Porous capillary monolithic column coupled with ultrahigh performance liquid chromatography-tandem mass spectrometry for fast and effective separation and determination of estrogens

In this work, a porous capillary monolithic column was simply prepared by in situ thiol-alkyne click polymerization of dipentaerythritol hexakis (3-mercaptopropionate) and dimethyl dipropargylmalonate in fused-silica capillary. The capillary monolithic column shows excellent permeability, high porosity, and thoiether-rich groups, thereby, a high-efficient capacity for trace estrogens from complex samples are obtained via electron-donor-acceptor π-π interaction and hydrophobic interaction. The highest adsorption efficiency for estrogens is achieved at pH = 7.0 with a flow rate of 0.200 mL min−1. The superior adsorption capacities of the as-prepared capillary column for eight estrogens range from 0.092 mg m−1 to 0.31 mg m−1. A simple, reliable, and sensitive method for the determination of eight estrogens in biological and environmental samples is developed using the monolithic polymer as in-tube solid-phase microextraction coupled with ultrahigh performance liquid chromatography-tandem mass spectrometry (SPME-UPLC-MS/MS), and the total instrumental analysis time for the SPME-UPLC-MS/MS procedures was about 60 min per sample. The developed method shows a wide linear range (0.0500–5.00 μg L−1), and low limits of detection (5.34–9.63 ng L−1) for estrogens. The concentrations of estrogens in serum, urine, and pond water samples are found to be no more than 3.69, 0.741, and 1.04 μg L−1, respectively, and the satisfying recoveries for the eight estrogens range from 80.3% to 113% with relative standard deviations (n = 5) of 1.5–9.4%. The established method is highly potential for extraction and analysis of ultratrace target estrogens in complex matrices, such as biological and environmental samples.