Preparation of an allyloxy-cucurbit[6]uril-modified polymer monolithic column for microextraction of estrogens in cosmetics

In the present study, a poly(butyl methacrylate-co-ethylene dimethacrylate) (poly(BMA–EDMA)) monolithic column modified with allyloxy-cucurbit[6]uril (ACB[6]) was prepared with an in situ polymerization process. A polymer monolith microextraction method was developed with the modified monolithic column for the preconcentration of estrogen combined with high performance liquid chromatography. The various experimental parameters affecting the extraction capacity were investigated and optimized with an orthogonal experiment design, L16(45). Under the optimum conditions, we obtained acceptable linearities, low limits of detection, and good intra-day/inter-day relative standard deviations. Hydrophobic interactions, π–π stacking, and hydrogen bonding interactions contributed to the extraction efficiency of the ACB[6]@poly(BMA–EDMA) monolithic column. The present method was employed to determine estrogens in cosmetic samples and the accuracy was assessed through recovery experiments. The obtained recovery values were in the range of 80.1–109.4% with relative standard deviations less than 9.9%.