Dummy molecularly imprinted polymer for selective screening of trace bisphenols in river water

Bisphenols (BPs) are potential endocrine-disrupting chemicals that may adversely affect human health and wildlife. The complexity of matrix encountered in real-world samples renders screening of trace BPs a formidable challenge. The present study highlighted the potential of molecularly imprinted solid-phase extraction (MISPE) for selective detection of trace bisphenols and their halogenated analogues in surface water. The template bleeding was observed at parts-per-billion levels, deteriorating the accuracy and precision of BPs quantification. To surmount this problem, a dummy MISPE strategy was proposed, in which bisphenol E (BPE) was selected as a dummy template for molecularly imprinted polymer (MIP) synthesis. Coupling this MISPE strategy with chromatographic analysis, a dummy MISPE-HPLC method was established. The linearity, precision, limit of detection (LOD) and recovery were then validated. The linearity of the calibration curve for each BP was observed over the range of 20-2000 ng L^-1 (r > 0.998). LOD for each bisphenol was measured as low as 2.5-5.0 ng L^-1. This technique was applied to simultaneous screening of BPs in the Qinghe River, and five bisphenols were found within the concentration range of 0-224 ng L^-1 in river samples. The designed dummy MIP was superior to the commercial sorbents with regard to the selectivity, cross-reactivity, matrix removal efficiency and reusability. These merits enabled the applications of dummy MISPE for selective extraction and sensitive screening of BPs in environmental water samples. This method also provided a promising tool for monitoring the occurrence, distribution and fate of BPs in surface water.