Highly class-selective solid-phase extraction of bisphenols in milk, sediment and human urine samples using well-designed dummy molecularly imprinted polymers.

Dummy molecularly imprinted polymers (DMIPs) towards bisphenols (BPs) were prepared employing 1,1,1-tris(4-hydroxyphenyl)ethane (THPE) and phenolphthalein (PP) as dummy templates. The selectivity of the resulting DMIPs was evaluated by high-performance liquid chromatography (HPLC). Both PP-DMIP and THPE-DMIP showed excellent class selectivity towards bisphenols. THPE-DMIP prepared using the template molecule with three hydroxyphenyl functionalities achieved higher imprinting factors (IF) for the bisphenols over a range of 7.9-19.8. An efficient approach based on dummy molecularly imprinted solid phase extraction (DMISPE) coupled with HPLC-DAD was developed for selective extraction of eight bisphenols in sediment, milk and human urine samples using THPE-DMIP as sorbents. The method showed good recoveries (82-102%) and precision (RSD 0.2-4%, n=3) for these samples spiked at two concentration levels (25 and 250ngg(-1) or ngmL(-1)). The detection limits ranged between 0.6 and 1.1ngg(-1) or ngmL(-1). Efficient removal of sample matrix and interferences was also achieved for these samples after DMISPE process. The results demonstrated great potential of the optimized methods for sample preparation in the routine analysis of trace BPs in complex samples.