Recognition and adsorption characteristics of tramadol hydrochloride molecules in molecular imprinted poly(MAA-co-EGDMA)

A simple method for adsorption and recognition of tramadol-HCl in molecular imprinted poly (methacrylic acid-co-ethylene glycol dimethacrylate); poly (MAA-co-EGDMA), is described. Seven tramadol imprinted polymers (TIPs) were synthesized based on tramadol hydrochloride as the template molecule, methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, chloroform as a porogenic solvent and benzoyl peroxide (BP) as an initiator. Other seven non-imprinted polymers (NIPs) were prepared with the same compositions as the TIPs without the template molecule. A simple method for determination of Tramadol concentration by optical absorption method was described. The effects of crosslinker and functional monomer concentration, soaking time and the pH on the adsorption efficiency of tramadol by the polymers were studied. TIPs exhibited more adsorption affinity than their NIPs counterparts as they acquired recognition sites to capture the tramadol molecules. The TIP polymer with 15 mmol EGDMA and 1.15 mmol MAA stirred for 3h at 7 pH tramadol solution showed 90% adsorption capability for the tramadol, while the corresponding NIP sample showed 55.6% adsorption. SEM images showed the presence of (micro/meso/macro) pores in such TIP sample.