[Using ultra performance liquid chromatography]

An analytical method based on ultra performance liquid chromatography has been developed for the simultaneous determination of 15 hormones (triamcinolone, hydrocortisone, prednisone, cortisone, 6a-methylprednisolone, betamethasone, dexamethasone, prednisolone acetate, hydrocortisone acetate, estriol, beta-estradiol, estrone, diethylstilbestrol, testosterone and progesterone) in cosmetics. Various cosmetic samples were extracted with methanol under ultrasonication, and then cleaned up by a Oasis HLB solid phase extraction cartridge. The 15 hormones were separated and detected within 6 min on a Waters ACQUITY UPLC BEH C18 column (1.7 microm, 2.1 mm x 50 mm) by gradient elution with acetonitrile and water system. In the range of 1-25 ng, the calibration curves of 15 hormones showed good linearity with the correlation coefficients larger than 0.9995. The mean recoveries at the three spiked levels (2, 10, 20 mg/kg) were 88.2%-102.4% with the relative standard deviations of 1.6%-7.4%.