Synthesis of Urea and Magnetite-Based Chitin as Adsorbents for the Removal of Amlodipine Besylate

Abstract

Objective: Development of urea and magnetite-based chitin adsorbents for the removal of amlodipine besylate. Methods: Amlodipine is a calcium channel blocker widely used to treat hypertension and angina. However, it is important to treat the residues before disposal so they do not pollute the effluent water sources. The amlodipine sorption property of chitin-based subtract (CBS) was improved by treatment with magnetite and urea, followed by pyrolysis at 500 °C. The FT-IR characterization, elemental composition, pore properties, and sorption isotherms were also assessed. Results: The sorption capacity of amlodipine increased from 4.6 to 9.3 mg/g for the urea and magnetite-treated products, respectively. Further, modified chitin products showed a pore volume (micro and mesopore composition), pore percentage, and roughness of 0.01 cm3g-1, 0.02 cm3g-1, 32% and 68%, and 1.2, respectively. The CBS and derivatives did not present Langmurian behavior, indicating a characteristic heterogeneous surface and the presence of energetically distinct sorption sites. The sorption equilibrium was achieved within 5 min, resulting in a net physical sorption. Conclusion: The insertion of nitrogen and iron moieties on the surface of chitin improved the adsorption capacity of amlodipine.