Preparation and application of a magnetic plasticizer as a molecularly imprinted polymer adsorbing material for the determination of phthalic acid esters in aqueous samples.

A novel magnetic plasticizer molecularly imprinted polymer adsorbing material (MIP@mSiO2 -β-CD@Fe3 O4 ) was successfully synthesized for the determination of six phthalic acid esters in water, milk, and wine samples. The molecularly imprinted polymers were prepared via precipitation polymerization and a surface molecular imprinting technique, using a cyclodextrin-modified magnetic meso-porous material (mSiO2 -β-CD@Fe3 O4 ) as a magnetic supporter, dibutyl phthalate and butyl benzyl phthalate as the dual template molecules, methacrylic acid as the functional monomer, and ethyleneglycol dimethacrylate as the cross-linking agent. The polymers were characterized by scanning electron microscopy, IR spectroscopy, and X-ray powder diffraction. Thermogravimetric analysis and static and dynamic adsorption experiments were carried out to assay its stability and selectivity. Under optimal experimental conditions, a magnetic solid-phase extraction with MIP@mSiO2 -β-CD@Fe3 O4 coupled to gas chromatography and mass spectrometry method was successfully developed for the determination of phthalic acid esters. The established method achieved a good linear range of 0.10∼8.00 μg/mL (R > 0.99) and a low detection limit within the range of 1.0∼5.0 μg/L. An average recovery rate of 80.2∼103% with relative standard deviation < 6.7% was obtained upon the application of the developed method to detect phthalic acid esters in actual aqueous samples.