Recognition mechanism of water-compatible molecularly imprinted solid-phase extraction and determination of nine quinolones in urine by high performance liquid chromatography

Novel water-compatible molecularly imprinted polymers (MIPs) were synthesized in methanol–water systems with ofloxacin as templates and methacryclic acid as functional monomers. The MIPs were used as a special sorbent for the selective solid-phase extraction (SPE) of nine quinolones from urine samples, showing high affinity to the quinolones in aqueous environment. Its molecular recognition mechanisms were investigated by the molecular simulation and the experimental validation with UV and infrared spectrogram as well as 1H NMR. Binding capability and chromatographic characteristic were also evaluated. By using the water-compatible MIPs as SPE sorbents, the nine quinolones can be selectively extracted and enriched, while all matrices interferences were eliminated simultaneously. Under the optimal conditions of SPE and high performance liquid chromatography (HPLC), the good linearity of the method was obtained in a range of 0.05–30 μg/mL with the correlation coefficient of >0.999 and the relative standard division of 2.0–7.4%. The detection limits (s/n = 3) were in a range of 0.036–0.10 μg/mL. The proposed method was successfully applied for the selective extraction and separation of the studied quinolones in urine samples.