Development and Application of Dispersion Solid-Phase Extraction for Estrogens in Aquatic Animal Samples

A simple, fast, robust, sensitive, and specific method for the confirmation and quantification of four kinds of estrogens, including 17 beta-estradiol (E2), estriol (E3), 4-hydroxyestradiol (4-OHE2), and 2-methoxyestradiol (2-MeOE2), in fortified and incurred fish and shrimp flesh samples was developed. The method used simple extraction of a sample with acetonitrile, dispersive solid-phase extraction (dispersive SPE) cleanup, and high-performance liquid chromatography ( HPLC) coupled with a fluorescence detector for confirmation and quantitation. Compared with conventional SPE cleanup, dispersive SPE greatly simplified and accelerated sample cleanup and was less time-consuming. Average recoveries of fortified samples were more than 80% for all estrogens except 4-OHE2, which had an average recovery of 60%. The results showed good repeatability that the variation coefficients of the instrument precision and the method were less than 8% and 13%, respectively. The relative standard deviation (RSD) of intraday repeatability tests was generally less than 12%. This method was able to demonstrate quantitative recoveries and provide confirmatory data for unambiguous analyte identification.