Application of magnetic hydroxyapatite surface-imprinted polymers in pretreatment for detection of zearalenone in cereal samples

Abstract

This study is about the combination of magnetic solid phase extraction (MSPE) and high performance liquid chromatography-fluorescence detector (HPLC-FLD) for the pre-concentration and determination of Zearalenone (ZEA) in grain sample extracts. The novel sorbent (Fe3O4-HAP@MIPs), for selective and intelligent extraction of ZEA, was synthesized by doping Fe3O4 into the fibrous structure of hydroxyapatite nanoparticle (Fe3O4-HAP) and subsequently wrapping with molecularly imprinted polymers. The characteristic and morphology of magnetic particles were studied by infrared spectroscopy, vibrating sample magnetometer and scanning electron microscopy. The maximum adsorption capacity was 2.89 μg/mg. It could reach the adsorption equilibrium within 5 min. The adsorption isotherm of ZEA by the Fe3O4-HAP@MIPs were simulated. The results showed that the extraction process of ZEA with the sorbent accorded with Langmuir isotherm. The important factors affecting the extraction efficiency include elution solvent, washing solvent and the volume of them. After a serious of experiments, the optimum conditions were as follows: the volume of elution solvent was 4 mL of methanol and the washing solvent was acetonitrile–water 2:8（v/v). The calibration curve for ZEA was linear in the range of 10.00–300.00 μg/kg. The limit of detection and limit of quantitative was 2.00 μg/kg and 6.65 μg/kg, respectively. This method could provide a good reusability of 8 times and enough recoveries at three spiked levels (3, 5 and 8 ng/mL) ranging between 61.97% and 95.15% with the relative standard deviations of 1.94%∼7.44%. These results demonstrated that Fe3O4-HAP@MIPs could be used for separation, concentration and detection of ZEA from real samples.