Restricted access medium magnetic molecularly imprinted polymers: Validation of their suitability as an effective quantitation tool against phthalates in food products packaged in plastic

A highly effective approach has been established for the selective identification and isolation for a list of phthalates (PTHs: e.g., dimethyl phthalate, dipropyl phthalate, dibutyl phthalate, benzyl butyl phthalate, and dioctyl phthalate) based on restricted access medium magnetic molecularly imprinted polymer (RAM-MMIP). The RAM-MMIP has been synthesized by a surface imprinting method using: (i) Fe₃O₄@SiO₂ as the support material, (ii) diethyl phthalate and dicyclohexyl phthalate as dual dummy templates, and (iii) (3-glycidyloxypropyl)trimethoxysilane as the silane coupling agent to impart hydrophilic properties to the polymer. The adsorption kinetic and isotherm studies confirm the good match of experimental results with the Langmuir and pseudo-second order model. The RAM-MMIP exhibits great selectivity toward PTHs and recyclability for up to seven cycles. It has been applied for the extraction of PTHs from foods packaged in plastic (bottled water, juice, and milk samples) via magnetic solid phase extraction coupled with gas chromatography/mass spectrometry (recovery: 88.53–121.57 % (RSD% = 1.30–5.15 %) and LOD (0.01–0.03 ng/mL)). The overall results of this study suggest that the RAM-MMIP is a highly recommendable option for efficient extraction and quantitation of PTHs.