Preparation of a multi-hollow magnetic molecularly imprinted polymer for the selective enrichment of indolebutyric acid

A simple strategy was developed for the preparation of multi-hollow magnetic molecularly imprinted polymers by incorporating 3-indolebutyric acid and ferroferric oxide nanoparticles simultaneously into a poly(styrene-co-methacrylic acid) copolymer matrix. The as prepared absorbents were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy and mercury porosimetry. The adsorption isotherms of indolebutyric acid revealed that there are two types of affinity binding sites in the absorbents. The apparent maximum binding capacity and dissociation constant were 17.88 mg/g and 158.7 mu g/mL for high-affinity binding sites and 9.310 mg/g and 35.04 mu g/mL for low-affinity binding sites, respectively. The results testified that multi-hollow magnetic molecularly imprinted polymers possessed excellent recognition capacity and fast kinetic binding behavior to the objective molecules due to the high specific surface area as large as 511.3 m(2)/g. Recoveries of 75.5-86.8% were obtained for the indolebutyric acid spiked at three concentration levels in blank and pear samples.