Synthesis and application of a molecularly imprinted polymer for the selective adsorption of emtricitabine in river water and wastewater

Abstract In this work, a 2-vinylpyridine-based molecularly imprinted polymer (MIP) was synthesized, characterized, and applied for the adsorption of emtricitabine in river water, and wastewater treatment plant influent and effluent. Emtricitabine, 2-vinylpyridine, ethylene glycol dimethacrylate, 1,1´-azobis-(cyclo-hexanecarbonitrile), and toluene were used for the synthesis of MIP at 70 ℃ for 24 h as template, functional monomer, cross-linker, initiator, and porogen solvent, respectively. A non-imprinted polymer (NIP) was synthesized under the same conditions without a template molecule. The resulting polymers were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and X-ray diffraction. The adsorption of emtricitabine in aqueous solutions using the synthesized MIP followed a pseudo-second-order kinetic model and Freundlich adsorption isotherm. These results suggested that a multilayer chemisorption occurred on heterogeneous sites and controlled the adsorption rate. The adsorption performance of the MIP was superior when compared to that of NIP. The reusability studies revealed that MIP can be reused for 5 cycles with extraction efficiencies exceeding 80%. Furthermore, the extraction efficiency for MIP was above 80% for emtricitabine in the presence of competitors with a distribution coefficient of 1.62 mg g −1 . This translated to the adsorption capacity of 4.75, 4.71, and 4.65 mg g −1 for MIP in river water, effluent, and influent, respectively. The results demonstrated that the MIP exhibited high selectivity and extraction efficiency, indicating its potential application in the adsorption of emtricitabine in surface water and wastewater.