Polyamidoamine Dendrimer Modified Silica Nanoparticles: A Promising Sorbent for Benzoylurea Insecticides Detection in Tea Infusions

This research aims to develop a precise and efficient dispersive solid-phase microextraction (DSPE) technique using third-generation polyamidoamine (PAMAM) dendrimer-grafted nanoparticles to quantify benzoylurea pesticides in green tea, black tea, and oolong tea infusions. The extraction efficiency is optimized through single-factor adjustments of key parameters, including adsorbent quantity (5-20 mg), adsorption duration (5-20 min), desorbent identity (methanol, acetonitrile), volume (100-600 μL), sodium chloride concentration (0-10%, m/v), and sample solution pH (3-8). The optimized method demonstrates linearity in the range of 2-500 μg L-1, with limits of detection (LODs) ranging from 0.6-1.5 μg L-1 and limits of quantification (LOQs) from 2.0 5.0 μg L-1. Recovery rates of 81.2-96.0% are achieved, with intra-day relative standard deviations (RSDs) of 1.4-2.8% and inter-day relative standard deviations of 2.0-3.9%, indicating high accuracy and repeatability. The successful application of detecting residues in commercial tea samples underscores the strong potential of the technique to determine benzoylurea analyte levels.