Determination and purification of sesamin and sesamolin in sesame seed oil unsaponified matter using reversed‐phase liquid chromatography coupled with photodiode array and tandem mass spectrometry and high‐speed countercurrent chromatography

In Asian countries, sesame seed oil unsaponified matter is used as a natural food additive due to its associated antioxidant effects. We determined and purified the primary lignans sesamin and sesamolin in sesame seed oil unsaponified matter using reversed‐phase liquid chromatography coupled with photodiode array and tandem mass spectrometry and high‐speed countercurrent chromatography. Calibration curves showed good correlation coefficients (r² > 0.999, range 0.08 and/or 0.15 to 5 μg/mL) with a limit of detection (at 290 nm) of 0.02 μg/mL for sesamin and 0.04 μg/mL for sesamolin. Sesame seed oil unsaponified matter contained 2.82% sesamin and 2.54% sesamolin, respectively. Direct qualitative analysis of sesamin and sesamolin was achieved using quadrupole mass spectrometry with positive‐mode electrospray ionization. Pure (>99%) sesamin and sesamolin standards were obtained using high‐speed countercurrent chromatographic purification (hexane/ethyl acetate/methanol/water; 7:3:7:3). An effective method for determining and purifying sesamin and sesamolin from sesame seed oil unsaponified matter was developed by combining these separation techniques for standardized food additives.