ABSTRACT
A novel magnetic molecularly imprinted polymer for the selective recognition of auramine O was rationally designed via screening from a library of nonimprinted polymers. A stoichiometric ratio of functional monomer (itaconic acid) and template molecule (auramine O) was found to be 1.5. Meanwhile, the synthesized SiO2 @Fe3 O4 was modified by 0.5 mol/L hydrochloric acid to facilitate the preparation of magnetic molecularly imprinted polymer particles. Adsorption experiments showed that the magnetic polymer particles exhibited good selectivity, recoveries, and enrichment performance. The stoichiometric imprinted polymers have been employed for the selective preconcentration of auramine O from lake water sample. The high specificity of the stoichiometric imprinted polymers was proven in the extraction of mixture solution of auramine O, auramine O hydrochloride, and chrysoidine, and the recoveries ranged between 99.66 and 108.75% (RSD 2.6-3.7%, n = 3) for lake water. These results suggest that this method is effective and can be successfully applied to the analysis of auramine O in environmental water samples.
ABSTRACT
In the present paper, we describe a new on-line SPE system where molecular imprinting, fiber-optic detection and flow injection analysis were combined for the first time. This new system has been applied for the on line detection of 4-nitrophenol (4-NP). Initially, molecularly imprinted polymers (MIP) have been prepared for the selective extraction of 4-NP using 4-vinylpyridine and ethylene glycol dimethacrylate as functional and cross-linking monomers, respectively. Selective extraction was achieved using the designed MIP with 97% of recovery on imprinted polymer and 10% on control polymer. The system provided a high degree of accuracy, with RSDs varying between 0.7 and 1.39%. In respect of accuracy, reproducibility, and rapidity, this system is comparable with HPLC. In short, the system allows simple, fast, and accurate analyte determination with the possibility of future automation.