Monitoring of Carbendazim and Thiabendazole in Fruits and Vegetables by SiO2@NiO-Based Solid-Phase Extraction Coupled to High-Performance Liquid Chromatography-Fluorescence Detector

Abstract

This study presents an application of nickel affinity solid-phase extraction (SPE) for the quantitative monitoring of carbendazim and thiabendazole residues in some fruits and vegetables. The nickel oxide nanoparticle was deposited on the silica to obtain an affinity adsorbent (SiO2@NiO) for the selective extraction of the compounds containing imidazole groups from complex matrix. Coupling with high-performance liquid chromatography with a fluorescence detector, the extraction conditions of the SiO2@NiO adsorbent for the carbendazim and thiabendazole were optimized, and a sensitive quantitative method with good linearities (R 2 > 0.998) in the range of 10–1000 ng g−1 was developed. The detection limits for the two analytes were in the range of 2.9–7.5 ng g−1, which are lower than the maximum residue limits established for these compounds. Relative standard deviations (RSDs) of intra-day and inter-day precisions were less than 8.8%, which showed perfect repeatability. The proposed method has been successfully applied to analyze carbendazim and thiabendazole in apples, pears, cucumbers, potatoes, cabbages, and eggplants. Good recoveries of carbendazim and thiabendazole spiked in fruits and vegetables were found to range from 80.0 to 115.4%, demonstrating that the proposed method was reliable in monitoring these two benzimidazoles in fruits and vegetables.