Abstract:

Molecular imprinting technology was employed to produce one kind of rhodamine B(RhB) molecularly imprinted polymer(MIP) microspheres by precipitation polymerization using RhB, acrylamide, ethylene glycol dimethacrylatea(EGDMA), azobisisobutyronitrile(AIBN), and acetonitrile as template, functional monomer, cross-linking agent, initiator and porogen, respectively. The resultant microspheres were characterized by scanning electron microscopy. The binding constant and chemical combination ratio of the complex formed between the template and the functional monomer were obtained by UV spectrophotometry, which showed that the RhB-monomer forms 1∶1 complexes and the binding constant is 5.3×103 L/mol. The effects of types and volumes of the porogen on the size and the uniformity of microspheres were also discussed. After packing the microspheres into column, it was used to absorb RhB from red pepper. The extraction conditions of molecular imprinting solid phase extraction(MISPE) column for RhB were optimized. Pepper samples spiked with RhB were extracted by MISPE column and analyzed by high performance liquid chromatography. The recoveries of MISPE column for RhB extraction were found to be 91.7%～103.5%, indicating the feasibility of the prepared MIPs for RhB extraction.

Key words: molecularly imprinted polymer microspheres, rhodamine B, precipitation polymerization, ultraviolet spectrophotometry, solid phase extraction