Graphene oxide based molecularly imprinted polymers modified with β-cyclodextrin for selective extraction of di(2-ethylhexyl) phthalate in environmental waters.

Graphene oxide based molecularly imprinted polymers modified with β-cyclodextrin were prepared as solid-phase extraction column sorbents for specific recognition and sensitive detection of di(2-ethylhexyl) phthalate in water samples. The morphology and composition of synthesized sorbents were characterized by scanning electron microscopy, thermo-gravimetric analysis, Raman spectroscopy, and Fourier-transform infrared spectroscopy. The conditions affecting the performance of extraction procedures such as desorption solvent types and volume, sample pH and volume were investigated. The loading capacity (8.2 μg/mg) of the prepared sorbents increased eight times after modification with β-cyclodextrin. The developed extraction procedures coupled to high-performance liquid chromatography exhibited good linearity (0.2-500 μg/L), low limit of detection (0.052 μg/L), and good precision (relative standard deviation˂5.7%) under optimized conditions. The developed solid-phase extraction technique with prepared sorbents has been successfully applied in extracting trace di(2-ethylhexyl) phthalate from real natural waters with high efficiency, good selectivity, and desirable recoveries.