The linearity was assessed from the calibration curves obtained at five concentration levels of each compound: 0.5e10 mg/mL for retinol, 2.5e20 mg/mL for g and d tocopherols, 2e40 mg/mL for a tocopherol, 50e250 mg/mL for tocopheryl acetate, 10e100 mg/mL for retinyl palmitate, and 1e40 mg/mL for b-carotene.