Molecularly imprinted core-shell magnetic nanoparticles for selective extraction of triazines in soils.

In this work, a propazine-imprinted polymer was synthesized on the surface of modified magnetic nanoparticles to be used in the solid-phase extraction of triazines in soil samples. The effect of different solvents on the selective extraction of target analytes was assessed to establish the optimum rebinding conditions. The obtained magnetic molecularly imprinted particles exhibited high selectivity for triazines and were easily collected and separated by an external magnetic field without additional centrifugation or filtration steps. Under optimum conditions, a magnetic molecularly imprinted solid-phase extraction method was developed allowing the extraction of several triazines (desisopropylatrazine, desethylatrazine, simazine, atrazine, and propazine) from soil samples and their subsequent final determination by high-performance liquid chromatography with diode-array detection. Recoveries for the triazines studied were within the range 5.4% to 40.6%, with relative standard deviations lower than 7.0% (n = 3). The detection limits were within 0.1 to 3 ng g-1 , depending upon the triazine and the type of soil used.