Bifunctional monomer molecularly imprinted sol-gel polymers based on the surface of magnetic halloysite nanotubes as an effective extraction approach for norfloxacin

An effective magnetic surface imprinted polymer with high adsorption ability and selectivity has been designed. Three magnetic halloysite nanotubes combined with molecularly imprinted polymer (MMIP) composites were fabricated. Halloysite nanotubes (Hal nanotubes) were us as supporting matrix, norfloxacin (NOR) as template molecules, Aminopropyltriethoxysilane (3-APTES) and Methacryloxypropyltrimethoxysilane (MTEOS) used as monomers and tetramethyl orthosilicate (TEOS) as cross linker through a one-pot sol-gel polymerization. The resulting MMIP were characterized by various techniques. The adsorption isotherms, adsorption kinetics and selective recognition of MMIP were investigated in detail. The imprinted polymers with bifunctional monomer possess the highest adsorption capacity (312.08 μg·mg−1) and the best select factor (5.41). After optimization of solid phase extraction (SPE) condition, imprinted polymer with bifunctional monomer possess the best extraction ability and can be successfully applied into the extraction of norfloxacin in lake water. In addition, the SPE-ultraviolet method established possesses good accuracy and precision. Hydrochloric acid (9:1/v:v) could be used as the best elution and the magnetic imprinted polymer could be reused for at least seven times.