Determination of Estrogens in Pork and Chicken Samples by Stir Bar Sorptive Extraction Combined with High-Performance Liquid Chromatography-Ultraviolet Detection

A poly(dimethylsiloxane) (PDMS)/beta-cyclodextrin (beta-CD)/divinylbenzene (DVB)-coated stir bar was prepared by the sol gel technique for the stir bar sorptive extraction (SBSE) of four estrogens from animal-derived foods, followed by liquid desorption (LD) and high-performance liquid chromatography ultraviolet (HPLC-UV) detection. The influence of the coating composition on SBSE of target estrogens was investigated by an orthogonal experiment design, and the prepared PDMS/beta-CD/DVB-coated stir bars show good reproducibility. Under the optimal experimental conditions, the limits of detection (S/N = 3) of the developed PDMS/beta-CD/DVB SBSE-LD-HPLC-UV method were 0.21-1.6 mu g/L for the target estrogens with enrichment factors of 19-51-fold, the dynamic linear range was 2-2000 mu g/L, and the relative standard deviations of the method ranged from 6.0% to 9.7% (n = 8, c = 100 mu g/L) and from 8.4% to 11.7% (n = 8, c = 10 mu g/L). The developed method was simple, sensitive, and selective and was successfully applied to the analysis of estrogens in pork and chicken samples.