A novel sorbent for solid-phase extraction coupling to high performance liquid chromatography for the determination of olaquindox in fish feed

A new and hydrophilic molecularly imprinted polymer (MIP) selective for olaquindox was prepared by bulk polymerisation using methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the crosslinker. The synthesised polymer was characterised by Fourier-transform infrared and static adsorption experiments. Results showed that the MIP had good recognition and selective ability for olaquindox. A novel method based on molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography was developed for the separation and determination of trace olaquindox in feed samples. Under selected experimental conditions, the detection limit (signal-to-noise ratio = 3) was 42.2 ng/g, and the relative standard deviation (RSD) for five replicate extractions of 50 µg/l olaquindox was 4.9%. The method provided high recoveries ranging from 89.8% to 93.1% at three spiked levels with < 5% RSDs. This method was successfully applied for the analysis of olaquindox in feed.