Development of dual-templates molecularly imprinted stir bar sorptive extraction and its application for the analysis of environmental estrogens in water and plastic samples

In this study, a novel dual-template molecularly imprinted polymer (MIP)-coated stir bar was prepared and coupled with high-performance liquid chromatography (HPLC) for the analysis of environmental estrogens in complex samples. Dual-template MIP coating was homogeneous and porous with an average thickness of 5 μm. Moreover, it could be used for at least 50 times and be kept for at least 12 months in a dryer without any damage. The MIP-coated stir bar showed excellent selectivity to bisphenols and steroids. The method for the determination of bisphenols and steroids in complex samples via MIP-coated stir bar sorptive extraction coupled with HPLC was developed. The method was successfully applied in the analysis of five estrogens in lake and river water samples with recoveries of 71.2- 96.4% and 62.8-98.0%, respectively. The method was also successfully applied to the analysis of five estrogens in three plastic samples with recoveries of 67.7-99.1%, 68.8-99.9%, and 74.8-101.8%. The limit of quantitation was 1.0-5.0 μg/L. The proposed method is suitable for the simultaneous determination of multiple trace environmental estrogens in water and plastic samples.