Detection of trace estrogens in environmental water by multi-template molecularly imprinted polymers based magnetic solid phase extraction coupled solidified floating organic drop microextraction and HPLC

Estrogens are emerging environmental contaminants due to their harmful impact on ecological environment and human health. Because estrogens usually exist at very low levels in water environment with complicated matrix, sensitive and accurate determination of trace estrogens in various environmental water samples is a challenging issue. This work developed a new method for simultaneous trace detection of estrogens in aqueous solution by combining multi-template estrogen molecularly imprinted polymers (MIPs) based magnetic solid phase extraction (MSPE) with solidification of floating organic drop (SFO) based dispersive liquid–liquid microextraction (DLLME) and high performance liquid chromatography. The E-MIPs acted as the adsorbent of MSPE for simultaneous selective extraction of multi-estrogens from water. The eluent of MSPE was further concentrated by SFO-DLLME. A series of experiments were performed to optimize the extraction conditions of MSPE and DLLME, and the obtained results were as follows: solution pH 8.0, 1.5 mL of MeOH/HAc (9:1, v:v) as the eluent, 50 μL of 1-dodecanol as the extractant, extraction for 5 min and using 3 % NaCl. Under the optimum conditions, the detection limits for the selected estrogens were 0.29–1.11 μg L −1 , which were comparable with or even lower than those achieved by using HPLC-MS/MS. The recoveries of estrogens were 90.5–107.0 % in the determination of various environment water samples with RSDs of 1.5–7.0 %. Therefore, the proposed multi-template MIPs-MSPE-DLLME-HPLC method is selective, sensitive, accurate, rapid and without the need of very expensive instrument, which offers a practical approach for the simultaneous trace analysis of estrogens in water.