Magnetic nanoparticles based dispersive micro-solid-phase extraction as a novel technique for the determination of estrogens in pork samples.

A simple and rapid magnetic nanoparticles (MNPs) based dispersive micro-solid-phase extraction (D-μ-SPE) method coupled with HPLC-DAD has been proposed for simultaneous determination of three estrogens (17β-estradiol (E2), estrone (E1) and diethylstilbestrol (DES)) in pork samples. In this paper, the synthesis of cetyltrimethyl ammonium bromide (CTAB)-coated Fe3O4@caprylic acid NPs as an efficient sorbent for its high surface area, excellent adsorption capacity, good dispersion ability and high super-paramagnetic property was successfully applied to adsorb estrogens. Vortex was used to enhance mass transfer rate as it provided mild and effective mixing of sample solution and increased the contact between analytes and MNPs. The parameters affecting the extraction efficiency were investigated in detail. The dosages of sorbent and eluate are 100μL and 500μL, respectively. The extraction equilibrium was achieved within 2min and the MNPs can be reused. The proposed technique provided high recoveries (93.3-106.7%), good linearity (0.9993-0.9999), low LODs (0.021-0.033ngmL(-1)) and repeatability (RSD%=1.87-2.92).