Magnetic-graphene oxide based molecularly imprinted polymers for selective extraction of microsystin-LR prior to the determination by HPLC

A novel magnetic molecularly imprinted polymer on a magnetic graphene oxide surface, GO@Fe3O4-MIP, was successfully synthesized and applied as adsorbent for the extraction of microcystin-LR (MC-LR) from water samples prior to analysis using high performance liquid chromatography (HPLC). A variety of characterizations have proven successful preparation of this material. The GO@Fe3O4-MIPs showed high adsorption capacity with maximum adsorption capacity of 1.24 mg/g, fast adsorption rate (25 min) and high selectivity toward MC-LR. The adsorption processes followed the Freundlich isotherm and pseudo-second-order kinetic models. Various extraction conditions were optimized. The linearity of the method was studied from 2 to 10,000 mu g/L, obtaining a correlation coefficient of 0.9985. The limit of detection was calculated as 0.08 mu g/L (S/N = 3), and the recoveries from spiked samples were 86%-113%, with relative standard deviations of 1.0%-6.8%. The developed method was suitable for the rapid and sensitive determination of MC-LR in water samples.