Performance of a Molecularly Imprinted Bifunctional Adsorbent Poly(methacrylic acid-phenyltrimetoxysilane) for High-Throughput Solid Phase Extraction of Diuron in Waters and Soymilk Samples

Abstract

This study reports the development of a novel high-throughput solid-phase extraction (SPE) method using a hybrid bifunctional organic-inorganic molecularly imprinted polymer (BHMIP) for the selective preconcentration of diuron in environmental waters and soymilk. The BHMIP was synthesized with methacrylic acid and phenyltrimethoxysilane as organic and inorganic monomers. The method involves preconcentration of 50.0 mL of sample through 150.0 mg of BHMIP at a high flow rate (14.0 mL min^-1), followed by elution with 6.0 mL of methanol and analysis by high-performance liquid chromatography with diode array detector (HPLC-DAD). It showed excellent linearity (0.27-200.0 μg L^-1, coefficient of determination (R²) = 0.999), with limits of detection and quantification of 0.08 and 0.27 μg L^-1, respectively. A high preconcentration factor of 173-fold was achieved. The method was successfully applied to surface water and soymilk samples, with recovery rates of 92-104% and 93-110%, confirming negligible matrix effects. Precision assays yielded relative standard deviations of 3.16-4.07% at two concentration levels. The BHMIP demonstrated efficient clean-up of complex matrices without loss of extraction efficiency, enabling sensitive detection of diuron at trace levels. This validates the method as a robust, selective, and reliable tool for monitoring diuron residues in environmental and food samples.

Keywords:
diuron; MIP; hybrid polymer; soymilk