Molecularly imprinted monolithic column based on functionalized β-cyclodextrin and multi-walled carbon nanotubes for selective recognition of benzimidazole residues in citrus samples

Benzimidazole pesticides are widely used and their amount of residue in fruits and vegetables can indirectly affect the human life. A novel molecularly imprinted monolithic column based on acryloyl-beta-cyclodextrin (A-beta-CD) and silanized multi-walled carbon nanotubes (SMWNTs) was successfully prepared for selective recognition of benzimidazole residues in citrus samples. Using A-beta-CD and methacrylic acid as functional monomers and SMWNTs as modified materials, monolithic column was synthesized by in-situ polymerization. Synthetic conditions of the column were optimized by the response surface methodology. Under optimal conditions, the adsorption behaviors of the column were evaluated by varying flow rate, pH and solvent. The selectivity of the column was tested with structurally similar analogues of benzimidazoles. This column was successfully applied to the simultaneous extraction of thiabendazole, carbendazim and fuberidazole in citrus samples. The column provided a convenient, sensitive, selective and reliable solution for recognizing these benzimidazole residues from citrus samples, and it could be reused at least 20 times without significant loss of absorption efficiency.