Abstract: An efficient method for analyzing seven sexual hormones (estradiol-17β, estriol, estrone, testosterone, methyl-testosterone, progesterone and diethylstilbestrol) in essential oil by high performance liquid chromatography was developed. The samples were dissolved in n-hexane, then extracted with 90% methanol solution. The n-hexane layer was discarded and the methanol layer was cleaned-up twice with n-hexane. The target compounds were separated on an XTerraRP18 column (250 mm×4.6 mm, 5 μm) using water-methanol-acetonitrile (50:30:20, v/v/v) as mobile phase in isocratic mode, and detected by a diode array detector (DAD) and a fluorescence detector (FLD). The flow rate was 1.0 mL/min. Estriol, estradiol-17β, estrone, diethylstilbestrol were detected at 197 nm; progesterone, testosterone, methyl-testosterone were detected at 240 nm; estriol, estradiol-17β, estrone were detected with the fluorescence detector simultaneously, the excitation and emission wavelengths were 280 nm and 310 nm, respectively. The average spiked recoveries for seven sexual hormones were above 93.0% except that of progesterone was 79.5%. The relative standard deviations of seven sexual hormones were from 0.90% to 1.89%. The linear ranges of the determination were from 0.010 mg/L to 1.0 mg/L. The method is simple and accurate for simultaneously analyzing the seven sexual hormones in essential oil.

Key words: diode array detection (DAD), essential oil , fluorescence detection (FLD), sexual hormones, high performance liquid chromatography (HPLC)