Simultaneous removal of anti-inflammatory pharmaceutical compounds from an aqueous mixture with adsorption onto chitosan zwitterionic derivative

Abstract The goal of this work was the application of a synthesized cross-linked and grafted zwitterionic chitosan derivative to the removal of a mixture of five anti-inflammatory compounds from aqueous matrix. This floating polymer supported nanocomposite material consisting of bio-based chitosan (CS) and was synthesized by free radical polymerization, using acrylic monomer [2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (MEDSP) as grafting agent. The composition and morphology of new CS-MEDSP material was characterized before and after adsorption, by using different procedures, for instance Fourier Transform Infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and Scanning electron microscopy (SEM). As model pollutants a mixture of pharmaceuticals from the group of anti-inflammatories was employed: diclofenac, ibuprofen, ketoprofen, paracetamol and salicylic acid (equal concentrations). An adsorption assessment was performed at different pH values concluding that pH = 4 was the optimum value. By testing different isotherm equations, the equilibrium data for the adsorption of the target compounds were evaluated. For the detection of compounds, an LC-MS system was utilized, in both ionization modes. Accordingly, results indicated a high adsorption/desorption ability of tested material being suitable for disposal of the certain remedies from aqueous systems.