0.8 mL/min, column temperature of 30 °C, and florescence detector with excitation and emission wavelengths of 295 and 330 nm. SO samples were directly dissolved in n-hexane for HPLC analysis. Results showed that the method performed wide linear ranges and good linearity (0.27–100.0 μg/mL, R2 > 0.9996), low limits of detection (0.09–0.16 μg/mL) and quantification (0.27–0.41 μg/mL), good precision and accuracy (biases of <2.83 % and relative standard deviations of <3.77 %), good separation performance [resolution factor (1.66–6.20), separation factor (1.11–3.94), retention factor (1.08–1.42), and height of theoretical plates (0.01–0.04 mm)], and satisfactory recoveries (87.3–109.8 % for SO and 96.5–106.9 % for lard). The method was successfully applied for the simultaneous determination of the eight analytes in eleven SO samples.