Determination of sex hormones in cosmetic products by magnetically stirring extraction bar liquid–liquid microextraction coupled with high performance liquid chromatography

Abstract

Magnetically stirring extraction bar liquid–liquid microextraction (MSEBLLME) was applied to the extraction of 8 hormones, including 19-nortestosterone (nandrolone), testosterone, estrone, 17-α-hydroxyprogesterone, medroxyprogesterone, megestrol acetate, progesterone and testosterone propionate (androlin), in cosmetic products. The magnetic stirring extraction bar was prepared by inserting a stainless steel wire into the hollow fiber and impregnating the ionic liquid into the pores of the fiber wall. The bar can be used to both stir the sample solution and to extract the analytes. The present method makes it possible for complete extraction, clean-up and pre-enrichment processes to occur in one step. Several experimental parameters, including the type of ionic liquid, the immersion time of the hollow fiber, the pH value, and the concentration of NaCl, were investigated and optimized. The analytes in the extract were determined by high performance liquid chromatography. Under optimal experimental conditions, good linearity was observed. The limits of detection and quantification were in the range of 0.91–1.01 ng mL⁻¹ and 3.04–5.97 ng mL⁻¹, respectively. Recovery of the analytes was in the range of 91.3–106.2% with the relative standard deviations ranging from 0.17% to 5.47%. The results showed that the present method is suitable for the determination of hormones in cosmetic samples.