Determination of Estrogens in Milk Samples by Magnetic‐Solid‐Phase Extraction Technique Coupled With High‐Performance Liquid Chromatography

Abstract

A magnetic-solid-phase extraction method coupled with high-performance liquid chromatography and diode array detection has been developed for simultaneous determination of 3 estrogens in milk samples. In this work, Fe3O4 NPs were synthesized by a simple chemical co-precipitation reaction, and the surface of Fe3O4 was modified with cetyltrimethyl ammonium bromide (CTAB; designed as Fe3O4@CTAB). The synthesized Fe3O4@CTAB NPs were characterized by Fourier transformed infrared spectroscopy, scanning electron microscopy, and transmission electron microscope. Fe3O4@CTAB NPs have high binding affinity toward estrone (E1), 17β-estradiol (17β-E2), and diethylstilbestrol (DES). Fe3O4@CTAB NPs can be easily separated from sample solutions using an external magnet due to the high super-paramagnetic property. The separation, preconcentration procedure is fast and will be completed in 2 min. Estrogens linear dynamic ranges were achieved in the range of 10 to 1000 ng/mL with regression coefficients (R(2)) higher than 0.9992. The limits of detection were between 0.26 and 0.61 ng/mL. Parameters influencing the recoveries were investigated and optimized. The proposed method was used for the determination of E1, 17β-E2, and DES in milk samples, and recoveries were ranged from 91.3% to 105.0%, with the relative standard deviations in the range of 2.7% to 4.0%.

Determination of Mirabegron in rat plasma by UPLC–MS/MS after oral and intravenous administration

“…The ion source parameters were optimized to get a proper response. Solid-phase extraction and Liquid-liquid extraction are effective means to improve the sensitivity and robustness of assays 16,17 . However, both of them are time-consuming and expensive and may result in environmental pollution.…”

A magnetic relaxation switch sensor for determination of 17β‐estradiol in milk and eggs based on aptamer‐functionalized Fe3O4@Au nanoparticles

“…Up to now, several analytical techniques, such as high-performance liquid chromatography (HPLC), 10,11 gas chromatography-mass spectrometry (GC-MS), [12][13][14] and liquid chromatography-mass spectrometry (LC-MS), 15,16 have been successfully employed for E 2 detection. Although these methods possess high selectivity and sensitivity, it is undeniable that they require expensive equipment, skilled operators, complicated pretreatment, usage of harmful solvents, and timeconsuming process.…”

Mycoestrogen determination in cow milk: Magnetic solid‐phase extraction followed by liquid chromatography and tandem mass spectrometry analysis

“…MSPE has never been used for mycoestrogens determination in milk, whereas MNPs with various coating have been employed for extracting estrogens from milk: polypyrrole , CNTs , and cetyltrimethyl ammonium bromide .…”