Synthesis of Molecularly Imprinted Polymers Coated on Silica Nanoparticles for Removal of P-Nitrophenol from Crude Pharmaceuticals

Abstract

This paper describes the preparation of molecularly imprinted polymer (MIP) layer-coated silica nanoparticles for separation and determination of p-nitrophenol from active pharmaceutical ingredients. A new MIP was synthesized using p-nitrophenol, methacrylic acid (functional monomer), MPTS (chemically modifier), silica nanoparticles, ethylene glycol dimethacrylate (cross-linker), 2,2′-azobisisobutironitril (intiator) and toluene – acetonitrile (porogenic solvent). The surface of silica nanoparticles (Si–NP) was modified by reaction with 3-)methacryloxy)propyltrimethoxylsilane. Then, MIP coated on silica nanoparticles was synthesized by copolymerization of the vinyl end groups with functional monomer, cross-linking agent, initiator, and template molecule and these particles were used for solid-phase extraction of p-nitrophenol. To compare the performance of this MIP, a control polymer or non-imprinted polymer (NIP) was prepared using the same method and same material without the template molecule. The synthesized polymers were characterized by FT-IR spectroscopy, XRD, and SEM techniques. Parameters such as adsorption time, solution pH, and type of eluent for the elution of impurities from MIP were optimized. Selectivity of the MIP for the absorption of p-nitrophenol was investigated through adsorption experiments and the results were compared with the adsorption of impurities by NIP.